diff options
Diffstat (limited to 'drivers/spi/spi-slave-mt27xx.c')
| -rw-r--r-- | drivers/spi/spi-slave-mt27xx.c | 543 |
1 files changed, 543 insertions, 0 deletions
diff --git a/drivers/spi/spi-slave-mt27xx.c b/drivers/spi/spi-slave-mt27xx.c new file mode 100644 index 000000000..44edaa360 --- /dev/null +++ b/drivers/spi/spi-slave-mt27xx.c @@ -0,0 +1,543 @@ +// 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; + 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); + mdata->dev = &pdev->dev; + mdata->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(mdata->base)) { + ret = PTR_ERR(mdata->base); + goto err_put_ctlr; + } + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + 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"); |