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path: root/drivers/spi/omap_spi_100k.c
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Diffstat (limited to 'drivers/spi/omap_spi_100k.c')
-rw-r--r--drivers/spi/omap_spi_100k.c635
1 files changed, 635 insertions, 0 deletions
diff --git a/drivers/spi/omap_spi_100k.c b/drivers/spi/omap_spi_100k.c
new file mode 100644
index 000000000000..5355d90d1bee
--- /dev/null
+++ b/drivers/spi/omap_spi_100k.c
@@ -0,0 +1,635 @@
+/*
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+#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/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+
+#include <linux/spi/spi.h>
+
+#include <plat/clock.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)
+
+#define WRITE 0
+#define READ 1
+
+
+/* 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 work_struct work;
+
+ /* lock protects queue and registers */
+ spinlock_t lock;
+ struct list_head msg_queue;
+ struct spi_master *master;
+ struct clk *ick;
+ struct clk *fck;
+
+ /* Virtual base address of the controller */
+ void __iomem *base;
+
+ /* State of the SPI */
+ unsigned int state;
+};
+
+struct omap1_spi100k_cs {
+ void __iomem *base;
+ int word_len;
+};
+
+static struct workqueue_struct *omap1_spi100k_wq;
+
+#define MOD_REG_BIT(val, mask, set) do { \
+ if (set) \
+ val |= mask; \
+ else \
+ val &= ~mask; \
+} while (0)
+
+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 */
+ 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);
+
+ 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 *spi100k;
+ struct omap1_spi100k_cs *cs = spi->controller_state;
+ unsigned int count, c;
+ int word_len;
+
+ spi100k = spi_master_get_devdata(spi->master);
+ count = xfer->len;
+ c = count;
+ word_len = cs->word_len;
+
+ /* RX_ONLY mode needs dummy data in TX reg */
+ if (xfer->tx_buf == NULL)
+ spi100k_write_data(spi->master,word_len, 0);
+
+ 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;
+
+ if (spi->bits_per_word < 4 || spi->bits_per_word > 32) {
+ dev_dbg(&spi->dev, "setup: unsupported %d bit words\n",
+ spi->bits_per_word);
+ return -EINVAL;
+ }
+
+ spi100k = spi_master_get_devdata(spi->master);
+
+ if (!cs) {
+ cs = kzalloc(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_enable(spi100k->ick);
+ clk_enable(spi100k->fck);
+
+ ret = omap1_spi100k_setup_transfer(spi, NULL);
+
+ clk_disable(spi100k->ick);
+ clk_disable(spi100k->fck);
+
+ return ret;
+}
+
+static void omap1_spi100k_work(struct work_struct *work)
+{
+ struct omap1_spi100k *spi100k;
+ int status = 0;
+
+ spi100k = container_of(work, struct omap1_spi100k, work);
+ spin_lock_irq(&spi100k->lock);
+
+ clk_enable(spi100k->ick);
+ clk_enable(spi100k->fck);
+
+ /* We only enable one channel at a time -- the one whose message is
+ * at the head of the queue -- although this controller would gladly
+ * arbitrate among multiple channels. This corresponds to "single
+ * channel" master mode. As a side effect, we need to manage the
+ * chipselect with the FORCE bit ... CS != channel enable.
+ */
+ while (!list_empty(&spi100k->msg_queue)) {
+ struct spi_message *m;
+ struct spi_device *spi;
+ struct spi_transfer *t = NULL;
+ int cs_active = 0;
+ struct omap1_spi100k_cs *cs;
+ int par_override = 0;
+
+ m = container_of(spi100k->msg_queue.next, struct spi_message,
+ queue);
+
+ list_del_init(&m->queue);
+ spin_unlock_irq(&spi100k->lock);
+
+ spi = m->spi;
+ cs = spi->controller_state;
+
+ 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;
+
+ /* RX_ONLY mode needs dummy data in TX reg */
+ if (t->tx_buf == NULL)
+ spi100k_write_data(spi->master, 8, 0);
+
+ 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;
+ m->complete(m->context);
+
+ spin_lock_irq(&spi100k->lock);
+ }
+
+ clk_disable(spi100k->ick);
+ clk_disable(spi100k->fck);
+ spin_unlock_irq(&spi100k->lock);
+
+ if (status < 0)
+ printk(KERN_WARNING "spi transfer failed with %d\n", status);
+}
+
+static int omap1_spi100k_transfer(struct spi_device *spi, struct spi_message *m)
+{
+ struct omap1_spi100k *spi100k;
+ unsigned long flags;
+ struct spi_transfer *t;
+
+ m->actual_length = 0;
+ m->status = -EINPROGRESS;
+
+ spi100k = spi_master_get_devdata(spi->master);
+
+ /* Don't accept new work if we're shutting down */
+ if (spi100k->state == SPI_SHUTDOWN)
+ return -ESHUTDOWN;
+
+ /* reject invalid messages and transfers */
+ if (list_empty(&m->transfers) || !m->complete)
+ return -EINVAL;
+
+ list_for_each_entry(t, &m->transfers, transfer_list) {
+ const void *tx_buf = t->tx_buf;
+ void *rx_buf = t->rx_buf;
+ unsigned len = t->len;
+
+ if (t->speed_hz > OMAP1_SPI100K_MAX_FREQ
+ || (len && !(rx_buf || tx_buf))
+ || (t->bits_per_word &&
+ ( t->bits_per_word < 4
+ || t->bits_per_word > 32))) {
+ dev_dbg(&spi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
+ t->speed_hz,
+ len,
+ tx_buf ? "tx" : "",
+ rx_buf ? "rx" : "",
+ t->bits_per_word);
+ return -EINVAL;
+ }
+
+ if (t->speed_hz && t->speed_hz < OMAP1_SPI100K_MAX_FREQ/(1<<16)) {
+ dev_dbg(&spi->dev, "%d Hz max exceeds %d\n",
+ t->speed_hz,
+ OMAP1_SPI100K_MAX_FREQ/(1<<16));
+ return -EINVAL;
+ }
+
+ }
+
+ spin_lock_irqsave(&spi100k->lock, flags);
+ list_add_tail(&m->queue, &spi100k->msg_queue);
+ queue_work(omap1_spi100k_wq, &spi100k->work);
+ spin_unlock_irqrestore(&spi100k->lock, flags);
+
+ return 0;
+}
+
+static int __init omap1_spi100k_reset(struct omap1_spi100k *spi100k)
+{
+ return 0;
+}
+
+static int __devinit 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 = omap1_spi100k_transfer;
+ master->cleanup = NULL;
+ master->num_chipselect = 2;
+ master->mode_bits = MODEBITS;
+
+ dev_set_drvdata(&pdev->dev, master);
+
+ spi100k = spi_master_get_devdata(master);
+ spi100k->master = 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 *) pdev->dev.platform_data;
+
+ INIT_WORK(&spi100k->work, omap1_spi100k_work);
+
+ spin_lock_init(&spi100k->lock);
+ INIT_LIST_HEAD(&spi100k->msg_queue);
+ spi100k->ick = 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 err1;
+ }
+
+ spi100k->fck = 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 err2;
+ }
+
+ if (omap1_spi100k_reset(spi100k) < 0)
+ goto err3;
+
+ status = spi_register_master(master);
+ if (status < 0)
+ goto err3;
+
+ spi100k->state = SPI_RUNNING;
+
+ return status;
+
+err3:
+ clk_put(spi100k->fck);
+err2:
+ clk_put(spi100k->ick);
+err1:
+ spi_master_put(master);
+ return status;
+}
+
+static int __exit omap1_spi100k_remove(struct platform_device *pdev)
+{
+ struct spi_master *master;
+ struct omap1_spi100k *spi100k;
+ struct resource *r;
+ unsigned limit = 500;
+ unsigned long flags;
+ int status = 0;
+
+ master = dev_get_drvdata(&pdev->dev);
+ spi100k = spi_master_get_devdata(master);
+
+ spin_lock_irqsave(&spi100k->lock, flags);
+
+ spi100k->state = SPI_SHUTDOWN;
+ while (!list_empty(&spi100k->msg_queue) && limit--) {
+ spin_unlock_irqrestore(&spi100k->lock, flags);
+ msleep(10);
+ spin_lock_irqsave(&spi100k->lock, flags);
+ }
+
+ if (!list_empty(&spi100k->msg_queue))
+ status = -EBUSY;
+
+ spin_unlock_irqrestore(&spi100k->lock, flags);
+
+ if (status != 0)
+ return status;
+
+ clk_put(spi100k->fck);
+ clk_put(spi100k->ick);
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+ spi_unregister_master(master);
+
+ return 0;
+}
+
+static struct platform_driver omap1_spi100k_driver = {
+ .driver = {
+ .name = "omap1_spi100k",
+ .owner = THIS_MODULE,
+ },
+ .remove = __exit_p(omap1_spi100k_remove),
+};
+
+
+static int __init omap1_spi100k_init(void)
+{
+ omap1_spi100k_wq = create_singlethread_workqueue(
+ omap1_spi100k_driver.driver.name);
+
+ if (omap1_spi100k_wq == NULL)
+ return -1;
+
+ return platform_driver_probe(&omap1_spi100k_driver, omap1_spi100k_probe);
+}
+
+static void __exit omap1_spi100k_exit(void)
+{
+ platform_driver_unregister(&omap1_spi100k_driver);
+
+ destroy_workqueue(omap1_spi100k_wq);
+}
+
+module_init(omap1_spi100k_init);
+module_exit(omap1_spi100k_exit);
+
+MODULE_DESCRIPTION("OMAP7xx SPI 100k controller driver");
+MODULE_AUTHOR("Fabrice Crohas <fcrohas@gmail.com>");
+MODULE_LICENSE("GPL");
+
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-02 11:18:39 +0000