[PATCH v3 2/3] spis: mediatek: add spi slave for Mediatek MT2712

Leilk Liu
2018-09-17T02:19:21Z

This patchs add basic spi slave for MT2712.

Signed-off-by: Leilk Liu <leilk.liu@mediatek.com>
---
drivers/spi/Kconfig | 8 +
drivers/spi/Makefile | 1 +
drivers/spi/spi-slave-mt27xx.c | 553 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 562 insertions(+)
create mode 100644 drivers/spi/spi-slave-mt27xx.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 671d078..86ef6a5 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -802,6 +802,14 @@ config SPI_SLAVE
slave protocol handlers.

if SPI_SLAVE
+config SPI_SLAVE_MT27XX
+ tristate "MediaTek SPI slave device"
+ depends on ARCH_MEDIATEK || COMPILE_TEST
+ help
+ This selects the MediaTek(R) SPI slave device driver.
+ If you want to use MediaTek(R) SPI slave interface,
+ say Y or M here.If you are not sure, say N.
+ SPI slave drivers for Mediatek MT27XX series ARM SoCs.

config SPI_SLAVE_TIME
tristate "SPI slave handler reporting boot up time"
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index a90d559..a5e7b3c 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -109,5 +109,6 @@ obj-$(CONFIG_SPI_XTENSA_XTFPGA) += spi-xtensa-xtfpga.o
obj-$(CONFIG_SPI_ZYNQMP_GQSPI) += spi-zynqmp-gqspi.o

# SPI slave protocol handlers
+obj-$(CONFIG_SPI_SLAVE_MT27XX) += spi-slave-mt27xx.o
obj-$(CONFIG_SPI_SLAVE_TIME) += spi-slave-time.o
obj-$(CONFIG_SPI_SLAVE_SYSTEM_CONTROL) += spi-slave-system-control.o
diff --git a/drivers/spi/spi-slave-mt27xx.c b/drivers/spi/spi-slave-mt27xx.c
new file mode 100644
index 0000000..2e59339
--- /dev/null
+++ b/drivers/spi/spi-slave-mt27xx.c
@@ -0,0 +1,553 @@
+// 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;
+
+ /* set the tx/rx endian */
+#ifdef __LITTLE_ENDIAN
+ reg_val &= ~SPIS_TX_ENDIAN;
+ reg_val &= ~SPIS_RX_ENDIAN;
+#else
+ reg_val |= SPIS_TX_ENDIAN;
+ reg_val |= SPIS_RX_ENDIAN;
+#endif
+ 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(&reg_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) {
+ xfer->tx_dma = dma_map_single(dev, (void *)xfer->tx_buf,
+ 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, (void *)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_HANDLED;
+
+ 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),
+ &reg_val, remainder);
+ }
+
+ mtk_spi_slave_disable_xfer(mdata);
+ }
+
+ if (int_status & CMD_INVALID_ST)
+ dev_err(&ctlr->dev, "cmd invalid\n");
+
+ 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");
--
1.7.9.5