From 976897dd96db94c74209d0a0671d7a73aa02fab9 Mon Sep 17 00:00:00 2001 From: Lukasz Luba Date: Wed, 21 Aug 2019 12:42:58 +0200 Subject: [PATCH 1/5] memory: Extend of_memory with LPDDR3 support Add AC timings information needed to support LPDDR3 and memory controllers along with helpers to obtain it. These will be necessary for upcoming Exynos5422 Dynamic Memory Controller driver. Signed-off-by: Lukasz Luba Signed-off-by: Krzysztof Kozlowski --- drivers/memory/jedec_ddr.h | 61 +++++++++++++++ drivers/memory/of_memory.c | 149 +++++++++++++++++++++++++++++++++++++ drivers/memory/of_memory.h | 18 +++++ 3 files changed, 228 insertions(+) diff --git a/drivers/memory/jedec_ddr.h b/drivers/memory/jedec_ddr.h index 4a21b5044ff8..e59ccbd982d0 100644 --- a/drivers/memory/jedec_ddr.h +++ b/drivers/memory/jedec_ddr.h @@ -29,6 +29,7 @@ #define DDR_TYPE_LPDDR2_S4 3 #define DDR_TYPE_LPDDR2_S2 4 #define DDR_TYPE_LPDDR2_NVM 5 +#define DDR_TYPE_LPDDR3 6 /* DDR IO width */ #define DDR_IO_WIDTH_4 1 @@ -169,4 +170,64 @@ extern const struct lpddr2_timings lpddr2_jedec_timings[NUM_DDR_TIMING_TABLE_ENTRIES]; extern const struct lpddr2_min_tck lpddr2_jedec_min_tck; +/* + * Structure for timings for LPDDR3 based on LPDDR2 plus additional fields. + * All parameters are in pico seconds(ps) excluding max_freq, min_freq which + * are in Hz. + */ +struct lpddr3_timings { + u32 max_freq; + u32 min_freq; + u32 tRFC; + u32 tRRD; + u32 tRPab; + u32 tRPpb; + u32 tRCD; + u32 tRC; + u32 tRAS; + u32 tWTR; + u32 tWR; + u32 tRTP; + u32 tW2W_C2C; + u32 tR2R_C2C; + u32 tWL; + u32 tDQSCK; + u32 tRL; + u32 tFAW; + u32 tXSR; + u32 tXP; + u32 tCKE; + u32 tCKESR; + u32 tMRD; +}; + +/* + * Min value for some parameters in terms of number of tCK cycles(nCK) + * Please set to zero parameters that are not valid for a given memory + * type + */ +struct lpddr3_min_tck { + u32 tRFC; + u32 tRRD; + u32 tRPab; + u32 tRPpb; + u32 tRCD; + u32 tRC; + u32 tRAS; + u32 tWTR; + u32 tWR; + u32 tRTP; + u32 tW2W_C2C; + u32 tR2R_C2C; + u32 tWL; + u32 tDQSCK; + u32 tRL; + u32 tFAW; + u32 tXSR; + u32 tXP; + u32 tCKE; + u32 tCKESR; + u32 tMRD; +}; + #endif /* __JEDEC_DDR_H */ diff --git a/drivers/memory/of_memory.c b/drivers/memory/of_memory.c index 46539b27a3fb..71f26eac7350 100644 --- a/drivers/memory/of_memory.c +++ b/drivers/memory/of_memory.c @@ -3,6 +3,7 @@ * OpenFirmware helpers for memory drivers * * Copyright (C) 2012 Texas Instruments, Inc. + * Copyright (C) 2019 Samsung Electronics Co., Ltd. */ #include @@ -149,3 +150,151 @@ const struct lpddr2_timings *of_get_ddr_timings(struct device_node *np_ddr, return lpddr2_jedec_timings; } EXPORT_SYMBOL(of_get_ddr_timings); + +/** + * of_lpddr3_get_min_tck() - extract min timing values for lpddr3 + * @np: pointer to ddr device tree node + * @device: device requesting for min timing values + * + * Populates the lpddr3_min_tck structure by extracting data + * from device tree node. Returns a pointer to the populated + * structure. If any error in populating the structure, returns NULL. + */ +const struct lpddr3_min_tck *of_lpddr3_get_min_tck(struct device_node *np, + struct device *dev) +{ + int ret = 0; + struct lpddr3_min_tck *min; + + min = devm_kzalloc(dev, sizeof(*min), GFP_KERNEL); + if (!min) + goto default_min_tck; + + ret |= of_property_read_u32(np, "tRFC-min-tck", &min->tRFC); + ret |= of_property_read_u32(np, "tRRD-min-tck", &min->tRRD); + ret |= of_property_read_u32(np, "tRPab-min-tck", &min->tRPab); + ret |= of_property_read_u32(np, "tRPpb-min-tck", &min->tRPpb); + ret |= of_property_read_u32(np, "tRCD-min-tck", &min->tRCD); + ret |= of_property_read_u32(np, "tRC-min-tck", &min->tRC); + ret |= of_property_read_u32(np, "tRAS-min-tck", &min->tRAS); + ret |= of_property_read_u32(np, "tWTR-min-tck", &min->tWTR); + ret |= of_property_read_u32(np, "tWR-min-tck", &min->tWR); + ret |= of_property_read_u32(np, "tRTP-min-tck", &min->tRTP); + ret |= of_property_read_u32(np, "tW2W-C2C-min-tck", &min->tW2W_C2C); + ret |= of_property_read_u32(np, "tR2R-C2C-min-tck", &min->tR2R_C2C); + ret |= of_property_read_u32(np, "tWL-min-tck", &min->tWL); + ret |= of_property_read_u32(np, "tDQSCK-min-tck", &min->tDQSCK); + ret |= of_property_read_u32(np, "tRL-min-tck", &min->tRL); + ret |= of_property_read_u32(np, "tFAW-min-tck", &min->tFAW); + ret |= of_property_read_u32(np, "tXSR-min-tck", &min->tXSR); + ret |= of_property_read_u32(np, "tXP-min-tck", &min->tXP); + ret |= of_property_read_u32(np, "tCKE-min-tck", &min->tCKE); + ret |= of_property_read_u32(np, "tCKESR-min-tck", &min->tCKESR); + ret |= of_property_read_u32(np, "tMRD-min-tck", &min->tMRD); + + if (ret) { + dev_warn(dev, "%s: errors while parsing min-tck values\n", + __func__); + devm_kfree(dev, min); + goto default_min_tck; + } + + return min; + +default_min_tck: + dev_warn(dev, "%s: using default min-tck values\n", __func__); + return NULL; +} +EXPORT_SYMBOL(of_lpddr3_get_min_tck); + +static int of_lpddr3_do_get_timings(struct device_node *np, + struct lpddr3_timings *tim) +{ + int ret; + + /* The 'reg' param required since DT has changed, used as 'max-freq' */ + ret = of_property_read_u32(np, "reg", &tim->max_freq); + ret |= of_property_read_u32(np, "min-freq", &tim->min_freq); + ret |= of_property_read_u32(np, "tRFC", &tim->tRFC); + ret |= of_property_read_u32(np, "tRRD", &tim->tRRD); + ret |= of_property_read_u32(np, "tRPab", &tim->tRPab); + ret |= of_property_read_u32(np, "tRPpb", &tim->tRPpb); + ret |= of_property_read_u32(np, "tRCD", &tim->tRCD); + ret |= of_property_read_u32(np, "tRC", &tim->tRC); + ret |= of_property_read_u32(np, "tRAS", &tim->tRAS); + ret |= of_property_read_u32(np, "tWTR", &tim->tWTR); + ret |= of_property_read_u32(np, "tWR", &tim->tWR); + ret |= of_property_read_u32(np, "tRTP", &tim->tRTP); + ret |= of_property_read_u32(np, "tW2W-C2C", &tim->tW2W_C2C); + ret |= of_property_read_u32(np, "tR2R-C2C", &tim->tR2R_C2C); + ret |= of_property_read_u32(np, "tFAW", &tim->tFAW); + ret |= of_property_read_u32(np, "tXSR", &tim->tXSR); + ret |= of_property_read_u32(np, "tXP", &tim->tXP); + ret |= of_property_read_u32(np, "tCKE", &tim->tCKE); + ret |= of_property_read_u32(np, "tCKESR", &tim->tCKESR); + ret |= of_property_read_u32(np, "tMRD", &tim->tMRD); + + return ret; +} + +/** + * of_lpddr3_get_ddr_timings() - extracts the lpddr3 timings and updates no of + * frequencies available. + * @np_ddr: Pointer to ddr device tree node + * @dev: Device requesting for ddr timings + * @device_type: Type of ddr + * @nr_frequencies: No of frequencies available for ddr + * (updated by this function) + * + * Populates lpddr3_timings structure by extracting data from device + * tree node. Returns pointer to populated structure. If any error + * while populating, returns NULL. + */ +const struct lpddr3_timings +*of_lpddr3_get_ddr_timings(struct device_node *np_ddr, struct device *dev, + u32 device_type, u32 *nr_frequencies) +{ + struct lpddr3_timings *timings = NULL; + u32 arr_sz = 0, i = 0; + struct device_node *np_tim; + char *tim_compat = NULL; + + switch (device_type) { + case DDR_TYPE_LPDDR3: + tim_compat = "jedec,lpddr3-timings"; + break; + default: + dev_warn(dev, "%s: un-supported memory type\n", __func__); + } + + for_each_child_of_node(np_ddr, np_tim) + if (of_device_is_compatible(np_tim, tim_compat)) + arr_sz++; + + if (arr_sz) + timings = devm_kcalloc(dev, arr_sz, sizeof(*timings), + GFP_KERNEL); + + if (!timings) + goto default_timings; + + for_each_child_of_node(np_ddr, np_tim) { + if (of_device_is_compatible(np_tim, tim_compat)) { + if (of_lpddr3_do_get_timings(np_tim, &timings[i])) { + devm_kfree(dev, timings); + goto default_timings; + } + i++; + } + } + + *nr_frequencies = arr_sz; + + return timings; + +default_timings: + dev_warn(dev, "%s: failed to get timings\n", __func__); + *nr_frequencies = 0; + return NULL; +} +EXPORT_SYMBOL(of_lpddr3_get_ddr_timings); diff --git a/drivers/memory/of_memory.h b/drivers/memory/of_memory.h index b077cc836b0b..e39ecc4c733d 100644 --- a/drivers/memory/of_memory.h +++ b/drivers/memory/of_memory.h @@ -14,6 +14,11 @@ extern const struct lpddr2_min_tck *of_get_min_tck(struct device_node *np, extern const struct lpddr2_timings *of_get_ddr_timings(struct device_node *np_ddr, struct device *dev, u32 device_type, u32 *nr_frequencies); +extern const struct lpddr3_min_tck + *of_lpddr3_get_min_tck(struct device_node *np, struct device *dev); +extern const struct lpddr3_timings + *of_lpddr3_get_ddr_timings(struct device_node *np_ddr, + struct device *dev, u32 device_type, u32 *nr_frequencies); #else static inline const struct lpddr2_min_tck *of_get_min_tck(struct device_node *np, struct device *dev) @@ -27,6 +32,19 @@ static inline const struct lpddr2_timings { return NULL; } + +static inline const struct lpddr3_min_tck + *of_lpddr3_get_min_tck(struct device_node *np, struct device *dev) +{ + return NULL; +} + +static inline const struct lpddr3_timings + *of_lpddr3_get_ddr_timings(struct device_node *np_ddr, + struct device *dev, u32 device_type, u32 *nr_frequencies) +{ + return NULL; +} #endif /* CONFIG_OF && CONFIG_DDR */ #endif /* __LINUX_MEMORY_OF_REG_ */ From 6e7674c3c6df565ab47d02b4f2e608e3477cdf86 Mon Sep 17 00:00:00 2001 From: Lukasz Luba Date: Wed, 21 Aug 2019 12:43:00 +0200 Subject: [PATCH 2/5] memory: Add DMC driver for Exynos5422 Add driver for Exynos5422 Dynamic Memory Controller. The driver provides support for dynamic frequency and voltage scaling for DMC and DRAM. It supports changing timings of DRAM running with different frequency. There is also an algorithm to calculate timings based on memory description provided in DT. Signed-off-by: Lukasz Luba Signed-off-by: Krzysztof Kozlowski --- MAINTAINERS | 8 + drivers/memory/samsung/Kconfig | 13 + drivers/memory/samsung/Makefile | 1 + drivers/memory/samsung/exynos5422-dmc.c | 1257 +++++++++++++++++++++++ 4 files changed, 1279 insertions(+) create mode 100644 drivers/memory/samsung/exynos5422-dmc.c diff --git a/MAINTAINERS b/MAINTAINERS index 296de2b51c83..aba74a45cd0f 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -4969,6 +4969,14 @@ F: include/linux/dma-direct.h F: include/linux/dma-mapping.h F: include/linux/dma-noncoherent.h +DMC FREQUENCY DRIVER FOR SAMSUNG EXYNOS5422 +M: Lukasz Luba +L: linux-pm@vger.kernel.org +L: linux-samsung-soc@vger.kernel.org +S: Maintained +F: drivers/memory/samsung/exynos5422-dmc.c +F: Documentation/devicetree/bindings/memory-controllers/exynos5422-dmc.txt + DME1737 HARDWARE MONITOR DRIVER M: Juerg Haefliger L: linux-hwmon@vger.kernel.org diff --git a/drivers/memory/samsung/Kconfig b/drivers/memory/samsung/Kconfig index 79ce7ea58903..e9c3ce92350c 100644 --- a/drivers/memory/samsung/Kconfig +++ b/drivers/memory/samsung/Kconfig @@ -7,6 +7,19 @@ config SAMSUNG_MC if SAMSUNG_MC +config EXYNOS5422_DMC + tristate "EXYNOS5422 Dynamic Memory Controller driver" + depends on ARCH_EXYNOS || (COMPILE_TEST && HAS_IOMEM) + select DDR + depends on DEVFREQ_GOV_SIMPLE_ONDEMAND + depends on (PM_DEVFREQ && PM_DEVFREQ_EVENT) + help + This adds driver for Exynos5422 DMC (Dynamic Memory Controller). + The driver provides support for Dynamic Voltage and Frequency Scaling in + DMC and DRAM. It also supports changing timings of DRAM running with + different frequency. The timings are calculated based on DT memory + information. + config EXYNOS_SROM bool "Exynos SROM controller driver" if COMPILE_TEST depends on (ARM && ARCH_EXYNOS) || (COMPILE_TEST && HAS_IOMEM) diff --git a/drivers/memory/samsung/Makefile b/drivers/memory/samsung/Makefile index 00587be66211..ea071be21c44 100644 --- a/drivers/memory/samsung/Makefile +++ b/drivers/memory/samsung/Makefile @@ -1,2 +1,3 @@ # SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_EXYNOS5422_DMC) += exynos5422-dmc.o obj-$(CONFIG_EXYNOS_SROM) += exynos-srom.o diff --git a/drivers/memory/samsung/exynos5422-dmc.c b/drivers/memory/samsung/exynos5422-dmc.c new file mode 100644 index 000000000000..8c2ec29a7d57 --- /dev/null +++ b/drivers/memory/samsung/exynos5422-dmc.c @@ -0,0 +1,1257 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2019 Samsung Electronics Co., Ltd. + * Author: Lukasz Luba + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "../jedec_ddr.h" +#include "../of_memory.h" + +#define EXYNOS5_DREXI_TIMINGAREF (0x0030) +#define EXYNOS5_DREXI_TIMINGROW0 (0x0034) +#define EXYNOS5_DREXI_TIMINGDATA0 (0x0038) +#define EXYNOS5_DREXI_TIMINGPOWER0 (0x003C) +#define EXYNOS5_DREXI_TIMINGROW1 (0x00E4) +#define EXYNOS5_DREXI_TIMINGDATA1 (0x00E8) +#define EXYNOS5_DREXI_TIMINGPOWER1 (0x00EC) +#define CDREX_PAUSE (0x2091c) +#define CDREX_LPDDR3PHY_CON3 (0x20a20) +#define CDREX_LPDDR3PHY_CLKM_SRC (0x20700) +#define EXYNOS5_TIMING_SET_SWI BIT(28) +#define USE_MX_MSPLL_TIMINGS (1) +#define USE_BPLL_TIMINGS (0) +#define EXYNOS5_AREF_NORMAL (0x2e) + +/** + * struct dmc_opp_table - Operating level desciption + * + * Covers frequency and voltage settings of the DMC operating mode. + */ +struct dmc_opp_table { + u32 freq_hz; + u32 volt_uv; +}; + +/** + * struct exynos5_dmc - main structure describing DMC device + * + * The main structure for the Dynamic Memory Controller which covers clocks, + * memory regions, HW information, parameters and current operating mode. + */ +struct exynos5_dmc { + struct device *dev; + struct devfreq *df; + struct devfreq_simple_ondemand_data gov_data; + void __iomem *base_drexi0; + void __iomem *base_drexi1; + struct regmap *clk_regmap; + struct mutex lock; + unsigned long curr_rate; + unsigned long curr_volt; + unsigned long bypass_rate; + struct dmc_opp_table *opp; + struct dmc_opp_table opp_bypass; + int opp_count; + u32 timings_arr_size; + u32 *timing_row; + u32 *timing_data; + u32 *timing_power; + const struct lpddr3_timings *timings; + const struct lpddr3_min_tck *min_tck; + u32 bypass_timing_row; + u32 bypass_timing_data; + u32 bypass_timing_power; + struct regulator *vdd_mif; + struct clk *fout_spll; + struct clk *fout_bpll; + struct clk *mout_spll; + struct clk *mout_bpll; + struct clk *mout_mclk_cdrex; + struct clk *mout_mx_mspll_ccore; + struct clk *mx_mspll_ccore_phy; + struct clk *mout_mx_mspll_ccore_phy; + struct devfreq_event_dev **counter; + int num_counters; +}; + +#define TIMING_FIELD(t_name, t_bit_beg, t_bit_end) \ + { .name = t_name, .bit_beg = t_bit_beg, .bit_end = t_bit_end } + +#define TIMING_VAL2REG(timing, t_val) \ +({ \ + u32 __val; \ + __val = (t_val) << (timing)->bit_beg; \ + __val; \ +}) + +struct timing_reg { + char *name; + int bit_beg; + int bit_end; + unsigned int val; +}; + +static const struct timing_reg timing_row[] = { + TIMING_FIELD("tRFC", 24, 31), + TIMING_FIELD("tRRD", 20, 23), + TIMING_FIELD("tRP", 16, 19), + TIMING_FIELD("tRCD", 12, 15), + TIMING_FIELD("tRC", 6, 11), + TIMING_FIELD("tRAS", 0, 5), +}; + +static const struct timing_reg timing_data[] = { + TIMING_FIELD("tWTR", 28, 31), + TIMING_FIELD("tWR", 24, 27), + TIMING_FIELD("tRTP", 20, 23), + TIMING_FIELD("tW2W-C2C", 14, 14), + TIMING_FIELD("tR2R-C2C", 12, 12), + TIMING_FIELD("WL", 8, 11), + TIMING_FIELD("tDQSCK", 4, 7), + TIMING_FIELD("RL", 0, 3), +}; + +static const struct timing_reg timing_power[] = { + TIMING_FIELD("tFAW", 26, 31), + TIMING_FIELD("tXSR", 16, 25), + TIMING_FIELD("tXP", 8, 15), + TIMING_FIELD("tCKE", 4, 7), + TIMING_FIELD("tMRD", 0, 3), +}; + +#define TIMING_COUNT (ARRAY_SIZE(timing_row) + ARRAY_SIZE(timing_data) + \ + ARRAY_SIZE(timing_power)) + +static int exynos5_counters_set_event(struct exynos5_dmc *dmc) +{ + int i, ret; + + for (i = 0; i < dmc->num_counters; i++) { + if (!dmc->counter[i]) + continue; + ret = devfreq_event_set_event(dmc->counter[i]); + if (ret < 0) + return ret; + } + return 0; +} + +static int exynos5_counters_enable_edev(struct exynos5_dmc *dmc) +{ + int i, ret; + + for (i = 0; i < dmc->num_counters; i++) { + if (!dmc->counter[i]) + continue; + ret = devfreq_event_enable_edev(dmc->counter[i]); + if (ret < 0) + return ret; + } + return 0; +} + +static int exynos5_counters_disable_edev(struct exynos5_dmc *dmc) +{ + int i, ret; + + for (i = 0; i < dmc->num_counters; i++) { + if (!dmc->counter[i]) + continue; + ret = devfreq_event_disable_edev(dmc->counter[i]); + if (ret < 0) + return ret; + } + return 0; +} + +/** + * find_target_freq_id() - Finds requested frequency in local DMC configuration + * @dmc: device for which the information is checked + * @target_rate: requested frequency in KHz + * + * Seeks in the local DMC driver structure for the requested frequency value + * and returns index or error value. + */ +static int find_target_freq_idx(struct exynos5_dmc *dmc, + unsigned long target_rate) +{ + int i; + + for (i = dmc->opp_count - 1; i >= 0; i--) + if (dmc->opp[i].freq_hz <= target_rate) + return i; + + return -EINVAL; +} + +/** + * exynos5_switch_timing_regs() - Changes bank register set for DRAM timings + * @dmc: device for which the new settings is going to be applied + * @set: boolean variable passing set value + * + * Changes the register set, which holds timing parameters. + * There is two register sets: 0 and 1. The register set 0 + * is used in normal operation when the clock is provided from main PLL. + * The bank register set 1 is used when the main PLL frequency is going to be + * changed and the clock is taken from alternative, stable source. + * This function switches between these banks according to the + * currently used clock source. + */ +static void exynos5_switch_timing_regs(struct exynos5_dmc *dmc, bool set) +{ + unsigned int reg; + int ret; + + ret = regmap_read(dmc->clk_regmap, CDREX_LPDDR3PHY_CON3, ®); + + if (set) + reg |= EXYNOS5_TIMING_SET_SWI; + else + reg &= ~EXYNOS5_TIMING_SET_SWI; + + regmap_write(dmc->clk_regmap, CDREX_LPDDR3PHY_CON3, reg); +} + +/** + * exynos5_init_freq_table() - Initialized PM OPP framework + * @dmc: DMC device for which the frequencies are used for OPP init + * @profile: devfreq device's profile + * + * Populate the devfreq device's OPP table based on current frequency, voltage. + */ +static int exynos5_init_freq_table(struct exynos5_dmc *dmc, + struct devfreq_dev_profile *profile) +{ + int i, ret; + int idx; + unsigned long freq; + + ret = dev_pm_opp_of_add_table(dmc->dev); + if (ret < 0) { + dev_err(dmc->dev, "Failed to get OPP table\n"); + return ret; + } + + dmc->opp_count = dev_pm_opp_get_opp_count(dmc->dev); + + dmc->opp = devm_kmalloc_array(dmc->dev, dmc->opp_count, + sizeof(struct dmc_opp_table), GFP_KERNEL); + if (!dmc->opp) + goto err_opp; + + idx = dmc->opp_count - 1; + for (i = 0, freq = ULONG_MAX; i < dmc->opp_count; i++, freq--) { + struct dev_pm_opp *opp; + + opp = dev_pm_opp_find_freq_floor(dmc->dev, &freq); + if (IS_ERR(opp)) + goto err_free_tables; + + dmc->opp[idx - i].freq_hz = freq; + dmc->opp[idx - i].volt_uv = dev_pm_opp_get_voltage(opp); + + dev_pm_opp_put(opp); + } + + return 0; + +err_free_tables: + kfree(dmc->opp); +err_opp: + dev_pm_opp_of_remove_table(dmc->dev); + + return -EINVAL; +} + +/** + * exynos5_set_bypass_dram_timings() - Low-level changes of the DRAM timings + * @dmc: device for which the new settings is going to be applied + * @param: DRAM parameters which passes timing data + * + * Low-level function for changing timings for DRAM memory clocking from + * 'bypass' clock source (fixed frequency @400MHz). + * It uses timing bank registers set 1. + */ +static void exynos5_set_bypass_dram_timings(struct exynos5_dmc *dmc) +{ + writel(EXYNOS5_AREF_NORMAL, + dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGAREF); + + writel(dmc->bypass_timing_row, + dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGROW1); + writel(dmc->bypass_timing_row, + dmc->base_drexi1 + EXYNOS5_DREXI_TIMINGROW1); + writel(dmc->bypass_timing_data, + dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGDATA1); + writel(dmc->bypass_timing_data, + dmc->base_drexi1 + EXYNOS5_DREXI_TIMINGDATA1); + writel(dmc->bypass_timing_power, + dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGPOWER1); + writel(dmc->bypass_timing_power, + dmc->base_drexi1 + EXYNOS5_DREXI_TIMINGPOWER1); +} + +/** + * exynos5_dram_change_timings() - Low-level changes of the DRAM final timings + * @dmc: device for which the new settings is going to be applied + * @target_rate: target frequency of the DMC + * + * Low-level function for changing timings for DRAM memory operating from main + * clock source (BPLL), which can have different frequencies. Thus, each + * frequency must have corresponding timings register values in order to keep + * the needed delays. + * It uses timing bank registers set 0. + */ +static int exynos5_dram_change_timings(struct exynos5_dmc *dmc, + unsigned long target_rate) +{ + int idx; + + for (idx = dmc->opp_count - 1; idx >= 0; idx--) + if (dmc->opp[idx].freq_hz <= target_rate) + break; + + if (idx < 0) + return -EINVAL; + + writel(EXYNOS5_AREF_NORMAL, + dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGAREF); + + writel(dmc->timing_row[idx], + dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGROW0); + writel(dmc->timing_row[idx], + dmc->base_drexi1 + EXYNOS5_DREXI_TIMINGROW0); + writel(dmc->timing_data[idx], + dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGDATA0); + writel(dmc->timing_data[idx], + dmc->base_drexi1 + EXYNOS5_DREXI_TIMINGDATA0); + writel(dmc->timing_power[idx], + dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGPOWER0); + writel(dmc->timing_power[idx], + dmc->base_drexi1 + EXYNOS5_DREXI_TIMINGPOWER0); + + return 0; +} + +/** + * exynos5_dmc_align_target_voltage() - Sets the final voltage for the DMC + * @dmc: device for which it is going to be set + * @target_volt: new voltage which is chosen to be final + * + * Function tries to align voltage to the safe level for 'normal' mode. + * It checks the need of higher voltage and changes the value. The target + * voltage might be lower that currently set and still the system will be + * stable. + */ +static int exynos5_dmc_align_target_voltage(struct exynos5_dmc *dmc, + unsigned long target_volt) +{ + int ret = 0; + + if (dmc->curr_volt <= target_volt) + return 0; + + ret = regulator_set_voltage(dmc->vdd_mif, target_volt, + target_volt); + if (!ret) + dmc->curr_volt = target_volt; + + return ret; +} + +/** + * exynos5_dmc_align_bypass_voltage() - Sets the voltage for the DMC + * @dmc: device for which it is going to be set + * @target_volt: new voltage which is chosen to be final + * + * Function tries to align voltage to the safe level for the 'bypass' mode. + * It checks the need of higher voltage and changes the value. + * The target voltage must not be less than currently needed, because + * for current frequency the device might become unstable. + */ +static int exynos5_dmc_align_bypass_voltage(struct exynos5_dmc *dmc, + unsigned long target_volt) +{ + int ret = 0; + unsigned long bypass_volt = dmc->opp_bypass.volt_uv; + + target_volt = max(bypass_volt, target_volt); + + if (dmc->curr_volt >= target_volt) + return 0; + + ret = regulator_set_voltage(dmc->vdd_mif, target_volt, + target_volt); + if (!ret) + dmc->curr_volt = target_volt; + + return ret; +} + +/** + * exynos5_dmc_align_bypass_dram_timings() - Chooses and sets DRAM timings + * @dmc: device for which it is going to be set + * @target_rate: new frequency which is chosen to be final + * + * Function changes the DRAM timings for the temporary 'bypass' mode. + */ +static int exynos5_dmc_align_bypass_dram_timings(struct exynos5_dmc *dmc, + unsigned long target_rate) +{ + int idx = find_target_freq_idx(dmc, target_rate); + + if (idx < 0) + return -EINVAL; + + exynos5_set_bypass_dram_timings(dmc); + + return 0; +} + +/** + * exynos5_dmc_switch_to_bypass_configuration() - Switching to temporary clock + * @dmc: DMC device for which the switching is going to happen + * @target_rate: new frequency which is going to be set as a final + * @target_volt: new voltage which is going to be set as a final + * + * Function configures DMC and clocks for operating in temporary 'bypass' mode. + * This mode is used only temporary but if required, changes voltage and timings + * for DRAM chips. It switches the main clock to stable clock source for the + * period of the main PLL reconfiguration. + */ +static int +exynos5_dmc_switch_to_bypass_configuration(struct exynos5_dmc *dmc, + unsigned long target_rate, + unsigned long target_volt) +{ + int ret; + + /* + * Having higher voltage for a particular frequency does not harm + * the chip. Use it for the temporary frequency change when one + * voltage manipulation might be avoided. + */ + ret = exynos5_dmc_align_bypass_voltage(dmc, target_volt); + if (ret) + return ret; + + /* + * Longer delays for DRAM does not cause crash, the opposite does. + */ + ret = exynos5_dmc_align_bypass_dram_timings(dmc, target_rate); + if (ret) + return ret; + + /* + * Delays are long enough, so use them for the new coming clock. + */ + exynos5_switch_timing_regs(dmc, USE_MX_MSPLL_TIMINGS); + + return ret; +} + +/** + * exynos5_dmc_change_freq_and_volt() - Changes voltage and frequency of the DMC + * using safe procedure + * @dmc: device for which the frequency is going to be changed + * @target_rate: requested new frequency + * @target_volt: requested voltage which corresponds to the new frequency + * + * The DMC frequency change procedure requires a few steps. + * The main requirement is to change the clock source in the clk mux + * for the time of main clock PLL locking. The assumption is that the + * alternative clock source set as parent is stable. + * The second parent's clock frequency is fixed to 400MHz, it is named 'bypass' + * clock. This requires alignment in DRAM timing parameters for the new + * T-period. There is two bank sets for keeping DRAM + * timings: set 0 and set 1. The set 0 is used when main clock source is + * chosen. The 2nd set of regs is used for 'bypass' clock. Switching between + * the two bank sets is part of the process. + * The voltage must also be aligned to the minimum required level. There is + * this intermediate step with switching to 'bypass' parent clock source. + * if the old voltage is lower, it requires an increase of the voltage level. + * The complexity of the voltage manipulation is hidden in low level function. + * In this function there is last alignment of the voltage level at the end. + */ +static int +exynos5_dmc_change_freq_and_volt(struct exynos5_dmc *dmc, + unsigned long target_rate, + unsigned long target_volt) +{ + int ret; + + ret = exynos5_dmc_switch_to_bypass_configuration(dmc, target_rate, + target_volt); + if (ret) + return ret; + + /* + * Voltage is set at least to a level needed for this frequency, + * so switching clock source is safe now. + */ + clk_prepare_enable(dmc->fout_spll); + clk_prepare_enable(dmc->mout_spll); + clk_prepare_enable(dmc->mout_mx_mspll_ccore); + + ret = clk_set_parent(dmc->mout_mclk_cdrex, dmc->mout_mx_mspll_ccore); + if (ret) + goto disable_clocks; + + /* + * We are safe to increase the timings for current bypass frequency. + * Thanks to this the settings will be ready for the upcoming clock + * source change. + */ + exynos5_dram_change_timings(dmc, target_rate); + + clk_set_rate(dmc->fout_bpll, target_rate); + + exynos5_switch_timing_regs(dmc, USE_BPLL_TIMINGS); + + ret = clk_set_parent(dmc->mout_mclk_cdrex, dmc->mout_bpll); + if (ret) + goto disable_clocks; + + /* + * Make sure if the voltage is not from 'bypass' settings and align to + * the right level for power efficiency. + */ + ret = exynos5_dmc_align_target_voltage(dmc, target_volt); + +disable_clocks: + clk_disable_unprepare(dmc->mout_mx_mspll_ccore); + clk_disable_unprepare(dmc->mout_spll); + clk_disable_unprepare(dmc->fout_spll); + + return ret; +} + +/** + * exynos5_dmc_get_volt_freq() - Gets the frequency and voltage from the OPP + * table. + * @dmc: device for which the frequency is going to be changed + * @freq: requested frequency in KHz + * @target_rate: returned frequency which is the same or lower than + * requested + * @target_volt: returned voltage which corresponds to the returned + * frequency + * + * Function gets requested frequency and checks OPP framework for needed + * frequency and voltage. It populates the values 'target_rate' and + * 'target_volt' or returns error value when OPP framework fails. + */ +static int exynos5_dmc_get_volt_freq(struct exynos5_dmc *dmc, + unsigned long *freq, + unsigned long *target_rate, + unsigned long *target_volt, u32 flags) +{ + struct dev_pm_opp *opp; + + opp = devfreq_recommended_opp(dmc->dev, freq, flags); + if (IS_ERR(opp)) + return PTR_ERR(opp); + + *target_rate = dev_pm_opp_get_freq(opp); + *target_volt = dev_pm_opp_get_voltage(opp); + dev_pm_opp_put(opp); + + return 0; +} + +/** + * exynos5_dmc_target() - Function responsible for changing frequency of DMC + * @dev: device for which the frequency is going to be changed + * @freq: requested frequency in KHz + * @flags: flags provided for this frequency change request + * + * An entry function provided to the devfreq framework which provides frequency + * change of the DMC. The function gets the possible rate from OPP table based + * on requested frequency. It calls the next function responsible for the + * frequency and voltage change. In case of failure, does not set 'curr_rate' + * and returns error value to the framework. + */ +static int exynos5_dmc_target(struct device *dev, unsigned long *freq, + u32 flags) +{ + struct exynos5_dmc *dmc = dev_get_drvdata(dev); + unsigned long target_rate = 0; + unsigned long target_volt = 0; + int ret; + + ret = exynos5_dmc_get_volt_freq(dmc, freq, &target_rate, &target_volt, + flags); + + if (ret) + return ret; + + if (target_rate == dmc->curr_rate) + return 0; + + mutex_lock(&dmc->lock); + + ret = exynos5_dmc_change_freq_and_volt(dmc, target_rate, target_volt); + + if (ret) { + mutex_unlock(&dmc->lock); + return ret; + } + + dmc->curr_rate = target_rate; + + mutex_unlock(&dmc->lock); + return 0; +} + +/** + * exynos5_counters_get() - Gets the performance counters values. + * @dmc: device for which the counters are going to be checked + * @load_count: variable which is populated with counter value + * @total_count: variable which is used as 'wall clock' reference + * + * Function which provides performance counters values. It sums up counters for + * two DMC channels. The 'total_count' is used as a reference and max value. + * The ratio 'load_count/total_count' shows the busy percentage [0%, 100%]. + */ +static int exynos5_counters_get(struct exynos5_dmc *dmc, + unsigned long *load_count, + unsigned long *total_count) +{ + unsigned long total = 0; + struct devfreq_event_data event; + int ret, i; + + *load_count = 0; + + /* Take into account only read+write counters, but stop all */ + for (i = 0; i < dmc->num_counters; i++) { + if (!dmc->counter[i]) + continue; + + ret = devfreq_event_get_event(dmc->counter[i], &event); + if (ret < 0) + return ret; + + *load_count += event.load_count; + + if (total < event.total_count) + total = event.total_count; + } + + *total_count = total; + + return 0; +} + +/** + * exynos5_dmc_get_status() - Read current DMC performance statistics. + * @dev: device for which the statistics are requested + * @stat: structure which has statistic fields + * + * Function reads the DMC performance counters and calculates 'busy_time' + * and 'total_time'. To protect from overflow, the values are shifted right + * by 10. After read out the counters are setup to count again. + */ +static int exynos5_dmc_get_status(struct device *dev, + struct devfreq_dev_status *stat) +{ + struct exynos5_dmc *dmc = dev_get_drvdata(dev); + unsigned long load, total; + int ret; + + ret = exynos5_counters_get(dmc, &load, &total); + if (ret < 0) + return -EINVAL; + + /* To protect from overflow in calculation ratios, divide by 1024 */ + stat->busy_time = load >> 10; + stat->total_time = total >> 10; + + ret = exynos5_counters_set_event(dmc); + if (ret < 0) { + dev_err(dev, "could not set event counter\n"); + return ret; + } + + return 0; +} + +/** + * exynos5_dmc_get_cur_freq() - Function returns current DMC frequency + * @dev: device for which the framework checks operating frequency + * @freq: returned frequency value + * + * It returns the currently used frequency of the DMC. The real operating + * frequency might be lower when the clock source value could not be divided + * to the requested value. + */ +static int exynos5_dmc_get_cur_freq(struct device *dev, unsigned long *freq) +{ + struct exynos5_dmc *dmc = dev_get_drvdata(dev); + + mutex_lock(&dmc->lock); + *freq = dmc->curr_rate; + mutex_unlock(&dmc->lock); + + return 0; +} + +/** + * exynos5_dmc_df_profile - Devfreq governor's profile structure + * + * It provides to the devfreq framework needed functions and polling period. + */ +static struct devfreq_dev_profile exynos5_dmc_df_profile = { + .polling_ms = 500, + .target = exynos5_dmc_target, + .get_dev_status = exynos5_dmc_get_status, + .get_cur_freq = exynos5_dmc_get_cur_freq, +}; + +/** + * exynos5_dmc_align_initial_frequency() - Align initial frequency value + * @dmc: device for which the frequency is going to be set + * @bootloader_init_freq: initial frequency set by the bootloader in KHz + * + * The initial bootloader frequency, which is present during boot, might be + * different that supported frequency values in the driver. It is possible + * due to different PLL settings or used PLL as a source. + * This function provides the 'initial_freq' for the devfreq framework + * statistics engine which supports only registered values. Thus, some alignment + * must be made. + */ +unsigned long +exynos5_dmc_align_init_freq(struct exynos5_dmc *dmc, + unsigned long bootloader_init_freq) +{ + unsigned long aligned_freq; + int idx; + + idx = find_target_freq_idx(dmc, bootloader_init_freq); + if (idx >= 0) + aligned_freq = dmc->opp[idx].freq_hz; + else + aligned_freq = dmc->opp[dmc->opp_count - 1].freq_hz; + + return aligned_freq; +} + +/** + * create_timings_aligned() - Create register values and align with standard + * @dmc: device for which the frequency is going to be set + * @idx: speed bin in the OPP table + * @clk_period_ps: the period of the clock, known as tCK + * + * The function calculates timings and creates a register value ready for + * a frequency transition. The register contains a few timings. They are + * shifted by a known offset. The timing value is calculated based on memory + * specyfication: minimal time required and minimal cycles required. + */ +static int create_timings_aligned(struct exynos5_dmc *dmc, u32 *reg_timing_row, + u32 *reg_timing_data, u32 *reg_timing_power, + u32 clk_period_ps) +{ + u32 val; + const struct timing_reg *reg; + + if (clk_period_ps == 0) + return -EINVAL; + + *reg_timing_row = 0; + *reg_timing_data = 0; + *reg_timing_power = 0; + + val = dmc->timings->tRFC / clk_period_ps; + val += dmc->timings->tRFC % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tRFC); + reg = &timing_row[0]; + *reg_timing_row |= TIMING_VAL2REG(reg, val); + + val = dmc->timings->tRRD / clk_period_ps; + val += dmc->timings->tRRD % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tRRD); + reg = &timing_row[1]; + *reg_timing_row |= TIMING_VAL2REG(reg, val); + + val = dmc->timings->tRPab / clk_period_ps; + val += dmc->timings->tRPab % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tRPab); + reg = &timing_row[2]; + *reg_timing_row |= TIMING_VAL2REG(reg, val); + + val = dmc->timings->tRCD / clk_period_ps; + val += dmc->timings->tRCD % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tRCD); + reg = &timing_row[3]; + *reg_timing_row |= TIMING_VAL2REG(reg, val); + + val = dmc->timings->tRC / clk_period_ps; + val += dmc->timings->tRC % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tRC); + reg = &timing_row[4]; + *reg_timing_row |= TIMING_VAL2REG(reg, val); + + val = dmc->timings->tRAS / clk_period_ps; + val += dmc->timings->tRAS % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tRAS); + reg = &timing_row[5]; + *reg_timing_row |= TIMING_VAL2REG(reg, val); + + /* data related timings */ + val = dmc->timings->tWTR / clk_period_ps; + val += dmc->timings->tWTR % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tWTR); + reg = &timing_data[0]; + *reg_timing_data |= TIMING_VAL2REG(reg, val); + + val = dmc->timings->tWR / clk_period_ps; + val += dmc->timings->tWR % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tWR); + reg = &timing_data[1]; + *reg_timing_data |= TIMING_VAL2REG(reg, val); + + val = dmc->timings->tRTP / clk_period_ps; + val += dmc->timings->tRTP % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tRTP); + reg = &timing_data[2]; + *reg_timing_data |= TIMING_VAL2REG(reg, val); + + val = dmc->timings->tW2W_C2C / clk_period_ps; + val += dmc->timings->tW2W_C2C % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tW2W_C2C); + reg = &timing_data[3]; + *reg_timing_data |= TIMING_VAL2REG(reg, val); + + val = dmc->timings->tR2R_C2C / clk_period_ps; + val += dmc->timings->tR2R_C2C % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tR2R_C2C); + reg = &timing_data[4]; + *reg_timing_data |= TIMING_VAL2REG(reg, val); + + val = dmc->timings->tWL / clk_period_ps; + val += dmc->timings->tWL % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tWL); + reg = &timing_data[5]; + *reg_timing_data |= TIMING_VAL2REG(reg, val); + + val = dmc->timings->tDQSCK / clk_period_ps; + val += dmc->timings->tDQSCK % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tDQSCK); + reg = &timing_data[6]; + *reg_timing_data |= TIMING_VAL2REG(reg, val); + + val = dmc->timings->tRL / clk_period_ps; + val += dmc->timings->tRL % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tRL); + reg = &timing_data[7]; + *reg_timing_data |= TIMING_VAL2REG(reg, val); + + /* power related timings */ + val = dmc->timings->tFAW / clk_period_ps; + val += dmc->timings->tFAW % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tXP); + reg = &timing_power[0]; + *reg_timing_power |= TIMING_VAL2REG(reg, val); + + val = dmc->timings->tXSR / clk_period_ps; + val += dmc->timings->tXSR % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tXSR); + reg = &timing_power[1]; + *reg_timing_power |= TIMING_VAL2REG(reg, val); + + val = dmc->timings->tXP / clk_period_ps; + val += dmc->timings->tXP % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tXP); + reg = &timing_power[2]; + *reg_timing_power |= TIMING_VAL2REG(reg, val); + + val = dmc->timings->tCKE / clk_period_ps; + val += dmc->timings->tCKE % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tCKE); + reg = &timing_power[3]; + *reg_timing_power |= TIMING_VAL2REG(reg, val); + + val = dmc->timings->tMRD / clk_period_ps; + val += dmc->timings->tMRD % clk_period_ps ? 1 : 0; + val = max(val, dmc->min_tck->tMRD); + reg = &timing_power[4]; + *reg_timing_power |= TIMING_VAL2REG(reg, val); + + return 0; +} + +/** + * of_get_dram_timings() - helper function for parsing DT settings for DRAM + * @dmc: device for which the frequency is going to be set + * + * The function parses DT entries with DRAM information. + */ +static int of_get_dram_timings(struct exynos5_dmc *dmc) +{ + int ret = 0; + int idx; + struct device_node *np_ddr; + u32 freq_mhz, clk_period_ps; + + np_ddr = of_parse_phandle(dmc->dev->of_node, "device-handle", 0); + if (!np_ddr) { + dev_warn(dmc->dev, "could not find 'device-handle' in DT\n"); + return -EINVAL; + } + + dmc->timing_row = devm_kmalloc_array(dmc->dev, TIMING_COUNT, + sizeof(u32), GFP_KERNEL); + if (!dmc->timing_row) + return -ENOMEM; + + dmc->timing_data = devm_kmalloc_array(dmc->dev, TIMING_COUNT, + sizeof(u32), GFP_KERNEL); + if (!dmc->timing_data) + return -ENOMEM; + + dmc->timing_power = devm_kmalloc_array(dmc->dev, TIMING_COUNT, + sizeof(u32), GFP_KERNEL); + if (!dmc->timing_power) + return -ENOMEM; + + dmc->timings = of_lpddr3_get_ddr_timings(np_ddr, dmc->dev, + DDR_TYPE_LPDDR3, + &dmc->timings_arr_size); + if (!dmc->timings) { + of_node_put(np_ddr); + dev_warn(dmc->dev, "could not get timings from DT\n"); + return -EINVAL; + } + + dmc->min_tck = of_lpddr3_get_min_tck(np_ddr, dmc->dev); + if (!dmc->min_tck) { + of_node_put(np_ddr); + dev_warn(dmc->dev, "could not get tck from DT\n"); + return -EINVAL; + } + + /* Sorted array of OPPs with frequency ascending */ + for (idx = 0; idx < dmc->opp_count; idx++) { + freq_mhz = dmc->opp[idx].freq_hz / 1000000; + clk_period_ps = 1000000 / freq_mhz; + + ret = create_timings_aligned(dmc, &dmc->timing_row[idx], + &dmc->timing_data[idx], + &dmc->timing_power[idx], + clk_period_ps); + } + + of_node_put(np_ddr); + + /* Take the highest frequency's timings as 'bypass' */ + dmc->bypass_timing_row = dmc->timing_row[idx - 1]; + dmc->bypass_timing_data = dmc->timing_data[idx - 1]; + dmc->bypass_timing_power = dmc->timing_power[idx - 1]; + + return ret; +} + +/** + * exynos5_dmc_init_clks() - Initialize clocks needed for DMC operation. + * @dmc: DMC structure containing needed fields + * + * Get the needed clocks defined in DT device, enable and set the right parents. + * Read current frequency and initialize the initial rate for governor. + */ +static int exynos5_dmc_init_clks(struct exynos5_dmc *dmc) +{ + int ret; + unsigned long target_volt = 0; + unsigned long target_rate = 0; + unsigned int tmp; + + dmc->fout_spll = devm_clk_get(dmc->dev, "fout_spll"); + if (IS_ERR(dmc->fout_spll)) + return PTR_ERR(dmc->fout_spll); + + dmc->fout_bpll = devm_clk_get(dmc->dev, "fout_bpll"); + if (IS_ERR(dmc->fout_bpll)) + return PTR_ERR(dmc->fout_bpll); + + dmc->mout_mclk_cdrex = devm_clk_get(dmc->dev, "mout_mclk_cdrex"); + if (IS_ERR(dmc->mout_mclk_cdrex)) + return PTR_ERR(dmc->mout_mclk_cdrex); + + dmc->mout_bpll = devm_clk_get(dmc->dev, "mout_bpll"); + if (IS_ERR(dmc->mout_bpll)) + return PTR_ERR(dmc->mout_bpll); + + dmc->mout_mx_mspll_ccore = devm_clk_get(dmc->dev, + "mout_mx_mspll_ccore"); + if (IS_ERR(dmc->mout_mx_mspll_ccore)) + return PTR_ERR(dmc->mout_mx_mspll_ccore); + + dmc->mout_spll = devm_clk_get(dmc->dev, "ff_dout_spll2"); + if (IS_ERR(dmc->mout_spll)) { + dmc->mout_spll = devm_clk_get(dmc->dev, "mout_sclk_spll"); + if (IS_ERR(dmc->mout_spll)) + return PTR_ERR(dmc->mout_spll); + } + + /* + * Convert frequency to KHz values and set it for the governor. + */ + dmc->curr_rate = clk_get_rate(dmc->mout_mclk_cdrex); + dmc->curr_rate = exynos5_dmc_align_init_freq(dmc, dmc->curr_rate); + exynos5_dmc_df_profile.initial_freq = dmc->curr_rate; + + ret = exynos5_dmc_get_volt_freq(dmc, &dmc->curr_rate, &target_rate, + &target_volt, 0); + if (ret) + return ret; + + dmc->curr_volt = target_volt; + + clk_set_parent(dmc->mout_mx_mspll_ccore, dmc->mout_spll); + + dmc->bypass_rate = clk_get_rate(dmc->mout_mx_mspll_ccore); + + clk_prepare_enable(dmc->fout_bpll); + clk_prepare_enable(dmc->mout_bpll); + + /* + * Some bootloaders do not set clock routes correctly. + * Stop one path in clocks to PHY. + */ + regmap_read(dmc->clk_regmap, CDREX_LPDDR3PHY_CLKM_SRC, &tmp); + tmp &= ~(BIT(1) | BIT(0)); + regmap_write(dmc->clk_regmap, CDREX_LPDDR3PHY_CLKM_SRC, tmp); + + return 0; +} + +/** + * exynos5_performance_counters_init() - Initializes performance DMC's counters + * @dmc: DMC for which it does the setup + * + * Initialization of performance counters in DMC for estimating usage. + * The counter's values are used for calculation of a memory bandwidth and based + * on that the governor changes the frequency. + * The counters are not used when the governor is GOVERNOR_USERSPACE. + */ +static int exynos5_performance_counters_init(struct exynos5_dmc *dmc) +{ + int counters_size; + int ret, i; + + dmc->num_counters = devfreq_event_get_edev_count(dmc->dev); + if (dmc->num_counters < 0) { + dev_err(dmc->dev, "could not get devfreq-event counters\n"); + return dmc->num_counters; + } + + counters_size = sizeof(struct devfreq_event_dev) * dmc->num_counters; + dmc->counter = devm_kzalloc(dmc->dev, counters_size, GFP_KERNEL); + if (!dmc->counter) + return -ENOMEM; + + for (i = 0; i < dmc->num_counters; i++) { + dmc->counter[i] = + devfreq_event_get_edev_by_phandle(dmc->dev, i); + if (IS_ERR_OR_NULL(dmc->counter[i])) + return -EPROBE_DEFER; + } + + ret = exynos5_counters_enable_edev(dmc); + if (ret < 0) { + dev_err(dmc->dev, "could not enable event counter\n"); + return ret; + } + + ret = exynos5_counters_set_event(dmc); + if (ret < 0) { + exynos5_counters_disable_edev(dmc); + dev_err(dmc->dev, "counld not set event counter\n"); + return ret; + } + + return 0; +} + +/** + * exynos5_dmc_set_pause_on_switching() - Controls a pause feature in DMC + * @dmc: device which is used for changing this feature + * @set: a boolean state passing enable/disable request + * + * There is a need of pausing DREX DMC when divider or MUX in clock tree + * changes its configuration. In such situation access to the memory is blocked + * in DMC automatically. This feature is used when clock frequency change + * request appears and touches clock tree. + */ +static inline int exynos5_dmc_set_pause_on_switching(struct exynos5_dmc *dmc) +{ + unsigned int val; + int ret; + + ret = regmap_read(dmc->clk_regmap, CDREX_PAUSE, &val); + if (ret) + return ret; + + val |= 1UL; + regmap_write(dmc->clk_regmap, CDREX_PAUSE, val); + + return 0; +} + +/** + * exynos5_dmc_probe() - Probe function for the DMC driver + * @pdev: platform device for which the driver is going to be initialized + * + * Initialize basic components: clocks, regulators, performance counters, etc. + * Read out product version and based on the information setup + * internal structures for the controller (frequency and voltage) and for DRAM + * memory parameters: timings for each operating frequency. + * Register new devfreq device for controlling DVFS of the DMC. + */ +static int exynos5_dmc_probe(struct platform_device *pdev) +{ + int ret = 0; + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct exynos5_dmc *dmc; + struct resource *res; + + dmc = devm_kzalloc(dev, sizeof(*dmc), GFP_KERNEL); + if (!dmc) + return -ENOMEM; + + mutex_init(&dmc->lock); + + dmc->dev = dev; + platform_set_drvdata(pdev, dmc); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + dmc->base_drexi0 = devm_ioremap_resource(dev, res); + if (IS_ERR(dmc->base_drexi0)) + return PTR_ERR(dmc->base_drexi0); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); + dmc->base_drexi1 = devm_ioremap_resource(dev, res); + if (IS_ERR(dmc->base_drexi1)) + return PTR_ERR(dmc->base_drexi1); + + dmc->clk_regmap = syscon_regmap_lookup_by_phandle(np, + "samsung,syscon-clk"); + if (IS_ERR(dmc->clk_regmap)) + return PTR_ERR(dmc->clk_regmap); + + ret = exynos5_init_freq_table(dmc, &exynos5_dmc_df_profile); + if (ret) { + dev_warn(dev, "couldn't initialize frequency settings\n"); + return ret; + } + + dmc->vdd_mif = devm_regulator_get(dev, "vdd"); + if (IS_ERR(dmc->vdd_mif)) { + ret = PTR_ERR(dmc->vdd_mif); + return ret; + } + + ret = exynos5_dmc_init_clks(dmc); + if (ret) + return ret; + + ret = of_get_dram_timings(dmc); + if (ret) { + dev_warn(dev, "couldn't initialize timings settings\n"); + goto remove_clocks; + } + + ret = exynos5_performance_counters_init(dmc); + if (ret) { + dev_warn(dev, "couldn't probe performance counters\n"); + goto remove_clocks; + } + + ret = exynos5_dmc_set_pause_on_switching(dmc); + if (ret) { + dev_warn(dev, "couldn't get access to PAUSE register\n"); + goto err_devfreq_add; + } + + /* + * Setup default thresholds for the devfreq governor. + * The values are chosen based on experiments. + */ + dmc->gov_data.upthreshold = 30; + dmc->gov_data.downdifferential = 5; + + dmc->df = devm_devfreq_add_device(dev, &exynos5_dmc_df_profile, + DEVFREQ_GOV_SIMPLE_ONDEMAND, + &dmc->gov_data); + + if (IS_ERR(dmc->df)) { + ret = PTR_ERR(dmc->df); + goto err_devfreq_add; + } + + dev_info(dev, "DMC initialized\n"); + + return 0; + +err_devfreq_add: + exynos5_counters_disable_edev(dmc); +remove_clocks: + clk_disable_unprepare(dmc->mout_bpll); + clk_disable_unprepare(dmc->fout_bpll); + + return ret; +} + +/** + * exynos5_dmc_remove() - Remove function for the platform device + * @pdev: platform device which is going to be removed + * + * The function relies on 'devm' framework function which automatically + * clean the device's resources. It just calls explicitly disable function for + * the performance counters. + */ +static int exynos5_dmc_remove(struct platform_device *pdev) +{ + struct exynos5_dmc *dmc = dev_get_drvdata(&pdev->dev); + + exynos5_counters_disable_edev(dmc); + + clk_disable_unprepare(dmc->mout_bpll); + clk_disable_unprepare(dmc->fout_bpll); + + dev_pm_opp_remove_table(dmc->dev); + + return 0; +} + +static const struct of_device_id exynos5_dmc_of_match[] = { + { .compatible = "samsung,exynos5422-dmc", }, + { }, +}; +MODULE_DEVICE_TABLE(of, exynos5_dmc_of_match); + +static struct platform_driver exynos5_dmc_platdrv = { + .probe = exynos5_dmc_probe, + .remove = exynos5_dmc_remove, + .driver = { + .name = "exynos5-dmc", + .of_match_table = exynos5_dmc_of_match, + }, +}; +module_platform_driver(exynos5_dmc_platdrv); +MODULE_DESCRIPTION("Driver for Exynos5422 Dynamic Memory Controller dynamic frequency and voltage change"); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Lukasz Luba"); From 7a5a687ec3e93d3e20d4705507f0648d054b1a9e Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Mon, 16 Sep 2019 10:12:49 +0100 Subject: [PATCH 3/5] memory: samsung: exynos5422-dmc: Fix spelling mistake "counld" -> "could" There is a spelling mistake in a dev_err message. Fix it. Signed-off-by: Colin Ian King Signed-off-by: Krzysztof Kozlowski --- drivers/memory/samsung/exynos5422-dmc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/memory/samsung/exynos5422-dmc.c b/drivers/memory/samsung/exynos5422-dmc.c index 8c2ec29a7d57..ac5f55813900 100644 --- a/drivers/memory/samsung/exynos5422-dmc.c +++ b/drivers/memory/samsung/exynos5422-dmc.c @@ -1078,7 +1078,7 @@ static int exynos5_performance_counters_init(struct exynos5_dmc *dmc) ret = exynos5_counters_set_event(dmc); if (ret < 0) { exynos5_counters_disable_edev(dmc); - dev_err(dmc->dev, "counld not set event counter\n"); + dev_err(dmc->dev, "could not set event counter\n"); return ret; } From d51e6a69f4e9e81cf75bbfdccce60d47e31ad901 Mon Sep 17 00:00:00 2001 From: Lukasz Luba Date: Thu, 19 Sep 2019 11:26:40 +0200 Subject: [PATCH 4/5] memory: samsung: exynos5422-dmc: Fix kfree() of devm-allocated memory and missing static Fix issues captured by static checkers: use of kfree() on resource-managed memory and missing 'static' in the private function. Fixes Smatch warning: drivers/memory/samsung/exynos5422-dmc.c:272 exynos5_init_freq_table() warn: passing devm_ allocated variable to kfree. 'dmc->opp' Fixes Sparse warning: drivers/memory/samsung/exynos5422-dmc.c:736:1: warning: symbol 'exynos5_dmc_align_init_freq' was not declared. Reported-by: kbuild test robot Reported-by: Dan Carpenter Reported-by: Krzysztof Kozlowski Signed-off-by: Lukasz Luba Signed-off-by: Krzysztof Kozlowski --- drivers/memory/samsung/exynos5422-dmc.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/memory/samsung/exynos5422-dmc.c b/drivers/memory/samsung/exynos5422-dmc.c index ac5f55813900..0fe5f2186139 100644 --- a/drivers/memory/samsung/exynos5422-dmc.c +++ b/drivers/memory/samsung/exynos5422-dmc.c @@ -258,7 +258,7 @@ static int exynos5_init_freq_table(struct exynos5_dmc *dmc, opp = dev_pm_opp_find_freq_floor(dmc->dev, &freq); if (IS_ERR(opp)) - goto err_free_tables; + goto err_opp; dmc->opp[idx - i].freq_hz = freq; dmc->opp[idx - i].volt_uv = dev_pm_opp_get_voltage(opp); @@ -268,8 +268,6 @@ static int exynos5_init_freq_table(struct exynos5_dmc *dmc, return 0; -err_free_tables: - kfree(dmc->opp); err_opp: dev_pm_opp_of_remove_table(dmc->dev); @@ -732,7 +730,7 @@ static struct devfreq_dev_profile exynos5_dmc_df_profile = { * statistics engine which supports only registered values. Thus, some alignment * must be made. */ -unsigned long +static unsigned long exynos5_dmc_align_init_freq(struct exynos5_dmc *dmc, unsigned long bootloader_init_freq) { From bbf918863e183d66adf00ca1b24fb641149a0d3d Mon Sep 17 00:00:00 2001 From: Lukasz Luba Date: Wed, 2 Oct 2019 08:04:55 +0200 Subject: [PATCH 5/5] memory: samsung: exynos5422-dmc: Add support for interrupt from performance counters Introduce a new interrupt driven mechanism for managing speed of the memory controller. The interrupts are generated due to performance counters overflow. The performance counters might track memory reads, writes, transfers, page misses, etc. In the basic algorithm tracking read transfers and calculating memory pressure should be enough to skip polling mode in devfreq. Signed-off-by: Lukasz Luba Signed-off-by: Krzysztof Kozlowski --- drivers/memory/samsung/exynos5422-dmc.c | 347 ++++++++++++++++++++++-- 1 file changed, 321 insertions(+), 26 deletions(-) diff --git a/drivers/memory/samsung/exynos5422-dmc.c b/drivers/memory/samsung/exynos5422-dmc.c index 0fe5f2186139..47dbf6d1789f 100644 --- a/drivers/memory/samsung/exynos5422-dmc.c +++ b/drivers/memory/samsung/exynos5422-dmc.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include #include @@ -35,6 +36,61 @@ #define USE_BPLL_TIMINGS (0) #define EXYNOS5_AREF_NORMAL (0x2e) +#define DREX_PPCCLKCON (0x0130) +#define DREX_PEREV2CONFIG (0x013c) +#define DREX_PMNC_PPC (0xE000) +#define DREX_CNTENS_PPC (0xE010) +#define DREX_CNTENC_PPC (0xE020) +#define DREX_INTENS_PPC (0xE030) +#define DREX_INTENC_PPC (0xE040) +#define DREX_FLAG_PPC (0xE050) +#define DREX_PMCNT2_PPC (0xE130) + +/* + * A value for register DREX_PMNC_PPC which should be written to reset + * the cycle counter CCNT (a reference wall clock). It sets zero to the + * CCNT counter. + */ +#define CC_RESET BIT(2) + +/* + * A value for register DREX_PMNC_PPC which does the reset of all performance + * counters to zero. + */ +#define PPC_COUNTER_RESET BIT(1) + +/* + * Enables all configured counters (including cycle counter). The value should + * be written to the register DREX_PMNC_PPC. + */ +#define PPC_ENABLE BIT(0) + +/* A value for register DREX_PPCCLKCON which enables performance events clock. + * Must be written before first access to the performance counters register + * set, otherwise it could crash. + */ +#define PEREV_CLK_EN BIT(0) + +/* + * Values which are used to enable counters, interrupts or configure flags of + * the performance counters. They configure counter 2 and cycle counter. + */ +#define PERF_CNT2 BIT(2) +#define PERF_CCNT BIT(31) + +/* + * Performance event types which are used for setting the preferred event + * to track in the counters. + * There is a set of different types, the values are from range 0 to 0x6f. + * These settings should be written to the configuration register which manages + * the type of the event (register DREX_PEREV2CONFIG). + */ +#define READ_TRANSFER_CH0 (0x6d) +#define READ_TRANSFER_CH1 (0x6f) + +#define PERF_COUNTER_START_VALUE 0xff000000 +#define PERF_EVENT_UP_DOWN_THRESHOLD 900000000ULL + /** * struct dmc_opp_table - Operating level desciption * @@ -85,6 +141,10 @@ struct exynos5_dmc { struct clk *mout_mx_mspll_ccore_phy; struct devfreq_event_dev **counter; int num_counters; + u64 last_overflow_ts[2]; + unsigned long load; + unsigned long total; + bool in_irq_mode; }; #define TIMING_FIELD(t_name, t_bit_beg, t_bit_end) \ @@ -653,6 +713,173 @@ static int exynos5_counters_get(struct exynos5_dmc *dmc, return 0; } +/** + * exynos5_dmc_start_perf_events() - Setup and start performance event counters + * @dmc: device for which the counters are going to be checked + * @beg_value: initial value for the counter + * + * Function which enables needed counters, interrupts and sets initial values + * then starts the counters. + */ +static void exynos5_dmc_start_perf_events(struct exynos5_dmc *dmc, + u32 beg_value) +{ + /* Enable interrupts for counter 2 */ + writel(PERF_CNT2, dmc->base_drexi0 + DREX_INTENS_PPC); + writel(PERF_CNT2, dmc->base_drexi1 + DREX_INTENS_PPC); + + /* Enable counter 2 and CCNT */ + writel(PERF_CNT2 | PERF_CCNT, dmc->base_drexi0 + DREX_CNTENS_PPC); + writel(PERF_CNT2 | PERF_CCNT, dmc->base_drexi1 + DREX_CNTENS_PPC); + + /* Clear overflow flag for all counters */ + writel(PERF_CNT2 | PERF_CCNT, dmc->base_drexi0 + DREX_FLAG_PPC); + writel(PERF_CNT2 | PERF_CCNT, dmc->base_drexi1 + DREX_FLAG_PPC); + + /* Reset all counters */ + writel(CC_RESET | PPC_COUNTER_RESET, dmc->base_drexi0 + DREX_PMNC_PPC); + writel(CC_RESET | PPC_COUNTER_RESET, dmc->base_drexi1 + DREX_PMNC_PPC); + + /* + * Set start value for the counters, the number of samples that + * will be gathered is calculated as: 0xffffffff - beg_value + */ + writel(beg_value, dmc->base_drexi0 + DREX_PMCNT2_PPC); + writel(beg_value, dmc->base_drexi1 + DREX_PMCNT2_PPC); + + /* Start all counters */ + writel(PPC_ENABLE, dmc->base_drexi0 + DREX_PMNC_PPC); + writel(PPC_ENABLE, dmc->base_drexi1 + DREX_PMNC_PPC); +} + +/** + * exynos5_dmc_perf_events_calc() - Calculate utilization + * @dmc: device for which the counters are going to be checked + * @diff_ts: time between last interrupt and current one + * + * Function which calculates needed utilization for the devfreq governor. + * It prepares values for 'busy_time' and 'total_time' based on elapsed time + * between interrupts, which approximates utilization. + */ +static void exynos5_dmc_perf_events_calc(struct exynos5_dmc *dmc, u64 diff_ts) +{ + /* + * This is a simple algorithm for managing traffic on DMC. + * When there is almost no load the counters overflow every 4s, + * no mater the DMC frequency. + * The high load might be approximated using linear function. + * Knowing that, simple calculation can provide 'busy_time' and + * 'total_time' to the devfreq governor which picks up target + * frequency. + * We want a fast ramp up and slow decay in frequency change function. + */ + if (diff_ts < PERF_EVENT_UP_DOWN_THRESHOLD) { + /* + * Set higher utilization for the simple_ondemand governor. + * The governor should increase the frequency of the DMC. + */ + dmc->load = 70; + dmc->total = 100; + } else { + /* + * Set low utilization for the simple_ondemand governor. + * The governor should decrease the frequency of the DMC. + */ + dmc->load = 35; + dmc->total = 100; + } + + dev_dbg(dmc->dev, "diff_ts=%llu\n", diff_ts); +} + +/** + * exynos5_dmc_perf_events_check() - Checks the status of the counters + * @dmc: device for which the counters are going to be checked + * + * Function which is called from threaded IRQ to check the counters state + * and to call approximation for the needed utilization. + */ +static void exynos5_dmc_perf_events_check(struct exynos5_dmc *dmc) +{ + u32 val; + u64 diff_ts, ts; + + ts = ktime_get_ns(); + + /* Stop all counters */ + writel(0, dmc->base_drexi0 + DREX_PMNC_PPC); + writel(0, dmc->base_drexi1 + DREX_PMNC_PPC); + + /* Check the source in interrupt flag registers (which channel) */ + val = readl(dmc->base_drexi0 + DREX_FLAG_PPC); + if (val) { + diff_ts = ts - dmc->last_overflow_ts[0]; + dmc->last_overflow_ts[0] = ts; + dev_dbg(dmc->dev, "drex0 0xE050 val= 0x%08x\n", val); + } else { + val = readl(dmc->base_drexi1 + DREX_FLAG_PPC); + diff_ts = ts - dmc->last_overflow_ts[1]; + dmc->last_overflow_ts[1] = ts; + dev_dbg(dmc->dev, "drex1 0xE050 val= 0x%08x\n", val); + } + + exynos5_dmc_perf_events_calc(dmc, diff_ts); + + exynos5_dmc_start_perf_events(dmc, PERF_COUNTER_START_VALUE); +} + +/** + * exynos5_dmc_enable_perf_events() - Enable performance events + * @dmc: device for which the counters are going to be checked + * + * Function which is setup needed environment and enables counters. + */ +static void exynos5_dmc_enable_perf_events(struct exynos5_dmc *dmc) +{ + u64 ts; + + /* Enable Performance Event Clock */ + writel(PEREV_CLK_EN, dmc->base_drexi0 + DREX_PPCCLKCON); + writel(PEREV_CLK_EN, dmc->base_drexi1 + DREX_PPCCLKCON); + + /* Select read transfers as performance event2 */ + writel(READ_TRANSFER_CH0, dmc->base_drexi0 + DREX_PEREV2CONFIG); + writel(READ_TRANSFER_CH1, dmc->base_drexi1 + DREX_PEREV2CONFIG); + + ts = ktime_get_ns(); + dmc->last_overflow_ts[0] = ts; + dmc->last_overflow_ts[1] = ts; + + /* Devfreq shouldn't be faster than initialization, play safe though. */ + dmc->load = 99; + dmc->total = 100; +} + +/** + * exynos5_dmc_disable_perf_events() - Disable performance events + * @dmc: device for which the counters are going to be checked + * + * Function which stops, disables performance event counters and interrupts. + */ +static void exynos5_dmc_disable_perf_events(struct exynos5_dmc *dmc) +{ + /* Stop all counters */ + writel(0, dmc->base_drexi0 + DREX_PMNC_PPC); + writel(0, dmc->base_drexi1 + DREX_PMNC_PPC); + + /* Disable interrupts for counter 2 */ + writel(PERF_CNT2, dmc->base_drexi0 + DREX_INTENC_PPC); + writel(PERF_CNT2, dmc->base_drexi1 + DREX_INTENC_PPC); + + /* Disable counter 2 and CCNT */ + writel(PERF_CNT2 | PERF_CCNT, dmc->base_drexi0 + DREX_CNTENC_PPC); + writel(PERF_CNT2 | PERF_CCNT, dmc->base_drexi1 + DREX_CNTENC_PPC); + + /* Clear overflow flag for all counters */ + writel(PERF_CNT2 | PERF_CCNT, dmc->base_drexi0 + DREX_FLAG_PPC); + writel(PERF_CNT2 | PERF_CCNT, dmc->base_drexi1 + DREX_FLAG_PPC); +} + /** * exynos5_dmc_get_status() - Read current DMC performance statistics. * @dev: device for which the statistics are requested @@ -669,18 +896,24 @@ static int exynos5_dmc_get_status(struct device *dev, unsigned long load, total; int ret; - ret = exynos5_counters_get(dmc, &load, &total); - if (ret < 0) - return -EINVAL; + if (dmc->in_irq_mode) { + stat->current_frequency = dmc->curr_rate; + stat->busy_time = dmc->load; + stat->total_time = dmc->total; + } else { + ret = exynos5_counters_get(dmc, &load, &total); + if (ret < 0) + return -EINVAL; - /* To protect from overflow in calculation ratios, divide by 1024 */ - stat->busy_time = load >> 10; - stat->total_time = total >> 10; + /* To protect from overflow, divide by 1024 */ + stat->busy_time = load >> 10; + stat->total_time = total >> 10; - ret = exynos5_counters_set_event(dmc); - if (ret < 0) { - dev_err(dev, "could not set event counter\n"); - return ret; + ret = exynos5_counters_set_event(dmc); + if (ret < 0) { + dev_err(dev, "could not set event counter\n"); + return ret; + } } return 0; @@ -712,7 +945,6 @@ static int exynos5_dmc_get_cur_freq(struct device *dev, unsigned long *freq) * It provides to the devfreq framework needed functions and polling period. */ static struct devfreq_dev_profile exynos5_dmc_df_profile = { - .polling_ms = 500, .target = exynos5_dmc_target, .get_dev_status = exynos5_dmc_get_status, .get_cur_freq = exynos5_dmc_get_cur_freq, @@ -1108,6 +1340,24 @@ static inline int exynos5_dmc_set_pause_on_switching(struct exynos5_dmc *dmc) return 0; } +static irqreturn_t dmc_irq_thread(int irq, void *priv) +{ + int res; + struct exynos5_dmc *dmc = priv; + + mutex_lock(&dmc->df->lock); + + exynos5_dmc_perf_events_check(dmc); + + res = update_devfreq(dmc->df); + if (res) + dev_warn(dmc->dev, "devfreq failed with %d\n", res); + + mutex_unlock(&dmc->df->lock); + + return IRQ_HANDLED; +} + /** * exynos5_dmc_probe() - Probe function for the DMC driver * @pdev: platform device for which the driver is going to be initialized @@ -1125,6 +1375,7 @@ static int exynos5_dmc_probe(struct platform_device *pdev) struct device_node *np = dev->of_node; struct exynos5_dmc *dmc; struct resource *res; + int irq[2]; dmc = devm_kzalloc(dev, sizeof(*dmc), GFP_KERNEL); if (!dmc) @@ -1172,24 +1423,59 @@ static int exynos5_dmc_probe(struct platform_device *pdev) goto remove_clocks; } - ret = exynos5_performance_counters_init(dmc); - if (ret) { - dev_warn(dev, "couldn't probe performance counters\n"); - goto remove_clocks; - } - ret = exynos5_dmc_set_pause_on_switching(dmc); if (ret) { dev_warn(dev, "couldn't get access to PAUSE register\n"); - goto err_devfreq_add; + goto remove_clocks; + } + + /* There is two modes in which the driver works: polling or IRQ */ + irq[0] = platform_get_irq_byname(pdev, "drex_0"); + irq[1] = platform_get_irq_byname(pdev, "drex_1"); + if (irq[0] > 0 && irq[1] > 0) { + ret = devm_request_threaded_irq(dev, irq[0], NULL, + dmc_irq_thread, IRQF_ONESHOT, + dev_name(dev), dmc); + if (ret) { + dev_err(dev, "couldn't grab IRQ\n"); + goto remove_clocks; + } + + ret = devm_request_threaded_irq(dev, irq[1], NULL, + dmc_irq_thread, IRQF_ONESHOT, + dev_name(dev), dmc); + if (ret) { + dev_err(dev, "couldn't grab IRQ\n"); + goto remove_clocks; + } + + /* + * Setup default thresholds for the devfreq governor. + * The values are chosen based on experiments. + */ + dmc->gov_data.upthreshold = 55; + dmc->gov_data.downdifferential = 5; + + exynos5_dmc_enable_perf_events(dmc); + + dmc->in_irq_mode = 1; + } else { + ret = exynos5_performance_counters_init(dmc); + if (ret) { + dev_warn(dev, "couldn't probe performance counters\n"); + goto remove_clocks; + } + + /* + * Setup default thresholds for the devfreq governor. + * The values are chosen based on experiments. + */ + dmc->gov_data.upthreshold = 30; + dmc->gov_data.downdifferential = 5; + + exynos5_dmc_df_profile.polling_ms = 500; } - /* - * Setup default thresholds for the devfreq governor. - * The values are chosen based on experiments. - */ - dmc->gov_data.upthreshold = 30; - dmc->gov_data.downdifferential = 5; dmc->df = devm_devfreq_add_device(dev, &exynos5_dmc_df_profile, DEVFREQ_GOV_SIMPLE_ONDEMAND, @@ -1200,12 +1486,18 @@ static int exynos5_dmc_probe(struct platform_device *pdev) goto err_devfreq_add; } + if (dmc->in_irq_mode) + exynos5_dmc_start_perf_events(dmc, PERF_COUNTER_START_VALUE); + dev_info(dev, "DMC initialized\n"); return 0; err_devfreq_add: - exynos5_counters_disable_edev(dmc); + if (dmc->in_irq_mode) + exynos5_dmc_disable_perf_events(dmc); + else + exynos5_counters_disable_edev(dmc); remove_clocks: clk_disable_unprepare(dmc->mout_bpll); clk_disable_unprepare(dmc->fout_bpll); @@ -1225,7 +1517,10 @@ static int exynos5_dmc_remove(struct platform_device *pdev) { struct exynos5_dmc *dmc = dev_get_drvdata(&pdev->dev); - exynos5_counters_disable_edev(dmc); + if (dmc->in_irq_mode) + exynos5_dmc_disable_perf_events(dmc); + else + exynos5_counters_disable_edev(dmc); clk_disable_unprepare(dmc->mout_bpll); clk_disable_unprepare(dmc->fout_bpll);