summaryrefslogtreecommitdiffstats
path: root/drivers/spi/spi-omap-100k.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--drivers/spi/spi-omap-100k.c502
1 files changed, 502 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..2eeb0fe2e
--- /dev/null
+++ b/drivers/spi/spi-omap-100k.c
@@ -0,0 +1,502 @@
+/*
+ * 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;
+
+ if (t != NULL)
+ word_len = t->bits_per_word;
+ else
+ word_len = spi->bits_per_word;
+
+ if (word_len > 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 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;
+ }
+ status = omap1_spi100k_setup_transfer(spi, t);
+ if (status < 0)
+ break;
+
+ 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;
+ }
+ }
+
+ 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 = 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 = 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 = 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");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-28 14:36:07 +0000