1 files changed, 574 insertions, 0 deletions

diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c
new file mode 100644
index 000000000000..e12d962a289f
--- /dev/null
+++ b/drivers/spi/spi-ti-qspi.c
@@ -0,0 +1,574 @@
+/*
+ * 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;
+
+	/* IRQ synchronization */
+	spinlock_t              lock;
+
+	/* list synchronization */
+	struct mutex            list_lock;
+
+	struct spi_master	*master;
+	void __iomem            *base;
+	struct clk		*fclk;
+	struct device           *dev;
+
+	struct ti_qspi_regs     ctx_reg;
+
+	u32 spi_max_frequency;
+	u32 cmd;
+	u32 dc;
+	u32 stat;
+};
+
+#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 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) {
+		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 int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t)
+{
+	int wlen, count, ret;
+	unsigned int cmd;
+	const u8 *txbuf;
+
+	txbuf = t->tx_buf;
+	cmd = qspi->cmd | QSPI_WR_SNGL;
+	count = t->len;
+	wlen = t->bits_per_word;
+
+	while (count) {
+		switch (wlen) {
+		case 8:
+			dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %02x\n",
+					cmd, qspi->dc, *txbuf);
+			writeb(*txbuf, qspi->base + QSPI_SPI_DATA_REG);
+			ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
+			ret = wait_for_completion_timeout(&qspi->transfer_complete,
+					QSPI_COMPLETION_TIMEOUT);
+			if (ret == 0) {
+				dev_err(qspi->dev, "write timed out\n");
+				return -ETIMEDOUT;
+			}
+			txbuf += 1;
+			count -= 1;
+			break;
+		case 16:
+			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);
+			ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
+			ret = wait_for_completion_timeout(&qspi->transfer_complete,
+				QSPI_COMPLETION_TIMEOUT);
+			if (ret == 0) {
+				dev_err(qspi->dev, "write timed out\n");
+				return -ETIMEDOUT;
+			}
+			txbuf += 2;
+			count -= 2;
+			break;
+		case 32:
+			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);
+			ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
+			ret = wait_for_completion_timeout(&qspi->transfer_complete,
+				QSPI_COMPLETION_TIMEOUT);
+			if (ret == 0) {
+				dev_err(qspi->dev, "write timed out\n");
+				return -ETIMEDOUT;
+			}
+			txbuf += 4;
+			count -= 4;
+			break;
+		}
+	}
+
+	return 0;
+}
+
+static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t)
+{
+	int wlen, count, ret;
+	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;
+
+	while (count) {
+		dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n", cmd, qspi->dc);
+		ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
+		ret = wait_for_completion_timeout(&qspi->transfer_complete,
+				QSPI_COMPLETION_TIMEOUT);
+		if (ret == 0) {
+			dev_err(qspi->dev, "read timed out\n");
+			return -ETIMEDOUT;
+		}
+		switch (wlen) {
+		case 8:
+			*rxbuf = readb(qspi->base + QSPI_SPI_DATA_REG);
+			rxbuf += 1;
+			count -= 1;
+			break;
+		case 16:
+			*((u16 *)rxbuf) = readw(qspi->base + QSPI_SPI_DATA_REG);
+			rxbuf += 2;
+			count -= 2;
+			break;
+		case 32:
+			*((u32 *)rxbuf) = readl(qspi->base + QSPI_SPI_DATA_REG);
+			rxbuf += 4;
+			count -= 4;
+			break;
+		}
+	}
+
+	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;
+
+	irqreturn_t ret = IRQ_HANDLED;
+
+	spin_lock(&qspi->lock);
+
+	int_stat = ti_qspi_read(qspi, QSPI_INTR_STATUS_ENABLED_CLEAR);
+	qspi->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;
+	}
+
+	ret = IRQ_WAKE_THREAD;
+
+	ti_qspi_write(qspi, QSPI_WC_INT_DISABLE, QSPI_INTR_ENABLE_CLEAR_REG);
+	ti_qspi_write(qspi, QSPI_WC_INT_DISABLE,
+				QSPI_INTR_STATUS_ENABLED_CLEAR);
+
+out:
+	spin_unlock(&qspi->lock);
+
+	return ret;
+}
+
+static irqreturn_t ti_qspi_threaded_isr(int this_irq, void *dev_id)
+{
+	struct ti_qspi *qspi = dev_id;
+	unsigned long flags;
+
+	spin_lock_irqsave(&qspi->lock, flags);
+
+	if (qspi->stat & WC)
+		complete(&qspi->transfer_complete);
+
+	spin_unlock_irqrestore(&qspi->lock, flags);
+
+	ti_qspi_write(qspi, QSPI_WC_INT_EN, QSPI_INTR_ENABLE_SET_REG);
+
+	return IRQ_HANDLED;
+}
+
+static int ti_qspi_runtime_resume(struct device *dev)
+{
+	struct ti_qspi      *qspi;
+	struct spi_master       *master;
+
+	master = dev_get_drvdata(dev);
+	qspi = spi_master_get_devdata(master);
+	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;
+	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;
+
+	master->bus_num = -1;
+	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 = BIT(32 - 1) | BIT(16 - 1) | BIT(8 - 1);
+
+	if (!of_property_read_u32(np, "num-cs", &num_cs))
+		master->num_chipselect = num_cs;
+
+	platform_set_drvdata(pdev, master);
+
+	qspi = spi_master_get_devdata(master);
+	qspi->master = master;
+	qspi->dev = &pdev->dev;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "no irq resource?\n");
+		return irq;
+	}
+
+	spin_lock_init(&qspi->lock);
+	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;
+	}
+
+	ret = devm_request_threaded_irq(&pdev->dev, irq, ti_qspi_isr,
+			ti_qspi_threaded_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 = spi_register_master(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);
+
+	spi_unregister_master(qspi->master);
+
+	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,dra7xxx-qspi",
+		.owner	= THIS_MODULE,
+		.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");