From 54104ee023333e3bd8062ff1cbc312ea4c5bf733 Mon Sep 17 00:00:00 2001 From: Kavyasree Kotagiri Date: Wed, 3 Nov 2021 11:49:35 +0530 Subject: [PATCH] clk: lan966x: Add lan966x SoC clock driver This adds Generic Clock Controller driver for lan966x SoC. Lan966x clock controller contains 3 PLLs - cpu_clk, ddr_clk and sys_clk. It generates and supplies clock to various peripherals within SoC. Register settings required to provide GCK clocking to a peripheral is as below: GCK_SRC_SEL = Select clock source. GCK_PRESCALER = Set divider value. GCK_ENA = 1 - Enable GCK clock. Signed-off-by: Kavyasree Kotagiri Co-developed-by: Horatiu Vultur Signed-off-by: Horatiu Vultur Acked-by: Nicolas Ferre Signed-off-by: Nicolas Ferre Link: https://lore.kernel.org/r/20211103061935.25677-4-kavyasree.kotagiri@microchip.com --- drivers/clk/Kconfig | 7 ++ drivers/clk/Makefile | 1 + drivers/clk/clk-lan966x.c | 240 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 248 insertions(+) create mode 100644 drivers/clk/clk-lan966x.c diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig index c5b3dc97396a..1b992a554ff8 100644 --- a/drivers/clk/Kconfig +++ b/drivers/clk/Kconfig @@ -221,6 +221,13 @@ config COMMON_CLK_GEMINI This driver supports the SoC clocks on the Cortina Systems Gemini platform, also known as SL3516 or CS3516. +config COMMON_CLK_LAN966X + bool "Generic Clock Controller driver for LAN966X SoC" + help + This driver provides support for Generic Clock Controller(GCK) on + LAN966X SoC. GCK generates and supplies clock to various peripherals + within the SoC. + config COMMON_CLK_ASPEED bool "Clock driver for Aspeed BMC SoCs" depends on ARCH_ASPEED || COMPILE_TEST diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index e42312121e51..d8565ef01b34 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -37,6 +37,7 @@ obj-$(CONFIG_ARCH_HIGHBANK) += clk-highbank.o obj-$(CONFIG_CLK_HSDK) += clk-hsdk-pll.o obj-$(CONFIG_COMMON_CLK_K210) += clk-k210.o obj-$(CONFIG_LMK04832) += clk-lmk04832.o +obj-$(CONFIG_COMMON_CLK_LAN966X) += clk-lan966x.o obj-$(CONFIG_COMMON_CLK_LOCHNAGAR) += clk-lochnagar.o obj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o obj-$(CONFIG_COMMON_CLK_MAX9485) += clk-max9485.o diff --git a/drivers/clk/clk-lan966x.c b/drivers/clk/clk-lan966x.c new file mode 100644 index 000000000000..d99cc639eb04 --- /dev/null +++ b/drivers/clk/clk-lan966x.c @@ -0,0 +1,240 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Microchip LAN966x SoC Clock driver. + * + * Copyright (C) 2021 Microchip Technology, Inc. and its subsidiaries + * + * Author: Kavyasree Kotagiri + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#define GCK_ENA BIT(0) +#define GCK_SRC_SEL GENMASK(9, 8) +#define GCK_PRESCALER GENMASK(23, 16) + +#define DIV_MAX 255 + +static const char *clk_names[N_CLOCKS] = { + "qspi0", "qspi1", "qspi2", "sdmmc0", + "pi", "mcan0", "mcan1", "flexcom0", + "flexcom1", "flexcom2", "flexcom3", + "flexcom4", "timer1", "usb_refclk", +}; + +struct lan966x_gck { + struct clk_hw hw; + void __iomem *reg; +}; +#define to_lan966x_gck(hw) container_of(hw, struct lan966x_gck, hw) + +static const struct clk_parent_data lan966x_gck_pdata[] = { + { .fw_name = "cpu", }, + { .fw_name = "ddr", }, + { .fw_name = "sys", }, +}; + +static struct clk_init_data init = { + .parent_data = lan966x_gck_pdata, + .num_parents = ARRAY_SIZE(lan966x_gck_pdata), +}; + +static void __iomem *base; + +static int lan966x_gck_enable(struct clk_hw *hw) +{ + struct lan966x_gck *gck = to_lan966x_gck(hw); + u32 val = readl(gck->reg); + + val |= GCK_ENA; + writel(val, gck->reg); + + return 0; +} + +static void lan966x_gck_disable(struct clk_hw *hw) +{ + struct lan966x_gck *gck = to_lan966x_gck(hw); + u32 val = readl(gck->reg); + + val &= ~GCK_ENA; + writel(val, gck->reg); +} + +static int lan966x_gck_set_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long parent_rate) +{ + struct lan966x_gck *gck = to_lan966x_gck(hw); + u32 div, val = readl(gck->reg); + + if (rate == 0 || parent_rate == 0) + return -EINVAL; + + /* Set Prescalar */ + div = parent_rate / rate; + val &= ~GCK_PRESCALER; + val |= FIELD_PREP(GCK_PRESCALER, (div - 1)); + writel(val, gck->reg); + + return 0; +} + +static long lan966x_gck_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + unsigned int div; + + if (rate == 0 || *parent_rate == 0) + return -EINVAL; + + if (rate >= *parent_rate) + return *parent_rate; + + div = DIV_ROUND_CLOSEST(*parent_rate, rate); + + return *parent_rate / div; +} + +static unsigned long lan966x_gck_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct lan966x_gck *gck = to_lan966x_gck(hw); + u32 div, val = readl(gck->reg); + + div = FIELD_GET(GCK_PRESCALER, val); + + return parent_rate / (div + 1); +} + +static int lan966x_gck_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + struct clk_hw *parent; + int i; + + for (i = 0; i < clk_hw_get_num_parents(hw); ++i) { + parent = clk_hw_get_parent_by_index(hw, i); + if (!parent) + continue; + + /* Allowed prescaler divider range is 0-255 */ + if (clk_hw_get_rate(parent) / req->rate <= DIV_MAX) { + req->best_parent_hw = parent; + req->best_parent_rate = clk_hw_get_rate(parent); + + return 0; + } + } + + return -EINVAL; +} + +static u8 lan966x_gck_get_parent(struct clk_hw *hw) +{ + struct lan966x_gck *gck = to_lan966x_gck(hw); + u32 val = readl(gck->reg); + + return FIELD_GET(GCK_SRC_SEL, val); +} + +static int lan966x_gck_set_parent(struct clk_hw *hw, u8 index) +{ + struct lan966x_gck *gck = to_lan966x_gck(hw); + u32 val = readl(gck->reg); + + val &= ~GCK_SRC_SEL; + val |= FIELD_PREP(GCK_SRC_SEL, index); + writel(val, gck->reg); + + return 0; +} + +static const struct clk_ops lan966x_gck_ops = { + .enable = lan966x_gck_enable, + .disable = lan966x_gck_disable, + .set_rate = lan966x_gck_set_rate, + .round_rate = lan966x_gck_round_rate, + .recalc_rate = lan966x_gck_recalc_rate, + .determine_rate = lan966x_gck_determine_rate, + .set_parent = lan966x_gck_set_parent, + .get_parent = lan966x_gck_get_parent, +}; + +static struct clk_hw *lan966x_gck_clk_register(struct device *dev, int i) +{ + struct lan966x_gck *priv; + int ret; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return ERR_PTR(-ENOMEM); + + priv->reg = base + (i * 4); + priv->hw.init = &init; + ret = devm_clk_hw_register(dev, &priv->hw); + if (ret) + return ERR_PTR(ret); + + return &priv->hw; +}; + +static int lan966x_clk_probe(struct platform_device *pdev) +{ + struct clk_hw_onecell_data *hw_data; + struct device *dev = &pdev->dev; + int i; + + hw_data = devm_kzalloc(dev, struct_size(hw_data, hws, N_CLOCKS), + GFP_KERNEL); + if (!hw_data) + return -ENOMEM; + + base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(base)) + return PTR_ERR(base); + + init.ops = &lan966x_gck_ops; + + hw_data->num = N_CLOCKS; + + for (i = 0; i < N_CLOCKS; i++) { + init.name = clk_names[i]; + hw_data->hws[i] = lan966x_gck_clk_register(dev, i); + if (IS_ERR(hw_data->hws[i])) { + dev_err(dev, "failed to register %s clock\n", + init.name); + return PTR_ERR(hw_data->hws[i]); + } + } + + return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, hw_data); +} + +static const struct of_device_id lan966x_clk_dt_ids[] = { + { .compatible = "microchip,lan966x-gck", }, + { } +}; +MODULE_DEVICE_TABLE(of, lan966x_clk_dt_ids); + +static struct platform_driver lan966x_clk_driver = { + .probe = lan966x_clk_probe, + .driver = { + .name = "lan966x-clk", + .of_match_table = lan966x_clk_dt_ids, + }, +}; +builtin_platform_driver(lan966x_clk_driver); + +MODULE_AUTHOR("Kavyasree Kotagiri "); +MODULE_DESCRIPTION("LAN966X clock driver"); +MODULE_LICENSE("GPL v2");