diff options
Diffstat (limited to 'kernel/drivers/spi/spi-ti-qspi.c')
-rw-r--r-- | kernel/drivers/spi/spi-ti-qspi.c | 600 |
1 files changed, 600 insertions, 0 deletions
diff --git a/kernel/drivers/spi/spi-ti-qspi.c b/kernel/drivers/spi/spi-ti-qspi.c new file mode 100644 index 000000000..5c0616870 --- /dev/null +++ b/kernel/drivers/spi/spi-ti-qspi.c @@ -0,0 +1,600 @@ +/* + * TI QSPI driver + * + * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com + * Author: Sourav Poddar <sourav.poddar@ti.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GPLv2. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR /PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/delay.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> +#include <linux/omap-dma.h> +#include <linux/platform_device.h> +#include <linux/err.h> +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/pm_runtime.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/pinctrl/consumer.h> + +#include <linux/spi/spi.h> + +struct ti_qspi_regs { + u32 clkctrl; +}; + +struct ti_qspi { + struct completion transfer_complete; + + /* list synchronization */ + struct mutex list_lock; + + struct spi_master *master; + void __iomem *base; + void __iomem *ctrl_base; + void __iomem *mmap_base; + struct clk *fclk; + struct device *dev; + + struct ti_qspi_regs ctx_reg; + + u32 spi_max_frequency; + u32 cmd; + u32 dc; + + bool ctrl_mod; +}; + +#define QSPI_PID (0x0) +#define QSPI_SYSCONFIG (0x10) +#define QSPI_INTR_STATUS_RAW_SET (0x20) +#define QSPI_INTR_STATUS_ENABLED_CLEAR (0x24) +#define QSPI_INTR_ENABLE_SET_REG (0x28) +#define QSPI_INTR_ENABLE_CLEAR_REG (0x2c) +#define QSPI_SPI_CLOCK_CNTRL_REG (0x40) +#define QSPI_SPI_DC_REG (0x44) +#define QSPI_SPI_CMD_REG (0x48) +#define QSPI_SPI_STATUS_REG (0x4c) +#define QSPI_SPI_DATA_REG (0x50) +#define QSPI_SPI_SETUP0_REG (0x54) +#define QSPI_SPI_SWITCH_REG (0x64) +#define QSPI_SPI_SETUP1_REG (0x58) +#define QSPI_SPI_SETUP2_REG (0x5c) +#define QSPI_SPI_SETUP3_REG (0x60) +#define QSPI_SPI_DATA_REG_1 (0x68) +#define QSPI_SPI_DATA_REG_2 (0x6c) +#define QSPI_SPI_DATA_REG_3 (0x70) + +#define QSPI_COMPLETION_TIMEOUT msecs_to_jiffies(2000) + +#define QSPI_FCLK 192000000 + +/* Clock Control */ +#define QSPI_CLK_EN (1 << 31) +#define QSPI_CLK_DIV_MAX 0xffff + +/* Command */ +#define QSPI_EN_CS(n) (n << 28) +#define QSPI_WLEN(n) ((n - 1) << 19) +#define QSPI_3_PIN (1 << 18) +#define QSPI_RD_SNGL (1 << 16) +#define QSPI_WR_SNGL (2 << 16) +#define QSPI_RD_DUAL (3 << 16) +#define QSPI_RD_QUAD (7 << 16) +#define QSPI_INVAL (4 << 16) +#define QSPI_WC_CMD_INT_EN (1 << 14) +#define QSPI_FLEN(n) ((n - 1) << 0) + +/* STATUS REGISTER */ +#define BUSY 0x01 +#define WC 0x02 + +/* INTERRUPT REGISTER */ +#define QSPI_WC_INT_EN (1 << 1) +#define QSPI_WC_INT_DISABLE (1 << 1) + +/* Device Control */ +#define QSPI_DD(m, n) (m << (3 + n * 8)) +#define QSPI_CKPHA(n) (1 << (2 + n * 8)) +#define QSPI_CSPOL(n) (1 << (1 + n * 8)) +#define QSPI_CKPOL(n) (1 << (n * 8)) + +#define QSPI_FRAME 4096 + +#define QSPI_AUTOSUSPEND_TIMEOUT 2000 + +static inline unsigned long ti_qspi_read(struct ti_qspi *qspi, + unsigned long reg) +{ + return readl(qspi->base + reg); +} + +static inline void ti_qspi_write(struct ti_qspi *qspi, + unsigned long val, unsigned long reg) +{ + writel(val, qspi->base + reg); +} + +static int ti_qspi_setup(struct spi_device *spi) +{ + struct ti_qspi *qspi = spi_master_get_devdata(spi->master); + struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg; + int clk_div = 0, ret; + u32 clk_ctrl_reg, clk_rate, clk_mask; + + if (spi->master->busy) { + dev_dbg(qspi->dev, "master busy doing other trasnfers\n"); + return -EBUSY; + } + + if (!qspi->spi_max_frequency) { + dev_err(qspi->dev, "spi max frequency not defined\n"); + return -EINVAL; + } + + clk_rate = clk_get_rate(qspi->fclk); + + clk_div = DIV_ROUND_UP(clk_rate, qspi->spi_max_frequency) - 1; + + if (clk_div < 0) { + dev_dbg(qspi->dev, "clock divider < 0, using /1 divider\n"); + return -EINVAL; + } + + if (clk_div > QSPI_CLK_DIV_MAX) { + dev_dbg(qspi->dev, "clock divider >%d , using /%d divider\n", + QSPI_CLK_DIV_MAX, QSPI_CLK_DIV_MAX + 1); + return -EINVAL; + } + + dev_dbg(qspi->dev, "hz: %d, clock divider %d\n", + qspi->spi_max_frequency, clk_div); + + ret = pm_runtime_get_sync(qspi->dev); + if (ret < 0) { + dev_err(qspi->dev, "pm_runtime_get_sync() failed\n"); + return ret; + } + + clk_ctrl_reg = ti_qspi_read(qspi, QSPI_SPI_CLOCK_CNTRL_REG); + + clk_ctrl_reg &= ~QSPI_CLK_EN; + + /* disable SCLK */ + ti_qspi_write(qspi, clk_ctrl_reg, QSPI_SPI_CLOCK_CNTRL_REG); + + /* enable SCLK */ + clk_mask = QSPI_CLK_EN | clk_div; + ti_qspi_write(qspi, clk_mask, QSPI_SPI_CLOCK_CNTRL_REG); + ctx_reg->clkctrl = clk_mask; + + pm_runtime_mark_last_busy(qspi->dev); + ret = pm_runtime_put_autosuspend(qspi->dev); + if (ret < 0) { + dev_err(qspi->dev, "pm_runtime_put_autosuspend() failed\n"); + return ret; + } + + return 0; +} + +static void ti_qspi_restore_ctx(struct ti_qspi *qspi) +{ + struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg; + + ti_qspi_write(qspi, ctx_reg->clkctrl, QSPI_SPI_CLOCK_CNTRL_REG); +} + +static inline u32 qspi_is_busy(struct ti_qspi *qspi) +{ + u32 stat; + unsigned long timeout = jiffies + QSPI_COMPLETION_TIMEOUT; + + stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG); + while ((stat & BUSY) && time_after(timeout, jiffies)) { + cpu_relax(); + stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG); + } + + WARN(stat & BUSY, "qspi busy\n"); + return stat & BUSY; +} + +static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t) +{ + int wlen, count; + unsigned int cmd; + const u8 *txbuf; + + txbuf = t->tx_buf; + cmd = qspi->cmd | QSPI_WR_SNGL; + count = t->len; + wlen = t->bits_per_word >> 3; /* in bytes */ + + while (count) { + if (qspi_is_busy(qspi)) + return -EBUSY; + + switch (wlen) { + case 1: + dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %02x\n", + cmd, qspi->dc, *txbuf); + writeb(*txbuf, qspi->base + QSPI_SPI_DATA_REG); + break; + case 2: + dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %04x\n", + cmd, qspi->dc, *txbuf); + writew(*((u16 *)txbuf), qspi->base + QSPI_SPI_DATA_REG); + break; + case 4: + dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %08x\n", + cmd, qspi->dc, *txbuf); + writel(*((u32 *)txbuf), qspi->base + QSPI_SPI_DATA_REG); + break; + } + + ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG); + if (!wait_for_completion_timeout(&qspi->transfer_complete, + QSPI_COMPLETION_TIMEOUT)) { + dev_err(qspi->dev, "write timed out\n"); + return -ETIMEDOUT; + } + txbuf += wlen; + count -= wlen; + } + + return 0; +} + +static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t) +{ + int wlen, count; + unsigned int cmd; + u8 *rxbuf; + + rxbuf = t->rx_buf; + cmd = qspi->cmd; + switch (t->rx_nbits) { + case SPI_NBITS_DUAL: + cmd |= QSPI_RD_DUAL; + break; + case SPI_NBITS_QUAD: + cmd |= QSPI_RD_QUAD; + break; + default: + cmd |= QSPI_RD_SNGL; + break; + } + count = t->len; + wlen = t->bits_per_word >> 3; /* in bytes */ + + while (count) { + dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n", cmd, qspi->dc); + if (qspi_is_busy(qspi)) + return -EBUSY; + + ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG); + if (!wait_for_completion_timeout(&qspi->transfer_complete, + QSPI_COMPLETION_TIMEOUT)) { + dev_err(qspi->dev, "read timed out\n"); + return -ETIMEDOUT; + } + switch (wlen) { + case 1: + *rxbuf = readb(qspi->base + QSPI_SPI_DATA_REG); + break; + case 2: + *((u16 *)rxbuf) = readw(qspi->base + QSPI_SPI_DATA_REG); + break; + case 4: + *((u32 *)rxbuf) = readl(qspi->base + QSPI_SPI_DATA_REG); + break; + } + rxbuf += wlen; + count -= wlen; + } + + return 0; +} + +static int qspi_transfer_msg(struct ti_qspi *qspi, struct spi_transfer *t) +{ + int ret; + + if (t->tx_buf) { + ret = qspi_write_msg(qspi, t); + if (ret) { + dev_dbg(qspi->dev, "Error while writing\n"); + return ret; + } + } + + if (t->rx_buf) { + ret = qspi_read_msg(qspi, t); + if (ret) { + dev_dbg(qspi->dev, "Error while reading\n"); + return ret; + } + } + + return 0; +} + +static int ti_qspi_start_transfer_one(struct spi_master *master, + struct spi_message *m) +{ + struct ti_qspi *qspi = spi_master_get_devdata(master); + struct spi_device *spi = m->spi; + struct spi_transfer *t; + int status = 0, ret; + int frame_length; + + /* setup device control reg */ + qspi->dc = 0; + + if (spi->mode & SPI_CPHA) + qspi->dc |= QSPI_CKPHA(spi->chip_select); + if (spi->mode & SPI_CPOL) + qspi->dc |= QSPI_CKPOL(spi->chip_select); + if (spi->mode & SPI_CS_HIGH) + qspi->dc |= QSPI_CSPOL(spi->chip_select); + + frame_length = (m->frame_length << 3) / spi->bits_per_word; + + frame_length = clamp(frame_length, 0, QSPI_FRAME); + + /* setup command reg */ + qspi->cmd = 0; + qspi->cmd |= QSPI_EN_CS(spi->chip_select); + qspi->cmd |= QSPI_FLEN(frame_length); + qspi->cmd |= QSPI_WC_CMD_INT_EN; + + ti_qspi_write(qspi, QSPI_WC_INT_EN, QSPI_INTR_ENABLE_SET_REG); + ti_qspi_write(qspi, qspi->dc, QSPI_SPI_DC_REG); + + mutex_lock(&qspi->list_lock); + + list_for_each_entry(t, &m->transfers, transfer_list) { + qspi->cmd |= QSPI_WLEN(t->bits_per_word); + + ret = qspi_transfer_msg(qspi, t); + if (ret) { + dev_dbg(qspi->dev, "transfer message failed\n"); + mutex_unlock(&qspi->list_lock); + return -EINVAL; + } + + m->actual_length += t->len; + } + + mutex_unlock(&qspi->list_lock); + + m->status = status; + spi_finalize_current_message(master); + + ti_qspi_write(qspi, qspi->cmd | QSPI_INVAL, QSPI_SPI_CMD_REG); + + return status; +} + +static irqreturn_t ti_qspi_isr(int irq, void *dev_id) +{ + struct ti_qspi *qspi = dev_id; + u16 int_stat; + u32 stat; + + irqreturn_t ret = IRQ_HANDLED; + + int_stat = ti_qspi_read(qspi, QSPI_INTR_STATUS_ENABLED_CLEAR); + stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG); + + if (!int_stat) { + dev_dbg(qspi->dev, "No IRQ triggered\n"); + ret = IRQ_NONE; + goto out; + } + + ti_qspi_write(qspi, QSPI_WC_INT_DISABLE, + QSPI_INTR_STATUS_ENABLED_CLEAR); + if (stat & WC) + complete(&qspi->transfer_complete); +out: + return ret; +} + +static int ti_qspi_runtime_resume(struct device *dev) +{ + struct ti_qspi *qspi; + + qspi = dev_get_drvdata(dev); + ti_qspi_restore_ctx(qspi); + + return 0; +} + +static const struct of_device_id ti_qspi_match[] = { + {.compatible = "ti,dra7xxx-qspi" }, + {.compatible = "ti,am4372-qspi" }, + {}, +}; +MODULE_DEVICE_TABLE(of, ti_qspi_match); + +static int ti_qspi_probe(struct platform_device *pdev) +{ + struct ti_qspi *qspi; + struct spi_master *master; + struct resource *r, *res_ctrl, *res_mmap; + struct device_node *np = pdev->dev.of_node; + u32 max_freq; + int ret = 0, num_cs, irq; + + master = spi_alloc_master(&pdev->dev, sizeof(*qspi)); + if (!master) + return -ENOMEM; + + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_DUAL | SPI_RX_QUAD; + + master->flags = SPI_MASTER_HALF_DUPLEX; + master->setup = ti_qspi_setup; + master->auto_runtime_pm = true; + master->transfer_one_message = ti_qspi_start_transfer_one; + master->dev.of_node = pdev->dev.of_node; + master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) | + SPI_BPW_MASK(8); + + if (!of_property_read_u32(np, "num-cs", &num_cs)) + master->num_chipselect = num_cs; + + qspi = spi_master_get_devdata(master); + qspi->master = master; + qspi->dev = &pdev->dev; + platform_set_drvdata(pdev, qspi); + + r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_base"); + if (r == NULL) { + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (r == NULL) { + dev_err(&pdev->dev, "missing platform data\n"); + return -ENODEV; + } + } + + res_mmap = platform_get_resource_byname(pdev, + IORESOURCE_MEM, "qspi_mmap"); + if (res_mmap == NULL) { + res_mmap = platform_get_resource(pdev, IORESOURCE_MEM, 1); + if (res_mmap == NULL) { + dev_err(&pdev->dev, + "memory mapped resource not required\n"); + } + } + + res_ctrl = platform_get_resource_byname(pdev, + IORESOURCE_MEM, "qspi_ctrlmod"); + if (res_ctrl == NULL) { + res_ctrl = platform_get_resource(pdev, IORESOURCE_MEM, 2); + if (res_ctrl == NULL) { + dev_dbg(&pdev->dev, + "control module resources not required\n"); + } + } + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(&pdev->dev, "no irq resource?\n"); + return irq; + } + + mutex_init(&qspi->list_lock); + + qspi->base = devm_ioremap_resource(&pdev->dev, r); + if (IS_ERR(qspi->base)) { + ret = PTR_ERR(qspi->base); + goto free_master; + } + + if (res_ctrl) { + qspi->ctrl_mod = true; + qspi->ctrl_base = devm_ioremap_resource(&pdev->dev, res_ctrl); + if (IS_ERR(qspi->ctrl_base)) { + ret = PTR_ERR(qspi->ctrl_base); + goto free_master; + } + } + + if (res_mmap) { + qspi->mmap_base = devm_ioremap_resource(&pdev->dev, res_mmap); + if (IS_ERR(qspi->mmap_base)) { + ret = PTR_ERR(qspi->mmap_base); + goto free_master; + } + } + + ret = devm_request_irq(&pdev->dev, irq, ti_qspi_isr, 0, + dev_name(&pdev->dev), qspi); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n", + irq); + goto free_master; + } + + qspi->fclk = devm_clk_get(&pdev->dev, "fck"); + if (IS_ERR(qspi->fclk)) { + ret = PTR_ERR(qspi->fclk); + dev_err(&pdev->dev, "could not get clk: %d\n", ret); + } + + init_completion(&qspi->transfer_complete); + + pm_runtime_use_autosuspend(&pdev->dev); + pm_runtime_set_autosuspend_delay(&pdev->dev, QSPI_AUTOSUSPEND_TIMEOUT); + pm_runtime_enable(&pdev->dev); + + if (!of_property_read_u32(np, "spi-max-frequency", &max_freq)) + qspi->spi_max_frequency = max_freq; + + ret = devm_spi_register_master(&pdev->dev, master); + if (ret) + goto free_master; + + return 0; + +free_master: + spi_master_put(master); + return ret; +} + +static int ti_qspi_remove(struct platform_device *pdev) +{ + struct ti_qspi *qspi = platform_get_drvdata(pdev); + int ret; + + ret = pm_runtime_get_sync(qspi->dev); + if (ret < 0) { + dev_err(qspi->dev, "pm_runtime_get_sync() failed\n"); + return ret; + } + + ti_qspi_write(qspi, QSPI_WC_INT_DISABLE, QSPI_INTR_ENABLE_CLEAR_REG); + + pm_runtime_put(qspi->dev); + pm_runtime_disable(&pdev->dev); + + return 0; +} + +static const struct dev_pm_ops ti_qspi_pm_ops = { + .runtime_resume = ti_qspi_runtime_resume, +}; + +static struct platform_driver ti_qspi_driver = { + .probe = ti_qspi_probe, + .remove = ti_qspi_remove, + .driver = { + .name = "ti-qspi", + .pm = &ti_qspi_pm_ops, + .of_match_table = ti_qspi_match, + } +}; + +module_platform_driver(ti_qspi_driver); + +MODULE_AUTHOR("Sourav Poddar <sourav.poddar@ti.com>"); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("TI QSPI controller driver"); +MODULE_ALIAS("platform:ti-qspi"); |