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path: root/drivers/spi/spi_tegra.c
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-rw-r--r--drivers/spi/spi_tegra.c618
1 files changed, 618 insertions, 0 deletions
diff --git a/drivers/spi/spi_tegra.c b/drivers/spi/spi_tegra.c
new file mode 100644
index 00000000000..bb7df02a547
--- /dev/null
+++ b/drivers/spi/spi_tegra.c
@@ -0,0 +1,618 @@
+/*
+ * Driver for Nvidia TEGRA spi controller.
+ *
+ * Copyright (C) 2010 Google, Inc.
+ *
+ * Author:
+ * Erik Gilling <konkers@android.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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/err.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+
+#include <linux/spi/spi.h>
+
+#include <mach/dma.h>
+
+#define SLINK_COMMAND 0x000
+#define SLINK_BIT_LENGTH(x) (((x) & 0x1f) << 0)
+#define SLINK_WORD_SIZE(x) (((x) & 0x1f) << 5)
+#define SLINK_BOTH_EN (1 << 10)
+#define SLINK_CS_SW (1 << 11)
+#define SLINK_CS_VALUE (1 << 12)
+#define SLINK_CS_POLARITY (1 << 13)
+#define SLINK_IDLE_SDA_DRIVE_LOW (0 << 16)
+#define SLINK_IDLE_SDA_DRIVE_HIGH (1 << 16)
+#define SLINK_IDLE_SDA_PULL_LOW (2 << 16)
+#define SLINK_IDLE_SDA_PULL_HIGH (3 << 16)
+#define SLINK_IDLE_SDA_MASK (3 << 16)
+#define SLINK_CS_POLARITY1 (1 << 20)
+#define SLINK_CK_SDA (1 << 21)
+#define SLINK_CS_POLARITY2 (1 << 22)
+#define SLINK_CS_POLARITY3 (1 << 23)
+#define SLINK_IDLE_SCLK_DRIVE_LOW (0 << 24)
+#define SLINK_IDLE_SCLK_DRIVE_HIGH (1 << 24)
+#define SLINK_IDLE_SCLK_PULL_LOW (2 << 24)
+#define SLINK_IDLE_SCLK_PULL_HIGH (3 << 24)
+#define SLINK_IDLE_SCLK_MASK (3 << 24)
+#define SLINK_M_S (1 << 28)
+#define SLINK_WAIT (1 << 29)
+#define SLINK_GO (1 << 30)
+#define SLINK_ENB (1 << 31)
+
+#define SLINK_COMMAND2 0x004
+#define SLINK_LSBFE (1 << 0)
+#define SLINK_SSOE (1 << 1)
+#define SLINK_SPIE (1 << 4)
+#define SLINK_BIDIROE (1 << 6)
+#define SLINK_MODFEN (1 << 7)
+#define SLINK_INT_SIZE(x) (((x) & 0x1f) << 8)
+#define SLINK_CS_ACTIVE_BETWEEN (1 << 17)
+#define SLINK_SS_EN_CS(x) (((x) & 0x3) << 18)
+#define SLINK_SS_SETUP(x) (((x) & 0x3) << 20)
+#define SLINK_FIFO_REFILLS_0 (0 << 22)
+#define SLINK_FIFO_REFILLS_1 (1 << 22)
+#define SLINK_FIFO_REFILLS_2 (2 << 22)
+#define SLINK_FIFO_REFILLS_3 (3 << 22)
+#define SLINK_FIFO_REFILLS_MASK (3 << 22)
+#define SLINK_WAIT_PACK_INT(x) (((x) & 0x7) << 26)
+#define SLINK_SPC0 (1 << 29)
+#define SLINK_TXEN (1 << 30)
+#define SLINK_RXEN (1 << 31)
+
+#define SLINK_STATUS 0x008
+#define SLINK_COUNT(val) (((val) >> 0) & 0x1f)
+#define SLINK_WORD(val) (((val) >> 5) & 0x1f)
+#define SLINK_BLK_CNT(val) (((val) >> 0) & 0xffff)
+#define SLINK_MODF (1 << 16)
+#define SLINK_RX_UNF (1 << 18)
+#define SLINK_TX_OVF (1 << 19)
+#define SLINK_TX_FULL (1 << 20)
+#define SLINK_TX_EMPTY (1 << 21)
+#define SLINK_RX_FULL (1 << 22)
+#define SLINK_RX_EMPTY (1 << 23)
+#define SLINK_TX_UNF (1 << 24)
+#define SLINK_RX_OVF (1 << 25)
+#define SLINK_TX_FLUSH (1 << 26)
+#define SLINK_RX_FLUSH (1 << 27)
+#define SLINK_SCLK (1 << 28)
+#define SLINK_ERR (1 << 29)
+#define SLINK_RDY (1 << 30)
+#define SLINK_BSY (1 << 31)
+
+#define SLINK_MAS_DATA 0x010
+#define SLINK_SLAVE_DATA 0x014
+
+#define SLINK_DMA_CTL 0x018
+#define SLINK_DMA_BLOCK_SIZE(x) (((x) & 0xffff) << 0)
+#define SLINK_TX_TRIG_1 (0 << 16)
+#define SLINK_TX_TRIG_4 (1 << 16)
+#define SLINK_TX_TRIG_8 (2 << 16)
+#define SLINK_TX_TRIG_16 (3 << 16)
+#define SLINK_TX_TRIG_MASK (3 << 16)
+#define SLINK_RX_TRIG_1 (0 << 18)
+#define SLINK_RX_TRIG_4 (1 << 18)
+#define SLINK_RX_TRIG_8 (2 << 18)
+#define SLINK_RX_TRIG_16 (3 << 18)
+#define SLINK_RX_TRIG_MASK (3 << 18)
+#define SLINK_PACKED (1 << 20)
+#define SLINK_PACK_SIZE_4 (0 << 21)
+#define SLINK_PACK_SIZE_8 (1 << 21)
+#define SLINK_PACK_SIZE_16 (2 << 21)
+#define SLINK_PACK_SIZE_32 (3 << 21)
+#define SLINK_PACK_SIZE_MASK (3 << 21)
+#define SLINK_IE_TXC (1 << 26)
+#define SLINK_IE_RXC (1 << 27)
+#define SLINK_DMA_EN (1 << 31)
+
+#define SLINK_STATUS2 0x01c
+#define SLINK_TX_FIFO_EMPTY_COUNT(val) (((val) & 0x3f) >> 0)
+#define SLINK_RX_FIFO_FULL_COUNT(val) (((val) & 0x3f) >> 16)
+
+#define SLINK_TX_FIFO 0x100
+#define SLINK_RX_FIFO 0x180
+
+static const unsigned long spi_tegra_req_sels[] = {
+ TEGRA_DMA_REQ_SEL_SL2B1,
+ TEGRA_DMA_REQ_SEL_SL2B2,
+ TEGRA_DMA_REQ_SEL_SL2B3,
+ TEGRA_DMA_REQ_SEL_SL2B4,
+};
+
+#define BB_LEN 32
+
+struct spi_tegra_data {
+ struct spi_master *master;
+ struct platform_device *pdev;
+ spinlock_t lock;
+
+ struct clk *clk;
+ void __iomem *base;
+ unsigned long phys;
+
+ u32 cur_speed;
+
+ struct list_head queue;
+ struct spi_transfer *cur;
+ unsigned cur_pos;
+ unsigned cur_len;
+ unsigned cur_bytes_per_word;
+
+ /* The tegra spi controller has a bug which causes the first word
+ * in PIO transactions to be garbage. Since packed DMA transactions
+ * require transfers to be 4 byte aligned we need a bounce buffer
+ * for the generic case.
+ */
+ struct tegra_dma_req rx_dma_req;
+ struct tegra_dma_channel *rx_dma;
+ u32 *rx_bb;
+ dma_addr_t rx_bb_phys;
+};
+
+
+static inline unsigned long spi_tegra_readl(struct spi_tegra_data *tspi,
+ unsigned long reg)
+{
+ return readl(tspi->base + reg);
+}
+
+static inline void spi_tegra_writel(struct spi_tegra_data *tspi,
+ unsigned long val,
+ unsigned long reg)
+{
+ writel(val, tspi->base + reg);
+}
+
+static void spi_tegra_go(struct spi_tegra_data *tspi)
+{
+ unsigned long val;
+
+ wmb();
+
+ val = spi_tegra_readl(tspi, SLINK_DMA_CTL);
+ val &= ~SLINK_DMA_BLOCK_SIZE(~0) & ~SLINK_DMA_EN;
+ val |= SLINK_DMA_BLOCK_SIZE(tspi->rx_dma_req.size / 4 - 1);
+ spi_tegra_writel(tspi, val, SLINK_DMA_CTL);
+
+ tegra_dma_enqueue_req(tspi->rx_dma, &tspi->rx_dma_req);
+
+ val |= SLINK_DMA_EN;
+ spi_tegra_writel(tspi, val, SLINK_DMA_CTL);
+}
+
+static unsigned spi_tegra_fill_tx_fifo(struct spi_tegra_data *tspi,
+ struct spi_transfer *t)
+{
+ unsigned len = min(t->len - tspi->cur_pos, BB_LEN *
+ tspi->cur_bytes_per_word);
+ u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_pos;
+ int i, j;
+ unsigned long val;
+
+ val = spi_tegra_readl(tspi, SLINK_COMMAND);
+ val &= ~SLINK_WORD_SIZE(~0);
+ val |= SLINK_WORD_SIZE(len / tspi->cur_bytes_per_word - 1);
+ spi_tegra_writel(tspi, val, SLINK_COMMAND);
+
+ for (i = 0; i < len; i += tspi->cur_bytes_per_word) {
+ val = 0;
+ for (j = 0; j < tspi->cur_bytes_per_word; j++)
+ val |= tx_buf[i + j] << j * 8;
+
+ spi_tegra_writel(tspi, val, SLINK_TX_FIFO);
+ }
+
+ tspi->rx_dma_req.size = len / tspi->cur_bytes_per_word * 4;
+
+ return len;
+}
+
+static unsigned spi_tegra_drain_rx_fifo(struct spi_tegra_data *tspi,
+ struct spi_transfer *t)
+{
+ unsigned len = tspi->cur_len;
+ u8 *rx_buf = (u8 *)t->rx_buf + tspi->cur_pos;
+ int i, j;
+ unsigned long val;
+
+ for (i = 0; i < len; i += tspi->cur_bytes_per_word) {
+ val = tspi->rx_bb[i / tspi->cur_bytes_per_word];
+ for (j = 0; j < tspi->cur_bytes_per_word; j++)
+ rx_buf[i + j] = (val >> (j * 8)) & 0xff;
+ }
+
+ return len;
+}
+
+static void spi_tegra_start_transfer(struct spi_device *spi,
+ struct spi_transfer *t)
+{
+ struct spi_tegra_data *tspi = spi_master_get_devdata(spi->master);
+ u32 speed;
+ u8 bits_per_word;
+ unsigned long val;
+
+ speed = t->speed_hz ? t->speed_hz : spi->max_speed_hz;
+ bits_per_word = t->bits_per_word ? t->bits_per_word :
+ spi->bits_per_word;
+
+ tspi->cur_bytes_per_word = (bits_per_word - 1) / 8 + 1;
+
+ if (speed != tspi->cur_speed)
+ clk_set_rate(tspi->clk, speed);
+
+ if (tspi->cur_speed == 0)
+ clk_enable(tspi->clk);
+
+ tspi->cur_speed = speed;
+
+ val = spi_tegra_readl(tspi, SLINK_COMMAND2);
+ val &= ~SLINK_SS_EN_CS(~0) | SLINK_RXEN | SLINK_TXEN;
+ if (t->rx_buf)
+ val |= SLINK_RXEN;
+ if (t->tx_buf)
+ val |= SLINK_TXEN;
+ val |= SLINK_SS_EN_CS(spi->chip_select);
+ val |= SLINK_SPIE;
+ spi_tegra_writel(tspi, val, SLINK_COMMAND2);
+
+ val = spi_tegra_readl(tspi, SLINK_COMMAND);
+ val &= ~SLINK_BIT_LENGTH(~0);
+ val |= SLINK_BIT_LENGTH(bits_per_word - 1);
+
+ /* FIXME: should probably control CS manually so that we can be sure
+ * it does not go low between transfer and to support delay_usecs
+ * correctly.
+ */
+ val &= ~SLINK_IDLE_SCLK_MASK & ~SLINK_CK_SDA & ~SLINK_CS_SW;
+
+ if (spi->mode & SPI_CPHA)
+ val |= SLINK_CK_SDA;
+
+ if (spi->mode & SPI_CPOL)
+ val |= SLINK_IDLE_SCLK_DRIVE_HIGH;
+ else
+ val |= SLINK_IDLE_SCLK_DRIVE_LOW;
+
+ val |= SLINK_M_S;
+
+ spi_tegra_writel(tspi, val, SLINK_COMMAND);
+
+ spi_tegra_writel(tspi, SLINK_RX_FLUSH | SLINK_TX_FLUSH, SLINK_STATUS);
+
+ tspi->cur = t;
+ tspi->cur_pos = 0;
+ tspi->cur_len = spi_tegra_fill_tx_fifo(tspi, t);
+
+ spi_tegra_go(tspi);
+}
+
+static void spi_tegra_start_message(struct spi_device *spi,
+ struct spi_message *m)
+{
+ struct spi_transfer *t;
+
+ m->actual_length = 0;
+ m->status = 0;
+
+ t = list_first_entry(&m->transfers, struct spi_transfer, transfer_list);
+ spi_tegra_start_transfer(spi, t);
+}
+
+static void tegra_spi_rx_dma_complete(struct tegra_dma_req *req)
+{
+ struct spi_tegra_data *tspi = req->dev;
+ unsigned long flags;
+ struct spi_message *m;
+ struct spi_device *spi;
+ int timeout = 0;
+ unsigned long val;
+
+ /* the SPI controller may come back with both the BSY and RDY bits
+ * set. In this case we need to wait for the BSY bit to clear so
+ * that we are sure the DMA is finished. 1000 reads was empirically
+ * determined to be long enough.
+ */
+ while (timeout++ < 1000) {
+ if (!(spi_tegra_readl(tspi, SLINK_STATUS) & SLINK_BSY))
+ break;
+ }
+
+ spin_lock_irqsave(&tspi->lock, flags);
+
+ val = spi_tegra_readl(tspi, SLINK_STATUS);
+ val |= SLINK_RDY;
+ spi_tegra_writel(tspi, val, SLINK_STATUS);
+
+ m = list_first_entry(&tspi->queue, struct spi_message, queue);
+
+ if (timeout >= 1000)
+ m->status = -EIO;
+
+ spi = m->state;
+
+ tspi->cur_pos += spi_tegra_drain_rx_fifo(tspi, tspi->cur);
+ m->actual_length += tspi->cur_pos;
+
+ if (tspi->cur_pos < tspi->cur->len) {
+ tspi->cur_len = spi_tegra_fill_tx_fifo(tspi, tspi->cur);
+ spi_tegra_go(tspi);
+ } else if (!list_is_last(&tspi->cur->transfer_list,
+ &m->transfers)) {
+ tspi->cur = list_first_entry(&tspi->cur->transfer_list,
+ struct spi_transfer,
+ transfer_list);
+ spi_tegra_start_transfer(spi, tspi->cur);
+ } else {
+ list_del(&m->queue);
+
+ m->complete(m->context);
+
+ if (!list_empty(&tspi->queue)) {
+ m = list_first_entry(&tspi->queue, struct spi_message,
+ queue);
+ spi = m->state;
+ spi_tegra_start_message(spi, m);
+ } else {
+ clk_disable(tspi->clk);
+ tspi->cur_speed = 0;
+ }
+ }
+
+ spin_unlock_irqrestore(&tspi->lock, flags);
+}
+
+static int spi_tegra_setup(struct spi_device *spi)
+{
+ struct spi_tegra_data *tspi = spi_master_get_devdata(spi->master);
+ unsigned long cs_bit;
+ unsigned long val;
+ unsigned long flags;
+
+ dev_dbg(&spi->dev, "setup %d bpw, %scpol, %scpha, %dHz\n",
+ spi->bits_per_word,
+ spi->mode & SPI_CPOL ? "" : "~",
+ spi->mode & SPI_CPHA ? "" : "~",
+ spi->max_speed_hz);
+
+
+ switch (spi->chip_select) {
+ case 0:
+ cs_bit = SLINK_CS_POLARITY;
+ break;
+
+ case 1:
+ cs_bit = SLINK_CS_POLARITY1;
+ break;
+
+ case 2:
+ cs_bit = SLINK_CS_POLARITY2;
+ break;
+
+ case 4:
+ cs_bit = SLINK_CS_POLARITY3;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&tspi->lock, flags);
+
+ val = spi_tegra_readl(tspi, SLINK_COMMAND);
+ if (spi->mode & SPI_CS_HIGH)
+ val |= cs_bit;
+ else
+ val &= ~cs_bit;
+ spi_tegra_writel(tspi, val, SLINK_COMMAND);
+
+ spin_unlock_irqrestore(&tspi->lock, flags);
+
+ return 0;
+}
+
+static int spi_tegra_transfer(struct spi_device *spi, struct spi_message *m)
+{
+ struct spi_tegra_data *tspi = spi_master_get_devdata(spi->master);
+ struct spi_transfer *t;
+ unsigned long flags;
+ int was_empty;
+
+ if (list_empty(&m->transfers) || !m->complete)
+ return -EINVAL;
+
+ list_for_each_entry(t, &m->transfers, transfer_list) {
+ if (t->bits_per_word < 0 || t->bits_per_word > 32)
+ return -EINVAL;
+
+ if (t->len == 0)
+ return -EINVAL;
+
+ if (!t->rx_buf && !t->tx_buf)
+ return -EINVAL;
+ }
+
+ m->state = spi;
+
+ spin_lock_irqsave(&tspi->lock, flags);
+ was_empty = list_empty(&tspi->queue);
+ list_add_tail(&m->queue, &tspi->queue);
+
+ if (was_empty)
+ spi_tegra_start_message(spi, m);
+
+ spin_unlock_irqrestore(&tspi->lock, flags);
+
+ return 0;
+}
+
+static int __init spi_tegra_probe(struct platform_device *pdev)
+{
+ struct spi_master *master;
+ struct spi_tegra_data *tspi;
+ struct resource *r;
+ int ret;
+
+ master = spi_alloc_master(&pdev->dev, sizeof *tspi);
+ if (master == NULL) {
+ dev_err(&pdev->dev, "master allocation failed\n");
+ return -ENOMEM;
+ }
+
+ /* the spi->mode bits understood by this driver: */
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+
+ master->bus_num = pdev->id;
+
+ master->setup = spi_tegra_setup;
+ master->transfer = spi_tegra_transfer;
+ master->num_chipselect = 4;
+
+ dev_set_drvdata(&pdev->dev, master);
+ tspi = spi_master_get_devdata(master);
+ tspi->master = master;
+ tspi->pdev = pdev;
+ spin_lock_init(&tspi->lock);
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (r == NULL) {
+ ret = -ENODEV;
+ goto err0;
+ }
+
+ if (!request_mem_region(r->start, (r->end - r->start) + 1,
+ dev_name(&pdev->dev))) {
+ ret = -EBUSY;
+ goto err0;
+ }
+
+ tspi->phys = r->start;
+ tspi->base = ioremap(r->start, r->end - r->start + 1);
+ if (!tspi->base) {
+ dev_err(&pdev->dev, "can't ioremap iomem\n");
+ ret = -ENOMEM;
+ goto err1;
+ }
+
+ tspi->clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR_OR_NULL(tspi->clk)) {
+ dev_err(&pdev->dev, "can not get clock\n");
+ ret = PTR_ERR(tspi->clk);
+ goto err2;
+ }
+
+ INIT_LIST_HEAD(&tspi->queue);
+
+ tspi->rx_dma = tegra_dma_allocate_channel(TEGRA_DMA_MODE_ONESHOT);
+ if (!tspi->rx_dma) {
+ dev_err(&pdev->dev, "can not allocate rx dma channel\n");
+ ret = -ENODEV;
+ goto err3;
+ }
+
+ tspi->rx_bb = dma_alloc_coherent(&pdev->dev, sizeof(u32) * BB_LEN,
+ &tspi->rx_bb_phys, GFP_KERNEL);
+ if (!tspi->rx_bb) {
+ dev_err(&pdev->dev, "can not allocate rx bounce buffer\n");
+ ret = -ENOMEM;
+ goto err4;
+ }
+
+ tspi->rx_dma_req.complete = tegra_spi_rx_dma_complete;
+ tspi->rx_dma_req.to_memory = 1;
+ tspi->rx_dma_req.dest_addr = tspi->rx_bb_phys;
+ tspi->rx_dma_req.dest_bus_width = 32;
+ tspi->rx_dma_req.source_addr = tspi->phys + SLINK_RX_FIFO;
+ tspi->rx_dma_req.source_bus_width = 32;
+ tspi->rx_dma_req.source_wrap = 4;
+ tspi->rx_dma_req.req_sel = spi_tegra_req_sels[pdev->id];
+ tspi->rx_dma_req.dev = tspi;
+
+ ret = spi_register_master(master);
+
+ if (ret < 0)
+ goto err5;
+
+ return ret;
+
+err5:
+ dma_free_coherent(&pdev->dev, sizeof(u32) * BB_LEN,
+ tspi->rx_bb, tspi->rx_bb_phys);
+err4:
+ tegra_dma_free_channel(tspi->rx_dma);
+err3:
+ clk_put(tspi->clk);
+err2:
+ iounmap(tspi->base);
+err1:
+ release_mem_region(r->start, (r->end - r->start) + 1);
+err0:
+ spi_master_put(master);
+ return ret;
+}
+
+static int __devexit spi_tegra_remove(struct platform_device *pdev)
+{
+ struct spi_master *master;
+ struct spi_tegra_data *tspi;
+ struct resource *r;
+
+ master = dev_get_drvdata(&pdev->dev);
+ tspi = spi_master_get_devdata(master);
+
+ tegra_dma_free_channel(tspi->rx_dma);
+
+ dma_free_coherent(&pdev->dev, sizeof(u32) * BB_LEN,
+ tspi->rx_bb, tspi->rx_bb_phys);
+
+ clk_put(tspi->clk);
+ iounmap(tspi->base);
+
+ spi_master_put(master);
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ release_mem_region(r->start, (r->end - r->start) + 1);
+
+ return 0;
+}
+
+MODULE_ALIAS("platform:spi_tegra");
+
+static struct platform_driver spi_tegra_driver = {
+ .driver = {
+ .name = "spi_tegra",
+ .owner = THIS_MODULE,
+ },
+ .remove = __devexit_p(spi_tegra_remove),
+};
+
+static int __init spi_tegra_init(void)
+{
+ return platform_driver_probe(&spi_tegra_driver, spi_tegra_probe);
+}
+module_init(spi_tegra_init);
+
+static void __exit spi_tegra_exit(void)
+{
+ platform_driver_unregister(&spi_tegra_driver);
+}
+module_exit(spi_tegra_exit);
+
+MODULE_LICENSE("GPL");
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-23 19:16:31 +0000