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/*
* Memory-mapped interface driver for DW SPI Core
*
* Copyright (c) 2010, Octasic semiconductor.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*/
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/scatterlist.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/of_platform.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include "spi-dw.h"
#define DRIVER_NAME "dw_spi_mmio"
struct dw_spi_mmio {
struct dw_spi dws;
struct clk *clk;
void *priv;
};
#define MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL 0x24
#define OCELOT_IF_SI_OWNER_MASK GENMASK(5, 4)
#define OCELOT_IF_SI_OWNER_OFFSET 4
#define MSCC_IF_SI_OWNER_SISL 0
#define MSCC_IF_SI_OWNER_SIBM 1
#define MSCC_IF_SI_OWNER_SIMC 2
#define MSCC_SPI_MST_SW_MODE 0x14
#define MSCC_SPI_MST_SW_MODE_SW_PIN_CTRL_MODE BIT(13)
#define MSCC_SPI_MST_SW_MODE_SW_SPI_CS(x) (x << 5)
struct dw_spi_mscc {
struct regmap *syscon;
void __iomem *spi_mst;
};
/*
* The Designware SPI controller (referred to as master in the documentation)
* automatically deasserts chip select when the tx fifo is empty. The chip
* selects then needs to be either driven as GPIOs or, for the first 4 using the
* the SPI boot controller registers. the final chip select is an OR gate
* between the Designware SPI controller and the SPI boot controller.
*/
static void dw_spi_mscc_set_cs(struct spi_device *spi, bool enable)
{
struct dw_spi *dws = spi_master_get_devdata(spi->master);
struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws);
struct dw_spi_mscc *dwsmscc = dwsmmio->priv;
u32 cs = spi->chip_select;
if (cs < 4) {
u32 sw_mode = MSCC_SPI_MST_SW_MODE_SW_PIN_CTRL_MODE;
if (!enable)
sw_mode |= MSCC_SPI_MST_SW_MODE_SW_SPI_CS(BIT(cs));
writel(sw_mode, dwsmscc->spi_mst + MSCC_SPI_MST_SW_MODE);
}
dw_spi_set_cs(spi, enable);
}
static int dw_spi_mscc_init(struct platform_device *pdev,
struct dw_spi_mmio *dwsmmio)
{
struct dw_spi_mscc *dwsmscc;
struct resource *res;
dwsmscc = devm_kzalloc(&pdev->dev, sizeof(*dwsmscc), GFP_KERNEL);
if (!dwsmscc)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
dwsmscc->spi_mst = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(dwsmscc->spi_mst)) {
dev_err(&pdev->dev, "SPI_MST region map failed\n");
return PTR_ERR(dwsmscc->spi_mst);
}
dwsmscc->syscon = syscon_regmap_lookup_by_compatible("mscc,ocelot-cpu-syscon");
if (IS_ERR(dwsmscc->syscon))
return PTR_ERR(dwsmscc->syscon);
/* Deassert all CS */
writel(0, dwsmscc->spi_mst + MSCC_SPI_MST_SW_MODE);
/* Select the owner of the SI interface */
regmap_update_bits(dwsmscc->syscon, MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL,
OCELOT_IF_SI_OWNER_MASK,
MSCC_IF_SI_OWNER_SIMC << OCELOT_IF_SI_OWNER_OFFSET);
dwsmmio->dws.set_cs = dw_spi_mscc_set_cs;
dwsmmio->priv = dwsmscc;
return 0;
}
static int dw_spi_mmio_probe(struct platform_device *pdev)
{
int (*init_func)(struct platform_device *pdev,
struct dw_spi_mmio *dwsmmio);
struct dw_spi_mmio *dwsmmio;
struct dw_spi *dws;
struct resource *mem;
int ret;
int num_cs;
dwsmmio = devm_kzalloc(&pdev->dev, sizeof(struct dw_spi_mmio),
GFP_KERNEL);
if (!dwsmmio)
return -ENOMEM;
dws = &dwsmmio->dws;
/* Get basic io resource and map it */
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
dws->regs = devm_ioremap_resource(&pdev->dev, mem);
if (IS_ERR(dws->regs)) {
dev_err(&pdev->dev, "SPI region map failed\n");
return PTR_ERR(dws->regs);
}
dws->irq = platform_get_irq(pdev, 0);
if (dws->irq < 0) {
dev_err(&pdev->dev, "no irq resource?\n");
return dws->irq; /* -ENXIO */
}
dwsmmio->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(dwsmmio->clk))
return PTR_ERR(dwsmmio->clk);
ret = clk_prepare_enable(dwsmmio->clk);
if (ret)
return ret;
dws->bus_num = pdev->id;
dws->max_freq = clk_get_rate(dwsmmio->clk);
device_property_read_u32(&pdev->dev, "reg-io-width", &dws->reg_io_width);
num_cs = 4;
device_property_read_u32(&pdev->dev, "num-cs", &num_cs);
dws->num_cs = num_cs;
if (pdev->dev.of_node) {
int i;
for (i = 0; i < dws->num_cs; i++) {
int cs_gpio = of_get_named_gpio(pdev->dev.of_node,
"cs-gpios", i);
if (cs_gpio == -EPROBE_DEFER) {
ret = cs_gpio;
goto out;
}
if (gpio_is_valid(cs_gpio)) {
ret = devm_gpio_request(&pdev->dev, cs_gpio,
dev_name(&pdev->dev));
if (ret)
goto out;
}
}
}
init_func = device_get_match_data(&pdev->dev);
if (init_func) {
ret = init_func(pdev, dwsmmio);
if (ret)
goto out;
}
ret = dw_spi_add_host(&pdev->dev, dws);
if (ret)
goto out;
platform_set_drvdata(pdev, dwsmmio);
return 0;
out:
clk_disable_unprepare(dwsmmio->clk);
return ret;
}
static int dw_spi_mmio_remove(struct platform_device *pdev)
{
struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev);
dw_spi_remove_host(&dwsmmio->dws);
clk_disable_unprepare(dwsmmio->clk);
return 0;
}
static const struct of_device_id dw_spi_mmio_of_match[] = {
{ .compatible = "snps,dw-apb-ssi", },
{ .compatible = "mscc,ocelot-spi", .data = dw_spi_mscc_init},
{ /* end of table */}
};
MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);
static struct platform_driver dw_spi_mmio_driver = {
.probe = dw_spi_mmio_probe,
.remove = dw_spi_mmio_remove,
.driver = {
.name = DRIVER_NAME,
.of_match_table = dw_spi_mmio_of_match,
},
};
module_platform_driver(dw_spi_mmio_driver);
MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>");
MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core");
MODULE_LICENSE("GPL v2");
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