// SPDX-License-Identifier: GPL-2.0-only
/*
* Memory-mapped interface driver for DW SPI Core
*
* Copyright (c) 2010, Octasic semiconductor.
*/
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.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_platform.h>
#include <linux/acpi.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include "spi-dw.h"
#define DRIVER_NAME "dw_spi_mmio"
struct dw_spi_mmio {
struct dw_spi dws;
struct clk *clk;
struct clk *pclk;
void *priv;
struct reset_control *rstc;
};
#define MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL 0x24
#define OCELOT_IF_SI_OWNER_OFFSET 4
#define JAGUAR2_IF_SI_OWNER_OFFSET 6
#define MSCC_IF_SI_OWNER_MASK GENMASK(1, 0)
#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)
#define SPARX5_FORCE_ENA 0xa4
#define SPARX5_FORCE_VAL 0xa8
struct dw_spi_mscc {
struct regmap *syscon;
void __iomem *spi_mst; /* Not sparx5 */
};
/*
* Elba SoC does not use ssi, pin override is used for cs 0,1 and
* gpios for cs 2,3 as defined in the device tree.
*
* cs: | 1 0
* bit: |---3-------2-------1-------0
* | cs1 cs1_ovr cs0 cs0_ovr
*/
#define ELBA_SPICS_REG 0x2468
#define ELBA_SPICS_OFFSET(cs) ((cs) << 1)
#define ELBA_SPICS_MASK(cs) (GENMASK(1, 0) << ELBA_SPICS_OFFSET(cs))
#define ELBA_SPICS_SET(cs, val) \
((((val) << 1) | BIT(0)) << ELBA_SPICS_OFFSET(cs))
/*
* 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 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_controller_get_devdata(spi->controller);
struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws);
struct dw_spi_mscc *dwsmscc = dwsmmio->priv;
u32 cs = spi_get_chipselect(spi, 0);
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,
const char *cpu_syscon, u32 if_si_owner_offset)
{
struct dw_spi_mscc *dwsmscc;
dwsmscc = devm_kzalloc(&pdev->dev, sizeof(*dwsmscc), GFP_KERNEL);
if (!dwsmscc)
return -ENOMEM;
dwsmscc->spi_mst = devm_platform_ioremap_resource(pdev, 1);
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(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,
MSCC_IF_SI_OWNER_MASK << if_si_owner_offset,
MSCC_IF_SI_OWNER_SIMC << if_si_owner_offset);
dwsmmio->dws.set_cs = dw_spi_mscc_set_cs;
dwsmmio->priv = dwsmscc;
return 0;
}
static int dw_spi_mscc_ocelot_init(struct platform_device *pdev,
struct dw_spi_mmio *dwsmmio)
{
return dw_spi_mscc_init(pdev, dwsmmio, "mscc,ocelot-cpu-syscon",
OCELOT_IF_SI_OWNER_OFFSET);
}
static int dw_spi_mscc_jaguar2_init(struct platform_device *pdev,
struct dw_spi_mmio *dwsmmio)
{
return dw_spi_mscc_init(pdev, dwsmmio, "mscc,jaguar2-cpu-syscon",
JAGUAR2_IF_SI_OWNER_OFFSET);
}
/*
* 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 driven by a CS override
* register. enable is an active low signal.
*/
static void dw_spi_sparx5_set_cs(struct spi_device *spi, bool enable)
{
struct dw_spi *dws = spi_controller_get_devdata(spi->controller);
struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws);
struct dw_spi_mscc *dwsmscc = dwsmmio->priv;
u8 cs = spi_get_chipselect(spi, 0);
if (!enable) {
/* CS override drive enable */
regmap_write(dwsmscc->syscon, SPARX5_FORCE_ENA, 1);
/* Now set CSx enabled */
regmap_write(dwsmscc->syscon, SPARX5_FORCE_VAL, ~BIT(cs));
/* Allow settle */
usleep_range(1, 5);
} else {
/* CS value */
regmap_write(dwsmscc->syscon, SPARX5_FORCE_VAL, ~0);
/* Allow settle */
usleep_range(1, 5);
/* CS override drive disable */
regmap_write(dwsmscc->syscon, SPARX5_FORCE_ENA, 0);
}
dw_spi_set_cs(spi, enable);
}
static int dw_spi_mscc_sparx5_init(struct platform_device *pdev,
struct dw_spi_mmio *dwsmmio)
{
const char *syscon_name = "microchip,sparx5-cpu-syscon";
struct device *dev = &pdev->dev;
struct dw_spi_mscc *dwsmscc;
if (!IS_ENABLED(CONFIG_SPI_MUX)) {
dev_err(dev, "This driver needs CONFIG_SPI_MUX\n");
return -EOPNOTSUPP;
}
dwsmscc = devm_kzalloc(dev, sizeof(*dwsmscc), GFP_KERNEL);
if (!dwsmscc)
return -ENOMEM;
dwsmscc->syscon =
syscon_regmap_lookup_by_compatible(syscon_name);
if (IS_ERR(dwsmscc->syscon)) {
dev_err(dev, "No syscon map %s\n", syscon_name);
return PTR_ERR(dwsmscc->syscon);
}
dwsmmio->dws.set_cs = dw_spi_sparx5_set_cs;
dwsmmio->priv = dwsmscc;
return 0;
}
static int dw_spi_alpine_init(struct platform_device *pdev,
struct dw_spi_mmio *dwsmmio)
{
dwsmmio->dws.caps = DW_SPI_CAP_CS_OVERRIDE;
return 0;
}
static int dw_spi_pssi_init(struct platform_device *pdev,
struct dw_spi_mmio *dwsmmio)
{
dw_spi_dma_setup_generic(&dwsmmio->dws);
return 0;
}
static int dw_spi_hssi_init(struct platform_device *pdev,
struct dw_spi_mmio *dwsmmio)
{
dwsmmio->dws.ip = DW_HSSI_ID;
dw_spi_dma_setup_generic(&dwsmmio->dws);
return 0;
}
static int dw_spi_intel_init(struct platform_device *pdev,
struct dw_spi_mmio *dwsmmio)
{
dwsmmio->dws.ip = DW_HSSI_ID;
return 0;
}
/*
* DMA-based mem ops are not configured for this device and are not tested.
*/
static int dw_spi_mountevans_imc_init(struct platform_device *pdev,
struct dw_spi_mmio *dwsmmio)
{
/*
* The Intel Mount Evans SoC's Integrated Management Complex DW
* apb_ssi_v4.02a controller has an errata where a full TX FIFO can
* result in data corruption. The suggested workaround is to never
* completely fill the FIFO. The TX FIFO has a size of 32 so the
* fifo_len is set to 31.
*/
dwsmmio->dws.fifo_len = 31;
return 0;
}
static int dw_spi_canaan_k210_init(struct platform_device *pdev,
struct dw_spi_mmio *dwsmmio)
{
/*
* The Canaan Kendryte K210 SoC DW apb_ssi v4 spi controller is
* documented to have a 32 word deep TX and RX FIFO, which
* spi_hw_init() detects. However, when the RX FIFO is filled up to
* 32 entries (RXFLR = 32), an RX FIFO overrun error occurs. Avoid this
* problem by force setting fifo_len to 31.
*/
dwsmmio->dws.fifo_len = 31;
return 0;
}
static void dw_spi_elba_override_cs(struct regmap *syscon, int cs, int enable)
{
regmap_update_bits(syscon, ELBA_SPICS_REG, ELBA_SPICS_MASK(cs),
ELBA_SPICS_SET(cs, enable));
}
static void dw_spi_elba_set_cs(struct spi_device *spi, bool enable)
{
struct dw_spi *dws = spi_controller_get_devdata(spi->controller);
struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws);
struct regmap *syscon = dwsmmio->priv;
u8 cs;
cs = spi_get_chipselect(spi, 0);
if (cs < 2)
dw_spi_elba_override_cs(syscon, spi_get_chipselect(spi, 0), enable);
/*
* The DW SPI controller needs a native CS bit selected to start
* the serial engine.
*/
spi_set_chipselect(spi, 0, 0);
dw_spi_set_cs(spi, enable);
spi_set_chipselect(spi, 0, cs);
}
static int dw_spi_elba_init(struct platform_device *pdev,
struct dw_spi_mmio *dwsmmio)
{
struct regmap *syscon;
syscon = syscon_regmap_lookup_by_phandle(dev_of_node(&pdev->dev),
"amd,pensando-elba-syscon");
if (IS_ERR(syscon))
return dev_err_probe(&pdev->dev, PTR_ERR(syscon),
"syscon regmap lookup failed\n");
dwsmmio->priv = syscon;
dwsmmio->dws.set_cs = dw_spi_elba_set_cs;
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 resource *mem;
struct dw_spi *dws;
int ret;
if (device_property_read_bool(&pdev->dev, "spi-slave")) {
dev_warn(&pdev->dev, "spi-slave is not yet supported\n");
return -ENODEV;
}
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 */
dws->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &mem);
if (IS_ERR(dws->regs))
return PTR_ERR(dws->regs);
dws->paddr = mem->start;
dws->irq = platform_get_irq(pdev, 0);
if (dws->irq < 0)
return dws->irq; /* -ENXIO */
dwsmmio->clk = devm_clk_get_enabled(&pdev->dev, NULL);
if (IS_ERR(dwsmmio->clk))
return PTR_ERR(dwsmmio->clk);
/* Optional clock needed to access the registers */
dwsmmio->pclk = devm_clk_get_optional_enabled(&pdev->dev, "pclk");
if (IS_ERR(dwsmmio->pclk))
return PTR_ERR(dwsmmio->pclk);
/* find an optional reset controller */
dwsmmio->rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, "spi");
if (IS_ERR(dwsmmio->rstc))
return PTR_ERR(dwsmmio->rstc);
reset_control_deassert(dwsmmio->rstc);
dws->bus_num = pdev->id;
dws->max_freq = clk_get_rate(dwsmmio->clk);
if (device_property_read_u32(&pdev->dev, "reg-io-width",
&dws->reg_io_width))
dws->reg_io_width = 4;
/* Rely on the auto-detection if no property specified */
device_property_read_u32(&pdev->dev, "num-cs", &dws->num_cs);
init_func = device_get_match_data(&pdev->dev);
if (init_func) {
ret = init_func(pdev, dwsmmio);
if (ret)
goto out_reset;
}
pm_runtime_enable(&pdev->dev);
ret = dw_spi_add_host(&pdev->dev, dws);
if (ret)
goto out;
platform_set_drvdata(pdev, dwsmmio);
return 0;
out:
pm_runtime_disable(&pdev->dev);
out_reset:
reset_control_assert(dwsmmio->rstc);
return ret;
}
static void dw_spi_mmio_remove(struct platform_device *pdev)
{
struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev);
dw_spi_remove_host(&dwsmmio->dws);
pm_runtime_disable(&pdev->dev);
reset_control_assert(dwsmmio->rstc);
}
static const struct of_device_id dw_spi_mmio_of_match[] = {
{ .compatible = "snps,dw-apb-ssi", .data = dw_spi_pssi_init},
{ .compatible = "mscc,ocelot-spi", .data = dw_spi_mscc_ocelot_init},
{ .compatible = "mscc,jaguar2-spi", .data = dw_spi_mscc_jaguar2_init},
{ .compatible = "amazon,alpine-dw-apb-ssi", .data = dw_spi_alpine_init},
{ .compatible = "renesas,rzn1-spi", .data = dw_spi_pssi_init},
{ .compatible = "snps,dwc-ssi-1.01a", .data = dw_spi_hssi_init},
{ .compatible = "intel,keembay-ssi", .data = dw_spi_intel_init},
{
.compatible = "intel,mountevans-imc-ssi",
.data = dw_spi_mountevans_imc_init,
},
{ .compatible = "microchip,sparx5-spi", dw_spi_mscc_sparx5_init},
{ .compatible = "canaan,k210-spi", dw_spi_canaan_k210_init},
{ .compatible = "amd,pensando-elba-spi", .data = dw_spi_elba_init},
{ /* end of table */}
};
MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);
#ifdef CONFIG_ACPI
static const struct acpi_device_id dw_spi_mmio_acpi_match[] = {
{"HISI0173", (kernel_ulong_t)dw_spi_pssi_init},
{},
};
MODULE_DEVICE_TABLE(acpi, dw_spi_mmio_acpi_match);
#endif
static struct platform_driver dw_spi_mmio_driver = {
.probe = dw_spi_mmio_probe,
.remove_new = dw_spi_mmio_remove,
.driver = {
.name = DRIVER_NAME,
.of_match_table = dw_spi_mmio_of_match,
.acpi_match_table = ACPI_PTR(dw_spi_mmio_acpi_match),
},
};
module_platform_driver(dw_spi_mmio_driver);
MODULE_AUTHOR("Jean-Hugues Deschenes <[email protected]>");
MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS(SPI_DW_CORE);
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