![Phil Edworthy](/assets/img/avatar_default.png)
The Synopsys SSI Controller has an interface clock, but most SoCs hide this away. However, on some SoCs you need to explicitly enable the interface clock in order to access the registers. Therefore, add support for an optional interface clock. Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com> Signed-off-by: Gareth Williams <gareth.williams.jx@renesas.com> Signed-off-by: Mark Brown <broonie@kernel.org>
257 lines
6.8 KiB
C
257 lines
6.8 KiB
C
/*
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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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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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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/interrupt.h>
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#include <linux/platform_device.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 "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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};
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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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struct dw_spi_mscc {
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struct regmap *syscon;
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void __iomem *spi_mst;
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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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struct resource *res;
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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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res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
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dwsmscc->spi_mst = devm_ioremap_resource(&pdev->dev, res);
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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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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.cs_override = 1;
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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 dw_spi *dws;
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struct resource *mem;
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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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mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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dws->regs = devm_ioremap_resource(&pdev->dev, mem);
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if (IS_ERR(dws->regs)) {
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dev_err(&pdev->dev, "SPI region map failed\n");
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return PTR_ERR(dws->regs);
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}
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dws->irq = platform_get_irq(pdev, 0);
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if (dws->irq < 0) {
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dev_err(&pdev->dev, "no irq resource?\n");
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return dws->irq; /* -ENXIO */
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}
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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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return PTR_ERR(dwsmmio->pclk);
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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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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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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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clk_disable_unprepare(dwsmmio->pclk);
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out_clk:
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clk_disable_unprepare(dwsmmio->clk);
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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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clk_disable_unprepare(dwsmmio->pclk);
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clk_disable_unprepare(dwsmmio->clk);
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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", },
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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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{ /* end of table */}
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};
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MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);
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static const struct acpi_device_id dw_spi_mmio_acpi_match[] = {
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{"HISI0173", 0},
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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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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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