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![Damien Le Moal](/assets/img/avatar_default.png)
The Canaan Kendryte K210 RISC-V SoC includes a DW apb_ssi v4 controller which is documented to have a 32 words deep TX and RX FIFO. The FIFO length detection in spi_hw_init() correctly detects this value. However, when the controller RX FIFO is filled up to 32 entries (RXFLR = 32), an RX FIFO overrun error occurs. This likely due to a hardware bug which can be avoided by force setting the fifo_len field of struct dw_spi to 31. Define the dw_spi_canaan_k210_init() function to force set fifo_len to 31 when the device node compatible string is "canaan,k210-spi". Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Acked-by: Serge Semin <fancer.lancer@gmail.com> Link: https://lore.kernel.org/r/20201206011817.11700-4-damien.lemoal@wdc.com Signed-off-by: Mark Brown <broonie@kernel.org>
379 lines
10 KiB
C
379 lines
10 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Memory-mapped interface driver for DW SPI Core
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*
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* Copyright (c) 2010, Octasic semiconductor.
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*/
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#include <linux/clk.h>
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#include <linux/err.h>
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#include <linux/platform_device.h>
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#include <linux/pm_runtime.h>
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#include <linux/slab.h>
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#include <linux/spi/spi.h>
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#include <linux/scatterlist.h>
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#include <linux/mfd/syscon.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/of_platform.h>
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#include <linux/acpi.h>
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#include <linux/property.h>
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#include <linux/regmap.h>
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#include <linux/reset.h>
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#include "spi-dw.h"
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#define DRIVER_NAME "dw_spi_mmio"
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struct dw_spi_mmio {
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struct dw_spi dws;
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struct clk *clk;
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struct clk *pclk;
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void *priv;
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struct reset_control *rstc;
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};
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#define MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL 0x24
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#define OCELOT_IF_SI_OWNER_OFFSET 4
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#define JAGUAR2_IF_SI_OWNER_OFFSET 6
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#define MSCC_IF_SI_OWNER_MASK GENMASK(1, 0)
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#define MSCC_IF_SI_OWNER_SISL 0
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#define MSCC_IF_SI_OWNER_SIBM 1
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#define MSCC_IF_SI_OWNER_SIMC 2
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#define MSCC_SPI_MST_SW_MODE 0x14
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#define MSCC_SPI_MST_SW_MODE_SW_PIN_CTRL_MODE BIT(13)
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#define MSCC_SPI_MST_SW_MODE_SW_SPI_CS(x) (x << 5)
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#define SPARX5_FORCE_ENA 0xa4
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#define SPARX5_FORCE_VAL 0xa8
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struct dw_spi_mscc {
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struct regmap *syscon;
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void __iomem *spi_mst; /* Not sparx5 */
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};
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/*
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* The Designware SPI controller (referred to as master in the documentation)
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* automatically deasserts chip select when the tx fifo is empty. The chip
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* selects then needs to be either driven as GPIOs or, for the first 4 using the
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* the SPI boot controller registers. the final chip select is an OR gate
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* between the Designware SPI controller and the SPI boot controller.
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*/
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static void dw_spi_mscc_set_cs(struct spi_device *spi, bool enable)
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{
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struct dw_spi *dws = spi_master_get_devdata(spi->master);
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struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws);
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struct dw_spi_mscc *dwsmscc = dwsmmio->priv;
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u32 cs = spi->chip_select;
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if (cs < 4) {
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u32 sw_mode = MSCC_SPI_MST_SW_MODE_SW_PIN_CTRL_MODE;
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if (!enable)
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sw_mode |= MSCC_SPI_MST_SW_MODE_SW_SPI_CS(BIT(cs));
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writel(sw_mode, dwsmscc->spi_mst + MSCC_SPI_MST_SW_MODE);
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}
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dw_spi_set_cs(spi, enable);
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}
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static int dw_spi_mscc_init(struct platform_device *pdev,
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struct dw_spi_mmio *dwsmmio,
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const char *cpu_syscon, u32 if_si_owner_offset)
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{
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struct dw_spi_mscc *dwsmscc;
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dwsmscc = devm_kzalloc(&pdev->dev, sizeof(*dwsmscc), GFP_KERNEL);
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if (!dwsmscc)
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return -ENOMEM;
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dwsmscc->spi_mst = devm_platform_ioremap_resource(pdev, 1);
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if (IS_ERR(dwsmscc->spi_mst)) {
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dev_err(&pdev->dev, "SPI_MST region map failed\n");
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return PTR_ERR(dwsmscc->spi_mst);
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}
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dwsmscc->syscon = syscon_regmap_lookup_by_compatible(cpu_syscon);
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if (IS_ERR(dwsmscc->syscon))
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return PTR_ERR(dwsmscc->syscon);
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/* Deassert all CS */
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writel(0, dwsmscc->spi_mst + MSCC_SPI_MST_SW_MODE);
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/* Select the owner of the SI interface */
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regmap_update_bits(dwsmscc->syscon, MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL,
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MSCC_IF_SI_OWNER_MASK << if_si_owner_offset,
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MSCC_IF_SI_OWNER_SIMC << if_si_owner_offset);
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dwsmmio->dws.set_cs = dw_spi_mscc_set_cs;
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dwsmmio->priv = dwsmscc;
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return 0;
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}
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static int dw_spi_mscc_ocelot_init(struct platform_device *pdev,
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struct dw_spi_mmio *dwsmmio)
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{
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return dw_spi_mscc_init(pdev, dwsmmio, "mscc,ocelot-cpu-syscon",
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OCELOT_IF_SI_OWNER_OFFSET);
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}
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static int dw_spi_mscc_jaguar2_init(struct platform_device *pdev,
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struct dw_spi_mmio *dwsmmio)
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{
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return dw_spi_mscc_init(pdev, dwsmmio, "mscc,jaguar2-cpu-syscon",
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JAGUAR2_IF_SI_OWNER_OFFSET);
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}
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/*
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* The Designware SPI controller (referred to as master in the
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* documentation) automatically deasserts chip select when the tx fifo
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* is empty. The chip selects then needs to be driven by a CS override
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* register. enable is an active low signal.
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*/
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static void dw_spi_sparx5_set_cs(struct spi_device *spi, bool enable)
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{
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struct dw_spi *dws = spi_master_get_devdata(spi->master);
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struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws);
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struct dw_spi_mscc *dwsmscc = dwsmmio->priv;
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u8 cs = spi->chip_select;
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if (!enable) {
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/* CS override drive enable */
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regmap_write(dwsmscc->syscon, SPARX5_FORCE_ENA, 1);
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/* Now set CSx enabled */
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regmap_write(dwsmscc->syscon, SPARX5_FORCE_VAL, ~BIT(cs));
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/* Allow settle */
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usleep_range(1, 5);
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} else {
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/* CS value */
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regmap_write(dwsmscc->syscon, SPARX5_FORCE_VAL, ~0);
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/* Allow settle */
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usleep_range(1, 5);
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/* CS override drive disable */
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regmap_write(dwsmscc->syscon, SPARX5_FORCE_ENA, 0);
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}
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dw_spi_set_cs(spi, enable);
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}
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static int dw_spi_mscc_sparx5_init(struct platform_device *pdev,
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struct dw_spi_mmio *dwsmmio)
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{
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const char *syscon_name = "microchip,sparx5-cpu-syscon";
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struct device *dev = &pdev->dev;
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struct dw_spi_mscc *dwsmscc;
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if (!IS_ENABLED(CONFIG_SPI_MUX)) {
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dev_err(dev, "This driver needs CONFIG_SPI_MUX\n");
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return -EOPNOTSUPP;
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}
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dwsmscc = devm_kzalloc(dev, sizeof(*dwsmscc), GFP_KERNEL);
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if (!dwsmscc)
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return -ENOMEM;
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dwsmscc->syscon =
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syscon_regmap_lookup_by_compatible(syscon_name);
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if (IS_ERR(dwsmscc->syscon)) {
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dev_err(dev, "No syscon map %s\n", syscon_name);
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return PTR_ERR(dwsmscc->syscon);
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}
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dwsmmio->dws.set_cs = dw_spi_sparx5_set_cs;
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dwsmmio->priv = dwsmscc;
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return 0;
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}
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static int dw_spi_alpine_init(struct platform_device *pdev,
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struct dw_spi_mmio *dwsmmio)
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{
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dwsmmio->dws.caps = DW_SPI_CAP_CS_OVERRIDE;
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return 0;
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}
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static int dw_spi_dw_apb_init(struct platform_device *pdev,
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struct dw_spi_mmio *dwsmmio)
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{
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dw_spi_dma_setup_generic(&dwsmmio->dws);
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return 0;
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}
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static int dw_spi_dwc_ssi_init(struct platform_device *pdev,
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struct dw_spi_mmio *dwsmmio)
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{
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dwsmmio->dws.caps = DW_SPI_CAP_DWC_SSI;
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dw_spi_dma_setup_generic(&dwsmmio->dws);
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return 0;
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}
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static int dw_spi_keembay_init(struct platform_device *pdev,
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struct dw_spi_mmio *dwsmmio)
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{
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dwsmmio->dws.caps = DW_SPI_CAP_KEEMBAY_MST | DW_SPI_CAP_DWC_SSI;
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return 0;
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}
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static int dw_spi_canaan_k210_init(struct platform_device *pdev,
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struct dw_spi_mmio *dwsmmio)
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{
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/*
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* The Canaan Kendryte K210 SoC DW apb_ssi v4 spi controller is
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* documented to have a 32 word deep TX and RX FIFO, which
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* spi_hw_init() detects. However, when the RX FIFO is filled up to
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* 32 entries (RXFLR = 32), an RX FIFO overrun error occurs. Avoid this
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* problem by force setting fifo_len to 31.
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*/
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dwsmmio->dws.fifo_len = 31;
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return 0;
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}
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static int dw_spi_mmio_probe(struct platform_device *pdev)
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{
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int (*init_func)(struct platform_device *pdev,
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struct dw_spi_mmio *dwsmmio);
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struct dw_spi_mmio *dwsmmio;
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struct resource *mem;
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struct dw_spi *dws;
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int ret;
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int num_cs;
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dwsmmio = devm_kzalloc(&pdev->dev, sizeof(struct dw_spi_mmio),
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GFP_KERNEL);
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if (!dwsmmio)
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return -ENOMEM;
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dws = &dwsmmio->dws;
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/* Get basic io resource and map it */
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dws->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &mem);
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if (IS_ERR(dws->regs))
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return PTR_ERR(dws->regs);
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dws->paddr = mem->start;
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dws->irq = platform_get_irq(pdev, 0);
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if (dws->irq < 0)
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return dws->irq; /* -ENXIO */
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dwsmmio->clk = devm_clk_get(&pdev->dev, NULL);
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if (IS_ERR(dwsmmio->clk))
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return PTR_ERR(dwsmmio->clk);
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ret = clk_prepare_enable(dwsmmio->clk);
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if (ret)
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return ret;
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/* Optional clock needed to access the registers */
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dwsmmio->pclk = devm_clk_get_optional(&pdev->dev, "pclk");
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if (IS_ERR(dwsmmio->pclk)) {
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ret = PTR_ERR(dwsmmio->pclk);
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goto out_clk;
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}
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ret = clk_prepare_enable(dwsmmio->pclk);
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if (ret)
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goto out_clk;
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/* find an optional reset controller */
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dwsmmio->rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, "spi");
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if (IS_ERR(dwsmmio->rstc)) {
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ret = PTR_ERR(dwsmmio->rstc);
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goto out_clk;
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}
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reset_control_deassert(dwsmmio->rstc);
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dws->bus_num = pdev->id;
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dws->max_freq = clk_get_rate(dwsmmio->clk);
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device_property_read_u32(&pdev->dev, "reg-io-width", &dws->reg_io_width);
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num_cs = 4;
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device_property_read_u32(&pdev->dev, "num-cs", &num_cs);
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dws->num_cs = num_cs;
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init_func = device_get_match_data(&pdev->dev);
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if (init_func) {
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ret = init_func(pdev, dwsmmio);
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if (ret)
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goto out;
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}
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pm_runtime_enable(&pdev->dev);
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ret = dw_spi_add_host(&pdev->dev, dws);
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if (ret)
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goto out;
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platform_set_drvdata(pdev, dwsmmio);
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return 0;
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out:
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pm_runtime_disable(&pdev->dev);
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clk_disable_unprepare(dwsmmio->pclk);
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out_clk:
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clk_disable_unprepare(dwsmmio->clk);
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reset_control_assert(dwsmmio->rstc);
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return ret;
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}
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static int dw_spi_mmio_remove(struct platform_device *pdev)
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{
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struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev);
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dw_spi_remove_host(&dwsmmio->dws);
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pm_runtime_disable(&pdev->dev);
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clk_disable_unprepare(dwsmmio->pclk);
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clk_disable_unprepare(dwsmmio->clk);
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reset_control_assert(dwsmmio->rstc);
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return 0;
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}
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static const struct of_device_id dw_spi_mmio_of_match[] = {
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{ .compatible = "snps,dw-apb-ssi", .data = dw_spi_dw_apb_init},
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{ .compatible = "mscc,ocelot-spi", .data = dw_spi_mscc_ocelot_init},
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{ .compatible = "mscc,jaguar2-spi", .data = dw_spi_mscc_jaguar2_init},
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{ .compatible = "amazon,alpine-dw-apb-ssi", .data = dw_spi_alpine_init},
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{ .compatible = "renesas,rzn1-spi", .data = dw_spi_dw_apb_init},
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{ .compatible = "snps,dwc-ssi-1.01a", .data = dw_spi_dwc_ssi_init},
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{ .compatible = "intel,keembay-ssi", .data = dw_spi_keembay_init},
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{ .compatible = "microchip,sparx5-spi", dw_spi_mscc_sparx5_init},
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{ .compatible = "canaan,k210-spi", dw_spi_canaan_k210_init},
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{ /* end of table */}
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};
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MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);
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#ifdef CONFIG_ACPI
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static const struct acpi_device_id dw_spi_mmio_acpi_match[] = {
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{"HISI0173", (kernel_ulong_t)dw_spi_dw_apb_init},
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{},
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};
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MODULE_DEVICE_TABLE(acpi, dw_spi_mmio_acpi_match);
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#endif
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static struct platform_driver dw_spi_mmio_driver = {
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.probe = dw_spi_mmio_probe,
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.remove = dw_spi_mmio_remove,
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.driver = {
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.name = DRIVER_NAME,
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.of_match_table = dw_spi_mmio_of_match,
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.acpi_match_table = ACPI_PTR(dw_spi_mmio_acpi_match),
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},
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};
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module_platform_driver(dw_spi_mmio_driver);
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MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>");
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MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core");
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MODULE_LICENSE("GPL v2");
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