Initial import

1 files changed, 512 insertions, 0 deletions

diff --git a/drivers/spi/spi-omap-100k.c b/drivers/spi/spi-omap-100k.c
new file mode 100644
index 000000000..35b332dac
--- /dev/null
+++ b/drivers/spi/spi-omap-100k.c
@@ -0,0 +1,512 @@
+/*
+ * OMAP7xx SPI 100k controller driver
+ * Author: Fabrice Crohas <fcrohas@gmail.com>
+ * from original omap1_mcspi driver
+ *
+ * Copyright (C) 2005, 2006 Nokia Corporation
+ * Author:      Samuel Ortiz <samuel.ortiz@nokia.com> and
+ *              Juha Yrj�l� <juha.yrjola@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+
+#include <linux/spi/spi.h>
+
+#define OMAP1_SPI100K_MAX_FREQ          48000000
+
+#define ICR_SPITAS      (OMAP7XX_ICR_BASE + 0x12)
+
+#define SPI_SETUP1      0x00
+#define SPI_SETUP2      0x02
+#define SPI_CTRL        0x04
+#define SPI_STATUS      0x06
+#define SPI_TX_LSB      0x08
+#define SPI_TX_MSB      0x0a
+#define SPI_RX_LSB      0x0c
+#define SPI_RX_MSB      0x0e
+
+#define SPI_SETUP1_INT_READ_ENABLE      (1UL << 5)
+#define SPI_SETUP1_INT_WRITE_ENABLE     (1UL << 4)
+#define SPI_SETUP1_CLOCK_DIVISOR(x)     ((x) << 1)
+#define SPI_SETUP1_CLOCK_ENABLE         (1UL << 0)
+
+#define SPI_SETUP2_ACTIVE_EDGE_FALLING  (0UL << 0)
+#define SPI_SETUP2_ACTIVE_EDGE_RISING   (1UL << 0)
+#define SPI_SETUP2_NEGATIVE_LEVEL       (0UL << 5)
+#define SPI_SETUP2_POSITIVE_LEVEL       (1UL << 5)
+#define SPI_SETUP2_LEVEL_TRIGGER        (0UL << 10)
+#define SPI_SETUP2_EDGE_TRIGGER         (1UL << 10)
+
+#define SPI_CTRL_SEN(x)                 ((x) << 7)
+#define SPI_CTRL_WORD_SIZE(x)           (((x) - 1) << 2)
+#define SPI_CTRL_WR                     (1UL << 1)
+#define SPI_CTRL_RD                     (1UL << 0)
+
+#define SPI_STATUS_WE                   (1UL << 1)
+#define SPI_STATUS_RD                   (1UL << 0)
+
+/* use PIO for small transfers, avoiding DMA setup/teardown overhead and
+ * cache operations; better heuristics consider wordsize and bitrate.
+ */
+#define DMA_MIN_BYTES                   8
+
+#define SPI_RUNNING	0
+#define SPI_SHUTDOWN	1
+
+struct omap1_spi100k {
+	struct clk              *ick;
+	struct clk              *fck;
+
+	/* Virtual base address of the controller */
+	void __iomem            *base;
+};
+
+struct omap1_spi100k_cs {
+	void __iomem            *base;
+	int                     word_len;
+};
+
+static void spi100k_enable_clock(struct spi_master *master)
+{
+	unsigned int val;
+	struct omap1_spi100k *spi100k = spi_master_get_devdata(master);
+
+	/* enable SPI */
+	val = readw(spi100k->base + SPI_SETUP1);
+	val |= SPI_SETUP1_CLOCK_ENABLE;
+	writew(val, spi100k->base + SPI_SETUP1);
+}
+
+static void spi100k_disable_clock(struct spi_master *master)
+{
+	unsigned int val;
+	struct omap1_spi100k *spi100k = spi_master_get_devdata(master);
+
+	/* disable SPI */
+	val = readw(spi100k->base + SPI_SETUP1);
+	val &= ~SPI_SETUP1_CLOCK_ENABLE;
+	writew(val, spi100k->base + SPI_SETUP1);
+}
+
+static void spi100k_write_data(struct spi_master *master, int len, int data)
+{
+	struct omap1_spi100k *spi100k = spi_master_get_devdata(master);
+
+	/* write 16-bit word, shifting 8-bit data if necessary */
+	if (len <= 8) {
+		data <<= 8;
+		len = 16;
+	}
+
+	spi100k_enable_clock(master);
+	writew(data , spi100k->base + SPI_TX_MSB);
+
+	writew(SPI_CTRL_SEN(0) |
+	       SPI_CTRL_WORD_SIZE(len) |
+	       SPI_CTRL_WR,
+	       spi100k->base + SPI_CTRL);
+
+	/* Wait for bit ack send change */
+	while ((readw(spi100k->base + SPI_STATUS) & SPI_STATUS_WE) != SPI_STATUS_WE)
+		;
+	udelay(1000);
+
+	spi100k_disable_clock(master);
+}
+
+static int spi100k_read_data(struct spi_master *master, int len)
+{
+	int dataH, dataL;
+	struct omap1_spi100k *spi100k = spi_master_get_devdata(master);
+
+	/* Always do at least 16 bits */
+	if (len <= 8)
+		len = 16;
+
+	spi100k_enable_clock(master);
+	writew(SPI_CTRL_SEN(0) |
+	       SPI_CTRL_WORD_SIZE(len) |
+	       SPI_CTRL_RD,
+	       spi100k->base + SPI_CTRL);
+
+	while ((readw(spi100k->base + SPI_STATUS) & SPI_STATUS_RD) != SPI_STATUS_RD)
+		;
+	udelay(1000);
+
+	dataL = readw(spi100k->base + SPI_RX_LSB);
+	dataH = readw(spi100k->base + SPI_RX_MSB);
+	spi100k_disable_clock(master);
+
+	return dataL;
+}
+
+static void spi100k_open(struct spi_master *master)
+{
+	/* get control of SPI */
+	struct omap1_spi100k *spi100k = spi_master_get_devdata(master);
+
+	writew(SPI_SETUP1_INT_READ_ENABLE |
+	       SPI_SETUP1_INT_WRITE_ENABLE |
+	       SPI_SETUP1_CLOCK_DIVISOR(0), spi100k->base + SPI_SETUP1);
+
+	/* configure clock and interrupts */
+	writew(SPI_SETUP2_ACTIVE_EDGE_FALLING |
+	       SPI_SETUP2_NEGATIVE_LEVEL |
+	       SPI_SETUP2_LEVEL_TRIGGER, spi100k->base + SPI_SETUP2);
+}
+
+static void omap1_spi100k_force_cs(struct omap1_spi100k *spi100k, int enable)
+{
+	if (enable)
+		writew(0x05fc, spi100k->base + SPI_CTRL);
+	else
+		writew(0x05fd, spi100k->base + SPI_CTRL);
+}
+
+static unsigned
+omap1_spi100k_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
+{
+	struct omap1_spi100k_cs *cs = spi->controller_state;
+	unsigned int            count, c;
+	int                     word_len;
+
+	count = xfer->len;
+	c = count;
+	word_len = cs->word_len;
+
+	if (word_len <= 8) {
+		u8              *rx;
+		const u8        *tx;
+
+		rx = xfer->rx_buf;
+		tx = xfer->tx_buf;
+		do {
+			c -= 1;
+			if (xfer->tx_buf != NULL)
+				spi100k_write_data(spi->master, word_len, *tx++);
+			if (xfer->rx_buf != NULL)
+				*rx++ = spi100k_read_data(spi->master, word_len);
+		} while (c);
+	} else if (word_len <= 16) {
+		u16             *rx;
+		const u16       *tx;
+
+		rx = xfer->rx_buf;
+		tx = xfer->tx_buf;
+		do {
+			c -= 2;
+			if (xfer->tx_buf != NULL)
+				spi100k_write_data(spi->master, word_len, *tx++);
+			if (xfer->rx_buf != NULL)
+				*rx++ = spi100k_read_data(spi->master, word_len);
+		} while (c);
+	} else if (word_len <= 32) {
+		u32             *rx;
+		const u32       *tx;
+
+		rx = xfer->rx_buf;
+		tx = xfer->tx_buf;
+		do {
+			c -= 4;
+			if (xfer->tx_buf != NULL)
+				spi100k_write_data(spi->master, word_len, *tx);
+			if (xfer->rx_buf != NULL)
+				*rx = spi100k_read_data(spi->master, word_len);
+		} while (c);
+	}
+	return count - c;
+}
+
+/* called only when no transfer is active to this device */
+static int omap1_spi100k_setup_transfer(struct spi_device *spi,
+		struct spi_transfer *t)
+{
+	struct omap1_spi100k *spi100k = spi_master_get_devdata(spi->master);
+	struct omap1_spi100k_cs *cs = spi->controller_state;
+	u8 word_len = spi->bits_per_word;
+
+	if (t != NULL && t->bits_per_word)
+		word_len = t->bits_per_word;
+	if (!word_len)
+		word_len = 8;
+
+	if (spi->bits_per_word > 32)
+		return -EINVAL;
+	cs->word_len = word_len;
+
+	/* SPI init before transfer */
+	writew(0x3e , spi100k->base + SPI_SETUP1);
+	writew(0x00 , spi100k->base + SPI_STATUS);
+	writew(0x3e , spi100k->base + SPI_CTRL);
+
+	return 0;
+}
+
+/* the spi->mode bits understood by this driver: */
+#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
+
+static int omap1_spi100k_setup(struct spi_device *spi)
+{
+	int                     ret;
+	struct omap1_spi100k    *spi100k;
+	struct omap1_spi100k_cs *cs = spi->controller_state;
+
+	spi100k = spi_master_get_devdata(spi->master);
+
+	if (!cs) {
+		cs = devm_kzalloc(&spi->dev, sizeof(*cs), GFP_KERNEL);
+		if (!cs)
+			return -ENOMEM;
+		cs->base = spi100k->base + spi->chip_select * 0x14;
+		spi->controller_state = cs;
+	}
+
+	spi100k_open(spi->master);
+
+	clk_prepare_enable(spi100k->ick);
+	clk_prepare_enable(spi100k->fck);
+
+	ret = omap1_spi100k_setup_transfer(spi, NULL);
+
+	clk_disable_unprepare(spi100k->ick);
+	clk_disable_unprepare(spi100k->fck);
+
+	return ret;
+}
+
+static int omap1_spi100k_transfer_one_message(struct spi_master *master,
+					      struct spi_message *m)
+{
+	struct omap1_spi100k *spi100k = spi_master_get_devdata(master);
+	struct spi_device *spi = m->spi;
+	struct spi_transfer *t = NULL;
+	int cs_active = 0;
+	int par_override = 0;
+	int status = 0;
+
+	list_for_each_entry(t, &m->transfers, transfer_list) {
+		if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
+			status = -EINVAL;
+			break;
+		}
+		if (par_override || t->speed_hz || t->bits_per_word) {
+			par_override = 1;
+			status = omap1_spi100k_setup_transfer(spi, t);
+			if (status < 0)
+				break;
+			if (!t->speed_hz && !t->bits_per_word)
+				par_override = 0;
+		}
+
+		if (!cs_active) {
+			omap1_spi100k_force_cs(spi100k, 1);
+			cs_active = 1;
+		}
+
+		if (t->len) {
+			unsigned count;
+
+			count = omap1_spi100k_txrx_pio(spi, t);
+			m->actual_length += count;
+
+			if (count != t->len) {
+				status = -EIO;
+				break;
+			}
+		}
+
+		if (t->delay_usecs)
+			udelay(t->delay_usecs);
+
+		/* ignore the "leave it on after last xfer" hint */
+
+		if (t->cs_change) {
+			omap1_spi100k_force_cs(spi100k, 0);
+			cs_active = 0;
+		}
+	}
+
+	/* Restore defaults if they were overriden */
+	if (par_override) {
+		par_override = 0;
+		status = omap1_spi100k_setup_transfer(spi, NULL);
+	}
+
+	if (cs_active)
+		omap1_spi100k_force_cs(spi100k, 0);
+
+	m->status = status;
+
+	spi_finalize_current_message(master);
+
+	return status;
+}
+
+static int omap1_spi100k_probe(struct platform_device *pdev)
+{
+	struct spi_master       *master;
+	struct omap1_spi100k    *spi100k;
+	int                     status = 0;
+
+	if (!pdev->id)
+		return -EINVAL;
+
+	master = spi_alloc_master(&pdev->dev, sizeof(*spi100k));
+	if (master == NULL) {
+		dev_dbg(&pdev->dev, "master allocation failed\n");
+		return -ENOMEM;
+	}
+
+	if (pdev->id != -1)
+		master->bus_num = pdev->id;
+
+	master->setup = omap1_spi100k_setup;
+	master->transfer_one_message = omap1_spi100k_transfer_one_message;
+	master->num_chipselect = 2;
+	master->mode_bits = MODEBITS;
+	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
+	master->min_speed_hz = OMAP1_SPI100K_MAX_FREQ/(1<<16);
+	master->max_speed_hz = OMAP1_SPI100K_MAX_FREQ;
+	master->auto_runtime_pm = true;
+
+	spi100k = spi_master_get_devdata(master);
+
+	/*
+	 * The memory region base address is taken as the platform_data.
+	 * You should allocate this with ioremap() before initializing
+	 * the SPI.
+	 */
+	spi100k->base = (void __iomem *)dev_get_platdata(&pdev->dev);
+
+	spi100k->ick = devm_clk_get(&pdev->dev, "ick");
+	if (IS_ERR(spi100k->ick)) {
+		dev_dbg(&pdev->dev, "can't get spi100k_ick\n");
+		status = PTR_ERR(spi100k->ick);
+		goto err;
+	}
+
+	spi100k->fck = devm_clk_get(&pdev->dev, "fck");
+	if (IS_ERR(spi100k->fck)) {
+		dev_dbg(&pdev->dev, "can't get spi100k_fck\n");
+		status = PTR_ERR(spi100k->fck);
+		goto err;
+	}
+
+	status = clk_prepare_enable(spi100k->ick);
+	if (status != 0) {
+		dev_err(&pdev->dev, "failed to enable ick: %d\n", status);
+		goto err;
+	}
+
+	status = clk_prepare_enable(spi100k->fck);
+	if (status != 0) {
+		dev_err(&pdev->dev, "failed to enable fck: %d\n", status);
+		goto err_ick;
+	}
+
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_set_active(&pdev->dev);
+
+	status = devm_spi_register_master(&pdev->dev, master);
+	if (status < 0)
+		goto err_fck;
+
+	return status;
+
+err_fck:
+	clk_disable_unprepare(spi100k->fck);
+err_ick:
+	clk_disable_unprepare(spi100k->ick);
+err:
+	spi_master_put(master);
+	return status;
+}
+
+static int omap1_spi100k_remove(struct platform_device *pdev)
+{
+	struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
+	struct omap1_spi100k *spi100k = spi_master_get_devdata(master);
+
+	pm_runtime_disable(&pdev->dev);
+
+	clk_disable_unprepare(spi100k->fck);
+	clk_disable_unprepare(spi100k->ick);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int omap1_spi100k_runtime_suspend(struct device *dev)
+{
+	struct spi_master *master = spi_master_get(dev_get_drvdata(dev));
+	struct omap1_spi100k *spi100k = spi_master_get_devdata(master);
+
+	clk_disable_unprepare(spi100k->ick);
+	clk_disable_unprepare(spi100k->fck);
+
+	return 0;
+}
+
+static int omap1_spi100k_runtime_resume(struct device *dev)
+{
+	struct spi_master *master = spi_master_get(dev_get_drvdata(dev));
+	struct omap1_spi100k *spi100k = spi_master_get_devdata(master);
+	int ret;
+
+	ret = clk_prepare_enable(spi100k->ick);
+	if (ret != 0) {
+		dev_err(dev, "Failed to enable ick: %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(spi100k->fck);
+	if (ret != 0) {
+		dev_err(dev, "Failed to enable fck: %d\n", ret);
+		clk_disable_unprepare(spi100k->ick);
+		return ret;
+	}
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops omap1_spi100k_pm = {
+	SET_RUNTIME_PM_OPS(omap1_spi100k_runtime_suspend,
+			   omap1_spi100k_runtime_resume, NULL)
+};
+
+static struct platform_driver omap1_spi100k_driver = {
+	.driver = {
+		.name		= "omap1_spi100k",
+		.pm		= &omap1_spi100k_pm,
+	},
+	.probe		= omap1_spi100k_probe,
+	.remove		= omap1_spi100k_remove,
+};
+
+module_platform_driver(omap1_spi100k_driver);
+
+MODULE_DESCRIPTION("OMAP7xx SPI 100k controller driver");
+MODULE_AUTHOR("Fabrice Crohas <fcrohas@gmail.com>");
+MODULE_LICENSE("GPL");