spi-slave-mt27xx.c
// SPDX-License-Identifier: GPL-2.0+
// Copyright (c) 2018 MediaTek Inc.
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/spi/spi.h>
#define SPIS_IRQ_EN_REG 0x0
#define SPIS_IRQ_CLR_REG 0x4
#define SPIS_IRQ_ST_REG 0x8
#define SPIS_IRQ_MASK_REG 0xc
#define SPIS_CFG_REG 0x10
#define SPIS_RX_DATA_REG 0x14
#define SPIS_TX_DATA_REG 0x18
#define SPIS_RX_DST_REG 0x1c
#define SPIS_TX_SRC_REG 0x20
#define SPIS_DMA_CFG_REG 0x30
#define SPIS_SOFT_RST_REG 0x40
/* SPIS_IRQ_EN_REG */
#define DMA_DONE_EN BIT(7)
#define DATA_DONE_EN BIT(2)
#define RSTA_DONE_EN BIT(1)
#define CMD_INVALID_EN BIT(0)
/* SPIS_IRQ_ST_REG */
#define DMA_DONE_ST BIT(7)
#define DATA_DONE_ST BIT(2)
#define RSTA_DONE_ST BIT(1)
#define CMD_INVALID_ST BIT(0)
/* SPIS_IRQ_MASK_REG */
#define DMA_DONE_MASK BIT(7)
#define DATA_DONE_MASK BIT(2)
#define RSTA_DONE_MASK BIT(1)
#define CMD_INVALID_MASK BIT(0)
/* SPIS_CFG_REG */
#define SPIS_TX_ENDIAN BIT(7)
#define SPIS_RX_ENDIAN BIT(6)
#define SPIS_TXMSBF BIT(5)
#define SPIS_RXMSBF BIT(4)
#define SPIS_CPHA BIT(3)
#define SPIS_CPOL BIT(2)
#define SPIS_TX_EN BIT(1)
#define SPIS_RX_EN BIT(0)
/* SPIS_DMA_CFG_REG */
#define TX_DMA_TRIG_EN BIT(31)
#define TX_DMA_EN BIT(30)
#define RX_DMA_EN BIT(29)
#define TX_DMA_LEN 0xfffff
/* SPIS_SOFT_RST_REG */
#define SPIS_DMA_ADDR_EN BIT(1)
#define SPIS_SOFT_RST BIT(0)
#define MTK_SPI_SLAVE_MAX_FIFO_SIZE 512U
struct mtk_spi_slave {
struct device *dev;
void __iomem *base;
struct clk *spi_clk;
struct completion xfer_done;
struct spi_transfer *cur_transfer;
bool slave_aborted;
};
static const struct of_device_id mtk_spi_slave_of_match[] = {
{ .compatible = "mediatek,mt2712-spi-slave", },
{}
};
MODULE_DEVICE_TABLE(of, mtk_spi_slave_of_match);
static void mtk_spi_slave_disable_dma(struct mtk_spi_slave *mdata)
{
u32 reg_val;
reg_val = readl(mdata->base + SPIS_DMA_CFG_REG);
reg_val &= ~RX_DMA_EN;
reg_val &= ~TX_DMA_EN;
writel(reg_val, mdata->base + SPIS_DMA_CFG_REG);
}
static void mtk_spi_slave_disable_xfer(struct mtk_spi_slave *mdata)
{
u32 reg_val;
reg_val = readl(mdata->base + SPIS_CFG_REG);
reg_val &= ~SPIS_TX_EN;
reg_val &= ~SPIS_RX_EN;
writel(reg_val, mdata->base + SPIS_CFG_REG);
}
static int mtk_spi_slave_wait_for_completion(struct mtk_spi_slave *mdata)
{
if (wait_for_completion_interruptible(&mdata->xfer_done) ||
mdata->slave_aborted) {
dev_err(mdata->dev, "interrupted\n");
return -EINTR;
}
return 0;
}
static int mtk_spi_slave_prepare_message(struct spi_controller *ctlr,
struct spi_message *msg)
{
struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
struct spi_device *spi = msg->spi;
bool cpha, cpol;
u32 reg_val;
cpha = spi->mode & SPI_CPHA ? 1 : 0;
cpol = spi->mode & SPI_CPOL ? 1 : 0;
reg_val = readl(mdata->base + SPIS_CFG_REG);
if (cpha)
reg_val |= SPIS_CPHA;
else
reg_val &= ~SPIS_CPHA;
if (cpol)
reg_val |= SPIS_CPOL;
else
reg_val &= ~SPIS_CPOL;
if (spi->mode & SPI_LSB_FIRST)
reg_val &= ~(SPIS_TXMSBF | SPIS_RXMSBF);
else
reg_val |= SPIS_TXMSBF | SPIS_RXMSBF;
reg_val &= ~SPIS_TX_ENDIAN;
reg_val &= ~SPIS_RX_ENDIAN;
writel(reg_val, mdata->base + SPIS_CFG_REG);
return 0;
}
static int mtk_spi_slave_fifo_transfer(struct spi_controller *ctlr,
struct spi_device *spi,
struct spi_transfer *xfer)
{
struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
int reg_val, cnt, remainder, ret;
writel(SPIS_SOFT_RST, mdata->base + SPIS_SOFT_RST_REG);
reg_val = readl(mdata->base + SPIS_CFG_REG);
if (xfer->rx_buf)
reg_val |= SPIS_RX_EN;
if (xfer->tx_buf)
reg_val |= SPIS_TX_EN;
writel(reg_val, mdata->base + SPIS_CFG_REG);
cnt = xfer->len / 4;
if (xfer->tx_buf)
iowrite32_rep(mdata->base + SPIS_TX_DATA_REG,
xfer->tx_buf, cnt);
remainder = xfer->len % 4;
if (xfer->tx_buf && remainder > 0) {
reg_val = 0;
memcpy(®_val, xfer->tx_buf + cnt * 4, remainder);
writel(reg_val, mdata->base + SPIS_TX_DATA_REG);
}
ret = mtk_spi_slave_wait_for_completion(mdata);
if (ret) {
mtk_spi_slave_disable_xfer(mdata);
writel(SPIS_SOFT_RST, mdata->base + SPIS_SOFT_RST_REG);
}
return ret;
}
static int mtk_spi_slave_dma_transfer(struct spi_controller *ctlr,
struct spi_device *spi,
struct spi_transfer *xfer)
{
struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
struct device *dev = mdata->dev;
int reg_val, ret;
writel(SPIS_SOFT_RST, mdata->base + SPIS_SOFT_RST_REG);
if (xfer->tx_buf) {
/* tx_buf is a const void* where we need a void * for
* the dma mapping
*/
void *nonconst_tx = (void *)xfer->tx_buf;
xfer->tx_dma = dma_map_single(dev, nonconst_tx,
xfer->len, DMA_TO_DEVICE);
if (dma_mapping_error(dev, xfer->tx_dma)) {
ret = -ENOMEM;
goto disable_transfer;
}
}
if (xfer->rx_buf) {
xfer->rx_dma = dma_map_single(dev, xfer->rx_buf,
xfer->len, DMA_FROM_DEVICE);
if (dma_mapping_error(dev, xfer->rx_dma)) {
ret = -ENOMEM;
goto unmap_txdma;
}
}
writel(xfer->tx_dma, mdata->base + SPIS_TX_SRC_REG);
writel(xfer->rx_dma, mdata->base + SPIS_RX_DST_REG);
writel(SPIS_DMA_ADDR_EN, mdata->base + SPIS_SOFT_RST_REG);
/* enable config reg tx rx_enable */
reg_val = readl(mdata->base + SPIS_CFG_REG);
if (xfer->tx_buf)
reg_val |= SPIS_TX_EN;
if (xfer->rx_buf)
reg_val |= SPIS_RX_EN;
writel(reg_val, mdata->base + SPIS_CFG_REG);
/* config dma */
reg_val = 0;
reg_val |= (xfer->len - 1) & TX_DMA_LEN;
writel(reg_val, mdata->base + SPIS_DMA_CFG_REG);
reg_val = readl(mdata->base + SPIS_DMA_CFG_REG);
if (xfer->tx_buf)
reg_val |= TX_DMA_EN;
if (xfer->rx_buf)
reg_val |= RX_DMA_EN;
reg_val |= TX_DMA_TRIG_EN;
writel(reg_val, mdata->base + SPIS_DMA_CFG_REG);
ret = mtk_spi_slave_wait_for_completion(mdata);
if (ret)
goto unmap_rxdma;
return 0;
unmap_rxdma:
if (xfer->rx_buf)
dma_unmap_single(dev, xfer->rx_dma,
xfer->len, DMA_FROM_DEVICE);
unmap_txdma:
if (xfer->tx_buf)
dma_unmap_single(dev, xfer->tx_dma,
xfer->len, DMA_TO_DEVICE);
disable_transfer:
mtk_spi_slave_disable_dma(mdata);
mtk_spi_slave_disable_xfer(mdata);
writel(SPIS_SOFT_RST, mdata->base + SPIS_SOFT_RST_REG);
return ret;
}
static int mtk_spi_slave_transfer_one(struct spi_controller *ctlr,
struct spi_device *spi,
struct spi_transfer *xfer)
{
struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
reinit_completion(&mdata->xfer_done);
mdata->slave_aborted = false;
mdata->cur_transfer = xfer;
if (xfer->len > MTK_SPI_SLAVE_MAX_FIFO_SIZE)
return mtk_spi_slave_dma_transfer(ctlr, spi, xfer);
else
return mtk_spi_slave_fifo_transfer(ctlr, spi, xfer);
}
static int mtk_spi_slave_setup(struct spi_device *spi)
{
struct mtk_spi_slave *mdata = spi_controller_get_devdata(spi->master);
u32 reg_val;
reg_val = DMA_DONE_EN | DATA_DONE_EN |
RSTA_DONE_EN | CMD_INVALID_EN;
writel(reg_val, mdata->base + SPIS_IRQ_EN_REG);
reg_val = DMA_DONE_MASK | DATA_DONE_MASK |
RSTA_DONE_MASK | CMD_INVALID_MASK;
writel(reg_val, mdata->base + SPIS_IRQ_MASK_REG);
mtk_spi_slave_disable_dma(mdata);
mtk_spi_slave_disable_xfer(mdata);
return 0;
}
static int mtk_slave_abort(struct spi_controller *ctlr)
{
struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
mdata->slave_aborted = true;
complete(&mdata->xfer_done);
return 0;
}
static irqreturn_t mtk_spi_slave_interrupt(int irq, void *dev_id)
{
struct spi_controller *ctlr = dev_id;
struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
struct spi_transfer *trans = mdata->cur_transfer;
u32 int_status, reg_val, cnt, remainder;
int_status = readl(mdata->base + SPIS_IRQ_ST_REG);
writel(int_status, mdata->base + SPIS_IRQ_CLR_REG);
if (!trans)
return IRQ_NONE;
if ((int_status & DMA_DONE_ST) &&
((int_status & DATA_DONE_ST) ||
(int_status & RSTA_DONE_ST))) {
writel(SPIS_SOFT_RST, mdata->base + SPIS_SOFT_RST_REG);
if (trans->tx_buf)
dma_unmap_single(mdata->dev, trans->tx_dma,
trans->len, DMA_TO_DEVICE);
if (trans->rx_buf)
dma_unmap_single(mdata->dev, trans->rx_dma,
trans->len, DMA_FROM_DEVICE);
mtk_spi_slave_disable_dma(mdata);
mtk_spi_slave_disable_xfer(mdata);
}
if ((!(int_status & DMA_DONE_ST)) &&
((int_status & DATA_DONE_ST) ||
(int_status & RSTA_DONE_ST))) {
cnt = trans->len / 4;
if (trans->rx_buf)
ioread32_rep(mdata->base + SPIS_RX_DATA_REG,
trans->rx_buf, cnt);
remainder = trans->len % 4;
if (trans->rx_buf && remainder > 0) {
reg_val = readl(mdata->base + SPIS_RX_DATA_REG);
memcpy(trans->rx_buf + (cnt * 4),
®_val, remainder);
}
mtk_spi_slave_disable_xfer(mdata);
}
if (int_status & CMD_INVALID_ST) {
dev_warn(&ctlr->dev, "cmd invalid\n");
return IRQ_NONE;
}
mdata->cur_transfer = NULL;
complete(&mdata->xfer_done);
return IRQ_HANDLED;
}
static int mtk_spi_slave_probe(struct platform_device *pdev)
{
struct spi_controller *ctlr;
struct mtk_spi_slave *mdata;
struct resource *res;
int irq, ret;
ctlr = spi_alloc_slave(&pdev->dev, sizeof(*mdata));
if (!ctlr) {
dev_err(&pdev->dev, "failed to alloc spi slave\n");
return -ENOMEM;
}
ctlr->auto_runtime_pm = true;
ctlr->dev.of_node = pdev->dev.of_node;
ctlr->mode_bits = SPI_CPOL | SPI_CPHA;
ctlr->mode_bits |= SPI_LSB_FIRST;
ctlr->prepare_message = mtk_spi_slave_prepare_message;
ctlr->transfer_one = mtk_spi_slave_transfer_one;
ctlr->setup = mtk_spi_slave_setup;
ctlr->slave_abort = mtk_slave_abort;
mdata = spi_controller_get_devdata(ctlr);
platform_set_drvdata(pdev, ctlr);
init_completion(&mdata->xfer_done);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
ret = -ENODEV;
dev_err(&pdev->dev, "failed to determine base address\n");
goto err_put_ctlr;
}
mdata->dev = &pdev->dev;
mdata->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(mdata->base)) {
ret = PTR_ERR(mdata->base);
goto err_put_ctlr;
}
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "failed to get irq (%d)\n", irq);
ret = irq;
goto err_put_ctlr;
}
ret = devm_request_irq(&pdev->dev, irq, mtk_spi_slave_interrupt,
IRQF_TRIGGER_NONE, dev_name(&pdev->dev), ctlr);
if (ret) {
dev_err(&pdev->dev, "failed to register irq (%d)\n", ret);
goto err_put_ctlr;
}
mdata->spi_clk = devm_clk_get(&pdev->dev, "spi");
if (IS_ERR(mdata->spi_clk)) {
ret = PTR_ERR(mdata->spi_clk);
dev_err(&pdev->dev, "failed to get spi-clk: %d\n", ret);
goto err_put_ctlr;
}
ret = clk_prepare_enable(mdata->spi_clk);
if (ret < 0) {
dev_err(&pdev->dev, "failed to enable spi_clk (%d)\n", ret);
goto err_put_ctlr;
}
pm_runtime_enable(&pdev->dev);
ret = devm_spi_register_controller(&pdev->dev, ctlr);
if (ret) {
dev_err(&pdev->dev,
"failed to register slave controller(%d)\n", ret);
clk_disable_unprepare(mdata->spi_clk);
goto err_disable_runtime_pm;
}
clk_disable_unprepare(mdata->spi_clk);
return 0;
err_disable_runtime_pm:
pm_runtime_disable(&pdev->dev);
err_put_ctlr:
spi_controller_put(ctlr);
return ret;
}
static int mtk_spi_slave_remove(struct platform_device *pdev)
{
pm_runtime_disable(&pdev->dev);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int mtk_spi_slave_suspend(struct device *dev)
{
struct spi_controller *ctlr = dev_get_drvdata(dev);
struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
int ret;
ret = spi_controller_suspend(ctlr);
if (ret)
return ret;
if (!pm_runtime_suspended(dev))
clk_disable_unprepare(mdata->spi_clk);
return ret;
}
static int mtk_spi_slave_resume(struct device *dev)
{
struct spi_controller *ctlr = dev_get_drvdata(dev);
struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
int ret;
if (!pm_runtime_suspended(dev)) {
ret = clk_prepare_enable(mdata->spi_clk);
if (ret < 0) {
dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
return ret;
}
}
ret = spi_controller_resume(ctlr);
if (ret < 0)
clk_disable_unprepare(mdata->spi_clk);
return ret;
}
#endif /* CONFIG_PM_SLEEP */
#ifdef CONFIG_PM
static int mtk_spi_slave_runtime_suspend(struct device *dev)
{
struct spi_controller *ctlr = dev_get_drvdata(dev);
struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
clk_disable_unprepare(mdata->spi_clk);
return 0;
}
static int mtk_spi_slave_runtime_resume(struct device *dev)
{
struct spi_controller *ctlr = dev_get_drvdata(dev);
struct mtk_spi_slave *mdata = spi_controller_get_devdata(ctlr);
int ret;
ret = clk_prepare_enable(mdata->spi_clk);
if (ret < 0) {
dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
return ret;
}
return 0;
}
#endif /* CONFIG_PM */
static const struct dev_pm_ops mtk_spi_slave_pm = {
SET_SYSTEM_SLEEP_PM_OPS(mtk_spi_slave_suspend, mtk_spi_slave_resume)
SET_RUNTIME_PM_OPS(mtk_spi_slave_runtime_suspend,
mtk_spi_slave_runtime_resume, NULL)
};
static struct platform_driver mtk_spi_slave_driver = {
.driver = {
.name = "mtk-spi-slave",
.pm = &mtk_spi_slave_pm,
.of_match_table = mtk_spi_slave_of_match,
},
.probe = mtk_spi_slave_probe,
.remove = mtk_spi_slave_remove,
};
module_platform_driver(mtk_spi_slave_driver);
MODULE_DESCRIPTION("MTK SPI Slave Controller driver");
MODULE_AUTHOR("Leilk Liu <leilk.liu@mediatek.com>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:mtk-spi-slave");