+/*
+ * drivers/spi/spi_imx.c
+ *
+ * Copyright (C) 2006 SWAPP
+ * Andrea Paterniani <a.paterniani@swapp-eng.it>
+ *
+ * Initial version inspired by:
+ * linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c
+ *
+ * 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/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/ioport.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/spi/spi.h>
+#include <linux/workqueue.h>
+#include <linux/delay.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/hardware.h>
+#include <asm/delay.h>
+
+#include <asm/arch/hardware.h>
+#include <asm/arch/imx-dma.h>
+#include <asm/arch/spi_imx.h>
+
+/*-------------------------------------------------------------------------*/
+/* SPI Registers offsets from peripheral base address */
+#define SPI_RXDATA (0x00)
+#define SPI_TXDATA (0x04)
+#define SPI_CONTROL (0x08)
+#define SPI_INT_STATUS (0x0C)
+#define SPI_TEST (0x10)
+#define SPI_PERIOD (0x14)
+#define SPI_DMA (0x18)
+#define SPI_RESET (0x1C)
+
+/* SPI Control Register Bit Fields & Masks */
+#define SPI_CONTROL_BITCOUNT_MASK (0xF) /* Bit Count Mask */
+#define SPI_CONTROL_BITCOUNT(n) (((n) - 1) & SPI_CONTROL_BITCOUNT_MASK)
+#define SPI_CONTROL_POL (0x1 << 4) /* Clock Polarity Mask */
+#define SPI_CONTROL_POL_ACT_HIGH (0x0 << 4) /* Active high pol. (0=idle) */
+#define SPI_CONTROL_POL_ACT_LOW (0x1 << 4) /* Active low pol. (1=idle) */
+#define SPI_CONTROL_PHA (0x1 << 5) /* Clock Phase Mask */
+#define SPI_CONTROL_PHA_0 (0x0 << 5) /* Clock Phase 0 */
+#define SPI_CONTROL_PHA_1 (0x1 << 5) /* Clock Phase 1 */
+#define SPI_CONTROL_SSCTL (0x1 << 6) /* /SS Waveform Select Mask */
+#define SPI_CONTROL_SSCTL_0 (0x0 << 6) /* Master: /SS stays low between SPI burst
+ Slave: RXFIFO advanced by BIT_COUNT */
+#define SPI_CONTROL_SSCTL_1 (0x1 << 6) /* Master: /SS insert pulse between SPI burst
+ Slave: RXFIFO advanced by /SS rising edge */
+#define SPI_CONTROL_SSPOL (0x1 << 7) /* /SS Polarity Select Mask */
+#define SPI_CONTROL_SSPOL_ACT_LOW (0x0 << 7) /* /SS Active low */
+#define SPI_CONTROL_SSPOL_ACT_HIGH (0x1 << 7) /* /SS Active high */
+#define SPI_CONTROL_XCH (0x1 << 8) /* Exchange */
+#define SPI_CONTROL_SPIEN (0x1 << 9) /* SPI Module Enable */
+#define SPI_CONTROL_MODE (0x1 << 10) /* SPI Mode Select Mask */
+#define SPI_CONTROL_MODE_SLAVE (0x0 << 10) /* SPI Mode Slave */
+#define SPI_CONTROL_MODE_MASTER (0x1 << 10) /* SPI Mode Master */
+#define SPI_CONTROL_DRCTL (0x3 << 11) /* /SPI_RDY Control Mask */
+#define SPI_CONTROL_DRCTL_0 (0x0 << 11) /* Ignore /SPI_RDY */
+#define SPI_CONTROL_DRCTL_1 (0x1 << 11) /* /SPI_RDY falling edge triggers input */
+#define SPI_CONTROL_DRCTL_2 (0x2 << 11) /* /SPI_RDY active low level triggers input */
+#define SPI_CONTROL_DATARATE (0x7 << 13) /* Data Rate Mask */
+#define SPI_PERCLK2_DIV_MIN (0) /* PERCLK2:4 */
+#define SPI_PERCLK2_DIV_MAX (7) /* PERCLK2:512 */
+#define SPI_CONTROL_DATARATE_MIN (SPI_PERCLK2_DIV_MAX << 13)
+#define SPI_CONTROL_DATARATE_MAX (SPI_PERCLK2_DIV_MIN << 13)
+#define SPI_CONTROL_DATARATE_BAD (SPI_CONTROL_DATARATE_MIN + 1)
+
+/* SPI Interrupt/Status Register Bit Fields & Masks */
+#define SPI_STATUS_TE (0x1 << 0) /* TXFIFO Empty Status */
+#define SPI_STATUS_TH (0x1 << 1) /* TXFIFO Half Status */
+#define SPI_STATUS_TF (0x1 << 2) /* TXFIFO Full Status */
+#define SPI_STATUS_RR (0x1 << 3) /* RXFIFO Data Ready Status */
+#define SPI_STATUS_RH (0x1 << 4) /* RXFIFO Half Status */
+#define SPI_STATUS_RF (0x1 << 5) /* RXFIFO Full Status */
+#define SPI_STATUS_RO (0x1 << 6) /* RXFIFO Overflow */
+#define SPI_STATUS_BO (0x1 << 7) /* Bit Count Overflow */
+#define SPI_STATUS (0xFF) /* SPI Status Mask */
+#define SPI_INTEN_TE (0x1 << 8) /* TXFIFO Empty Interrupt Enable */
+#define SPI_INTEN_TH (0x1 << 9) /* TXFIFO Half Interrupt Enable */
+#define SPI_INTEN_TF (0x1 << 10) /* TXFIFO Full Interrupt Enable */
+#define SPI_INTEN_RE (0x1 << 11) /* RXFIFO Data Ready Interrupt Enable */
+#define SPI_INTEN_RH (0x1 << 12) /* RXFIFO Half Interrupt Enable */
+#define SPI_INTEN_RF (0x1 << 13) /* RXFIFO Full Interrupt Enable */
+#define SPI_INTEN_RO (0x1 << 14) /* RXFIFO Overflow Interrupt Enable */
+#define SPI_INTEN_BO (0x1 << 15) /* Bit Count Overflow Interrupt Enable */
+#define SPI_INTEN (0xFF << 8) /* SPI Interrupt Enable Mask */
+
+/* SPI Test Register Bit Fields & Masks */
+#define SPI_TEST_TXCNT (0xF << 0) /* TXFIFO Counter */
+#define SPI_TEST_RXCNT_LSB (4) /* RXFIFO Counter LSB */
+#define SPI_TEST_RXCNT (0xF << 4) /* RXFIFO Counter */
+#define SPI_TEST_SSTATUS (0xF << 8) /* State Machine Status */
+#define SPI_TEST_LBC (0x1 << 14) /* Loop Back Control */
+
+/* SPI Period Register Bit Fields & Masks */
+#define SPI_PERIOD_WAIT (0x7FFF << 0) /* Wait Between Transactions */
+#define SPI_PERIOD_MAX_WAIT (0x7FFF) /* Max Wait Between
+ Transactions */
+#define SPI_PERIOD_CSRC (0x1 << 15) /* Period Clock Source Mask */
+#define SPI_PERIOD_CSRC_BCLK (0x0 << 15) /* Period Clock Source is
+ Bit Clock */
+#define SPI_PERIOD_CSRC_32768 (0x1 << 15) /* Period Clock Source is
+ 32.768 KHz Clock */
+
+/* SPI DMA Register Bit Fields & Masks */
+#define SPI_DMA_RHDMA (0xF << 4) /* RXFIFO Half Status */
+#define SPI_DMA_RFDMA (0x1 << 5) /* RXFIFO Full Status */
+#define SPI_DMA_TEDMA (0x1 << 6) /* TXFIFO Empty Status */
+#define SPI_DMA_THDMA (0x1 << 7) /* TXFIFO Half Status */
+#define SPI_DMA_RHDEN (0x1 << 12) /* RXFIFO Half DMA Request Enable */
+#define SPI_DMA_RFDEN (0x1 << 13) /* RXFIFO Full DMA Request Enable */
+#define SPI_DMA_TEDEN (0x1 << 14) /* TXFIFO Empty DMA Request Enable */
+#define SPI_DMA_THDEN (0x1 << 15) /* TXFIFO Half DMA Request Enable */
+
+/* SPI Soft Reset Register Bit Fields & Masks */
+#define SPI_RESET_START (0x1) /* Start */
+
+/* Default SPI configuration values */
+#define SPI_DEFAULT_CONTROL \
+( \
+ SPI_CONTROL_BITCOUNT(16) | \
+ SPI_CONTROL_POL_ACT_HIGH | \
+ SPI_CONTROL_PHA_0 | \
+ SPI_CONTROL_SPIEN | \
+ SPI_CONTROL_SSCTL_1 | \
+ SPI_CONTROL_MODE_MASTER | \
+ SPI_CONTROL_DRCTL_0 | \
+ SPI_CONTROL_DATARATE_MIN \
+)
+#define SPI_DEFAULT_ENABLE_LOOPBACK (0)
+#define SPI_DEFAULT_ENABLE_DMA (0)
+#define SPI_DEFAULT_PERIOD_WAIT (8)
+/*-------------------------------------------------------------------------*/
+
+
+/*-------------------------------------------------------------------------*/
+/* TX/RX SPI FIFO size */
+#define SPI_FIFO_DEPTH (8)
+#define SPI_FIFO_BYTE_WIDTH (2)
+#define SPI_FIFO_OVERFLOW_MARGIN (2)
+
+/* DMA burst lenght for half full/empty request trigger */
+#define SPI_DMA_BLR (SPI_FIFO_DEPTH * SPI_FIFO_BYTE_WIDTH / 2)
+
+/* Dummy char output to achieve reads.
+ Choosing something different from all zeroes may help pattern recogition
+ for oscilloscope analysis, but may break some drivers. */
+#define SPI_DUMMY_u8 0
+#define SPI_DUMMY_u16 ((SPI_DUMMY_u8 << 8) | SPI_DUMMY_u8)
+#define SPI_DUMMY_u32 ((SPI_DUMMY_u16 << 16) | SPI_DUMMY_u16)
+
+/**
+ * Macro to change a u32 field:
+ * @r : register to edit
+ * @m : bit mask
+ * @v : new value for the field correctly bit-alligned
+*/
+#define u32_EDIT(r, m, v) r = (r & ~(m)) | (v)
+
+/* Message state */
+#define START_STATE ((void*)0)
+#define RUNNING_STATE ((void*)1)
+#define DONE_STATE ((void*)2)
+#define ERROR_STATE ((void*)-1)
+
+/* Queue state */
+#define QUEUE_RUNNING (0)
+#define QUEUE_STOPPED (1)
+
+#define IS_DMA_ALIGNED(x) (((u32)(x) & 0x03) == 0)
+/*-------------------------------------------------------------------------*/
+
+
+/*-------------------------------------------------------------------------*/
+/* Driver data structs */
+
+/* Context */
+struct driver_data {
+ /* Driver model hookup */
+ struct platform_device *pdev;
+
+ /* SPI framework hookup */
+ struct spi_master *master;
+
+ /* IMX hookup */
+ struct spi_imx_master *master_info;
+
+ /* Memory resources and SPI regs virtual address */
+ struct resource *ioarea;
+ void __iomem *regs;
+
+ /* SPI RX_DATA physical address */
+ dma_addr_t rd_data_phys;
+
+ /* Driver message queue */
+ struct workqueue_struct *workqueue;
+ struct work_struct work;
+ spinlock_t lock;
+ struct list_head queue;
+ int busy;
+ int run;
+
+ /* Message Transfer pump */
+ struct tasklet_struct pump_transfers;
+
+ /* Current message, transfer and state */
+ struct spi_message *cur_msg;
+ struct spi_transfer *cur_transfer;
+ struct chip_data *cur_chip;
+
+ /* Rd / Wr buffers pointers */
+ size_t len;
+ void *tx;
+ void *tx_end;
+ void *rx;
+ void *rx_end;
+
+ u8 rd_only;
+ u8 n_bytes;
+ int cs_change;
+
+ /* Function pointers */
+ irqreturn_t (*transfer_handler)(struct driver_data *drv_data);
+ void (*cs_control)(u32 command);
+
+ /* DMA setup */
+ int rx_channel;
+ int tx_channel;
+ dma_addr_t rx_dma;
+ dma_addr_t tx_dma;
+ int rx_dma_needs_unmap;
+ int tx_dma_needs_unmap;
+ size_t tx_map_len;
+ u32 dummy_dma_buf ____cacheline_aligned;
+};
+
+/* Runtime state */
+struct chip_data {
+ u32 control;
+ u32 period;
+ u32 test;
+
+ u8 enable_dma:1;
+ u8 bits_per_word;
+ u8 n_bytes;
+ u32 max_speed_hz;
+
+ void (*cs_control)(u32 command);
+};
+/*-------------------------------------------------------------------------*/
+
+
+static void pump_messages(struct work_struct *work);
+
+static int flush(struct driver_data *drv_data)
+{
+ unsigned long limit = loops_per_jiffy << 1;
+ void __iomem *regs = drv_data->regs;
+ volatile u32 d;
+
+ dev_dbg(&drv_data->pdev->dev, "flush\n");
+ do {
+ while (readl(regs + SPI_INT_STATUS) & SPI_STATUS_RR)
+ d = readl(regs + SPI_RXDATA);
+ } while ((readl(regs + SPI_CONTROL) & SPI_CONTROL_XCH) && limit--);
+
+ return limit;
+}
+
+static void restore_state(struct driver_data *drv_data)
+{
+ void __iomem *regs = drv_data->regs;
+ struct chip_data *chip = drv_data->cur_chip;
+
+ /* Load chip registers */
+ dev_dbg(&drv_data->pdev->dev,
+ "restore_state\n"
+ " test = 0x%08X\n"
+ " control = 0x%08X\n",
+ chip->test,
+ chip->control);
+ writel(chip->test, regs + SPI_TEST);
+ writel(chip->period, regs + SPI_PERIOD);
+ writel(0, regs + SPI_INT_STATUS);
+ writel(chip->control, regs + SPI_CONTROL);
+}
+
+static void null_cs_control(u32 command)
+{
+}
+
+static inline u32 data_to_write(struct driver_data *drv_data)
+{
+ return ((u32)(drv_data->tx_end - drv_data->tx)) / drv_data->n_bytes;
+}
+
+static inline u32 data_to_read(struct driver_data *drv_data)
+{
+ return ((u32)(drv_data->rx_end - drv_data->rx)) / drv_data->n_bytes;
+}
+
+static int write(struct driver_data *drv_data)
+{
+ void __iomem *regs = drv_data->regs;
+ void *tx = drv_data->tx;
+ void *tx_end = drv_data->tx_end;
+ u8 n_bytes = drv_data->n_bytes;
+ u32 remaining_writes;
+ u32 fifo_avail_space;
+ u32 n;
+ u16 d;
+
+ /* Compute how many fifo writes to do */
+ remaining_writes = (u32)(tx_end - tx) / n_bytes;
+ fifo_avail_space = SPI_FIFO_DEPTH -
+ (readl(regs + SPI_TEST) & SPI_TEST_TXCNT);
+ if (drv_data->rx && (fifo_avail_space > SPI_FIFO_OVERFLOW_MARGIN))
+ /* Fix misunderstood receive overflow */
+ fifo_avail_space -= SPI_FIFO_OVERFLOW_MARGIN;
+ n = min(remaining_writes, fifo_avail_space);
+
+ dev_dbg(&drv_data->pdev->dev,
+ "write type %s\n"
+ " remaining writes = %d\n"
+ " fifo avail space = %d\n"
+ " fifo writes = %d\n",
+ (n_bytes == 1) ? "u8" : "u16",
+ remaining_writes,
+ fifo_avail_space,
+ n);
+
+ if (n > 0) {
+ /* Fill SPI TXFIFO */
+ if (drv_data->rd_only) {
+ tx += n * n_bytes;
+ while (n--)
+ writel(SPI_DUMMY_u16, regs + SPI_TXDATA);
+ } else {
+ if (n_bytes == 1) {
+ while (n--) {
+ d = *(u8*)tx;
+ writel(d, regs + SPI_TXDATA);
+ tx += 1;
+ }
+ } else {
+ while (n--) {
+ d = *(u16*)tx;
+ writel(d, regs + SPI_TXDATA);
+ tx += 2;
+ }
+ }
+ }
+
+ /* Trigger transfer */
+ writel(readl(regs + SPI_CONTROL) | SPI_CONTROL_XCH,
+ regs + SPI_CONTROL);
+
+ /* Update tx pointer */
+ drv_data->tx = tx;
+ }
+
+ return (tx >= tx_end);
+}
+
+static int read(struct driver_data *drv_data)
+{
+ void __iomem *regs = drv_data->regs;
+ void *rx = drv_data->rx;
+ void *rx_end = drv_data->rx_end;
+ u8 n_bytes = drv_data->n_bytes;
+ u32 remaining_reads;
+ u32 fifo_rxcnt;
+ u32 n;
+ u16 d;
+
+ /* Compute how many fifo reads to do */
+ remaining_reads = (u32)(rx_end - rx) / n_bytes;
+ fifo_rxcnt = (readl(regs + SPI_TEST) & SPI_TEST_RXCNT) >>
+ SPI_TEST_RXCNT_LSB;
+ n = min(remaining_reads, fifo_rxcnt);
+
+ dev_dbg(&drv_data->pdev->dev,
+ "read type %s\n"
+ " remaining reads = %d\n"
+ " fifo rx count = %d\n"
+ " fifo reads = %d\n",
+ (n_bytes == 1) ? "u8" : "u16",
+ remaining_reads,
+ fifo_rxcnt,
+ n);
+
+ if (n > 0) {
+ /* Read SPI RXFIFO */
+ if (n_bytes == 1) {
+ while (n--) {
+ d = readl(regs + SPI_RXDATA);
+ *((u8*)rx) = d;
+ rx += 1;
+ }
+ } else {
+ while (n--) {
+ d = readl(regs + SPI_RXDATA);
+ *((u16*)rx) = d;
+ rx += 2;
+ }
+ }
+
+ /* Update rx pointer */
+ drv_data->rx = rx;
+ }
+
+ return (rx >= rx_end);
+}
+
+static void *next_transfer(struct driver_data *drv_data)
+{
+ struct spi_message *msg = drv_data->cur_msg;
+ struct spi_transfer *trans = drv_data->cur_transfer;
+
+ /* Move to next transfer */
+ if (trans->transfer_list.next != &msg->transfers) {
+ drv_data->cur_transfer =
+ list_entry(trans->transfer_list.next,
+ struct spi_transfer,
+ transfer_list);
+ return RUNNING_STATE;
+ }
+
+ return DONE_STATE;
+}
+
+static int map_dma_buffers(struct driver_data *drv_data)
+{
+ struct spi_message *msg;
+ struct device *dev;
+ void *buf;
+
+ drv_data->rx_dma_needs_unmap = 0;
+ drv_data->tx_dma_needs_unmap = 0;
+
+ if (!drv_data->master_info->enable_dma ||
+ !drv_data->cur_chip->enable_dma)
+ return -1;
+
+ msg = drv_data->cur_msg;
+ dev = &msg->spi->dev;
+ if (msg->is_dma_mapped) {
+ if (drv_data->tx_dma)
+ /* The caller provided at least dma and cpu virtual
+ address for write; pump_transfers() will consider the
+ transfer as write only if cpu rx virtual address is
+ NULL */
+ return 0;
+
+ if (drv_data->rx_dma) {
+ /* The caller provided dma and cpu virtual address to
+ performe read only transfer -->
+ use drv_data->dummy_dma_buf for dummy writes to
+ achive reads */
+ buf = &drv_data->dummy_dma_buf;
+ drv_data->tx_map_len = sizeof(drv_data->dummy_dma_buf);
+ drv_data->tx_dma = dma_map_single(dev,
+ buf,
+ drv_data->tx_map_len,
+ DMA_TO_DEVICE);
+ if (dma_mapping_error(drv_data->tx_dma))
+ return -1;
+
+ drv_data->tx_dma_needs_unmap = 1;
+
+ /* Flags transfer as rd_only for pump_transfers() DMA
+ regs programming (should be redundant) */
+ drv_data->tx = NULL;
+
+ return 0;
+ }
+ }
+
+ if (!IS_DMA_ALIGNED(drv_data->rx) || !IS_DMA_ALIGNED(drv_data->tx))
+ return -1;
+
+ /* NULL rx means write-only transfer and no map needed
+ since rx DMA will not be used */
+ if (drv_data->rx) {
+ buf = drv_data->rx;
+ drv_data->rx_dma = dma_map_single(
+ dev,
+ buf,
+ drv_data->len,
+ DMA_FROM_DEVICE);
+ if (dma_mapping_error(drv_data->rx_dma))
+ return -1;
+ drv_data->rx_dma_needs_unmap = 1;
+ }
+
+ if (drv_data->tx == NULL) {
+ /* Read only message --> use drv_data->dummy_dma_buf for dummy
+ writes to achive reads */
+ buf = &drv_data->dummy_dma_buf;
+ drv_data->tx_map_len = sizeof(drv_data->dummy_dma_buf);
+ } else {
+ buf = drv_data->tx;
+ drv_data->tx_map_len = drv_data->len;
+ }
+ drv_data->tx_dma = dma_map_single(dev,
+ buf,
+ drv_data->tx_map_len,
+ DMA_TO_DEVICE);
+ if (dma_mapping_error(drv_data->tx_dma)) {
+ if (drv_data->rx_dma) {
+ dma_unmap_single(dev,
+ drv_data->rx_dma,
+ drv_data->len,
+ DMA_FROM_DEVICE);
+ drv_data->rx_dma_needs_unmap = 0;
+ }
+ return -1;
+ }
+ drv_data->tx_dma_needs_unmap = 1;
+
+ return 0;
+}
+
+static void unmap_dma_buffers(struct driver_data *drv_data)
+{
+ struct spi_message *msg = drv_data->cur_msg;
+ struct device *dev = &msg->spi->dev;
+
+ if (drv_data->rx_dma_needs_unmap) {
+ dma_unmap_single(dev,
+ drv_data->rx_dma,
+ drv_data->len,
+ DMA_FROM_DEVICE);
+ drv_data->rx_dma_needs_unmap = 0;
+ }
+ if (drv_data->tx_dma_needs_unmap) {
+ dma_unmap_single(dev,
+ drv_data->tx_dma,
+ drv_data->tx_map_len,
+ DMA_TO_DEVICE);
+ drv_data->tx_dma_needs_unmap = 0;
+ }
+}
+
+/* Caller already set message->status (dma is already blocked) */
+static void giveback(struct spi_message *message, struct driver_data *drv_data)
+{
+ void __iomem *regs = drv_data->regs;
+
+ /* Bring SPI to sleep; restore_state() and pump_transfer()
+ will do new setup */
+ writel(0, regs + SPI_INT_STATUS);
+ writel(0, regs + SPI_DMA);
+
+ drv_data->cs_control(SPI_CS_DEASSERT);
+
+ message->state = NULL;
+ if (message->complete)
+ message->complete(message->context);
+
+ drv_data->cur_msg = NULL;
+ drv_data->cur_transfer = NULL;
+ drv_data->cur_chip = NULL;
+ queue_work(drv_data->workqueue, &drv_data->work);
+}
+
+static void dma_err_handler(int channel, void *data, int errcode)
+{
+ struct driver_data *drv_data = data;
+ struct spi_message *msg = drv_data->cur_msg;
+
+ dev_dbg(&drv_data->pdev->dev, "dma_err_handler\n");
+
+ /* Disable both rx and tx dma channels */
+ imx_dma_disable(drv_data->rx_channel);
+ imx_dma_disable(drv_data->tx_channel);
+
+ if (flush(drv_data) == 0)
+ dev_err(&drv_data->pdev->dev,
+ "dma_err_handler - flush failed\n");
+
+ unmap_dma_buffers(drv_data);
+
+ msg->state = ERROR_STATE;
+ tasklet_schedule(&drv_data->pump_transfers);
+}
+
+static void dma_tx_handler(int channel, void *data)
+{
+ struct driver_data *drv_data = data;
+
+ dev_dbg(&drv_data->pdev->dev, "dma_tx_handler\n");
+
+ imx_dma_disable(channel);
+
+ /* Now waits for TX FIFO empty */
+ writel(readl(drv_data->regs + SPI_INT_STATUS) | SPI_INTEN_TE,
+ drv_data->regs + SPI_INT_STATUS);
+}
+
+static irqreturn_t dma_transfer(struct driver_data *drv_data)
+{
+ u32 status;
+ struct spi_message *msg = drv_data->cur_msg;
+ void __iomem *regs = drv_data->regs;
+ unsigned long limit;
+
+ status = readl(regs + SPI_INT_STATUS);
+
+ if ((status & SPI_INTEN_RO) && (status & SPI_STATUS_RO)) {
+ writel(status & ~SPI_INTEN, regs + SPI_INT_STATUS);
+
+ imx_dma_disable(drv_data->rx_channel);
+ unmap_dma_buffers(drv_data);
+
+ if (flush(drv_data) == 0)
+ dev_err(&drv_data->pdev->dev,
+ "dma_transfer - flush failed\n");
+
+ dev_warn(&drv_data->pdev->dev,
+ "dma_transfer - fifo overun\n");
+
+ msg->state = ERROR_STATE;
+ tasklet_schedule(&drv_data->pump_transfers);
+
+ return IRQ_HANDLED;
+ }
+
+ if (status & SPI_STATUS_TE) {
+ writel(status & ~SPI_INTEN_TE, regs + SPI_INT_STATUS);
+
+ if (drv_data->rx) {
+ /* Wait end of transfer before read trailing data */
+ limit = loops_per_jiffy << 1;
+ while ((readl(regs + SPI_CONTROL) & SPI_CONTROL_XCH) &&
+ limit--);
+
+ if (limit == 0)
+ dev_err(&drv_data->pdev->dev,
+ "dma_transfer - end of tx failed\n");
+ else
+ dev_dbg(&drv_data->pdev->dev,
+ "dma_transfer - end of tx\n");
+
+ imx_dma_disable(drv_data->rx_channel);
+ unmap_dma_buffers(drv_data);
+
+ /* Calculate number of trailing data and read them */
+ dev_dbg(&drv_data->pdev->dev,
+ "dma_transfer - test = 0x%08X\n",
+ readl(regs + SPI_TEST));
+ drv_data->rx = drv_data->rx_end -
+ ((readl(regs + SPI_TEST) &
+ SPI_TEST_RXCNT) >>
+ SPI_TEST_RXCNT_LSB)*drv_data->n_bytes;
+ read(drv_data);
+ } else {
+ /* Write only transfer */
+ unmap_dma_buffers(drv_data);
+
+ if (flush(drv_data) == 0)
+ dev_err(&drv_data->pdev->dev,
+ "dma_transfer - flush failed\n");
+ }
+
+ /* End of transfer, update total byte transfered */
+ msg->actual_length += drv_data->len;
+
+ /* Release chip select if requested, transfer delays are
+ handled in pump_transfers() */
+ if (drv_data->cs_change)
+ drv_data->cs_control(SPI_CS_DEASSERT);
+
+ /* Move to next transfer */
+ msg->state = next_transfer(drv_data);
+
+ /* Schedule transfer tasklet */
+ tasklet_schedule(&drv_data->pump_transfers);
+
+ return IRQ_HANDLED;
+ }
+
+ /* Opps problem detected */
+ return IRQ_NONE;
+}
+
+static irqreturn_t interrupt_wronly_transfer(struct driver_data *drv_data)
+{
+ struct spi_message *msg = drv_data->cur_msg;
+ void __iomem *regs = drv_data->regs;
+ u32 status;
+ irqreturn_t handled = IRQ_NONE;
+
+ status = readl(regs + SPI_INT_STATUS);
+
+ while (status & SPI_STATUS_TH) {
+ dev_dbg(&drv_data->pdev->dev,
+ "interrupt_wronly_transfer - status = 0x%08X\n", status);
+
+ /* Pump data */
+ if (write(drv_data)) {
+ writel(readl(regs + SPI_INT_STATUS) & ~SPI_INTEN,
+ regs + SPI_INT_STATUS);
+
+ dev_dbg(&drv_data->pdev->dev,
+ "interrupt_wronly_transfer - end of tx\n");
+
+ if (flush(drv_data) == 0)
+ dev_err(&drv_data->pdev->dev,
+ "interrupt_wronly_transfer - "
+ "flush failed\n");
+
+ /* End of transfer, update total byte transfered */
+ msg->actual_length += drv_data->len;
+
+ /* Release chip select if requested, transfer delays are
+ handled in pump_transfers */
+ if (drv_data->cs_change)
+ drv_data->cs_control(SPI_CS_DEASSERT);
+
+ /* Move to next transfer */
+ msg->state = next_transfer(drv_data);
+
+ /* Schedule transfer tasklet */
+ tasklet_schedule(&drv_data->pump_transfers);
+
+ return IRQ_HANDLED;
+ }
+
+ status = readl(regs + SPI_INT_STATUS);
+
+ /* We did something */
+ handled = IRQ_HANDLED;
+ }
+
+ return handled;
+}
+
+static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
+{
+ struct spi_message *msg = drv_data->cur_msg;
+ void __iomem *regs = drv_data->regs;
+ u32 status;
+ irqreturn_t handled = IRQ_NONE;
+ unsigned long limit;
+
+ status = readl(regs + SPI_INT_STATUS);
+
+ while (status & (SPI_STATUS_TH | SPI_STATUS_RO)) {
+ dev_dbg(&drv_data->pdev->dev,
+ "interrupt_transfer - status = 0x%08X\n", status);
+
+ if (status & SPI_STATUS_RO) {
+ writel(readl(regs + SPI_INT_STATUS) & ~SPI_INTEN,
+ regs + SPI_INT_STATUS);
+
+ dev_warn(&drv_data->pdev->dev,
+ "interrupt_transfer - fifo overun\n"
+ " data not yet written = %d\n"
+ " data not yet read = %d\n",
+ data_to_write(drv_data),
+ data_to_read(drv_data));
+
+ if (flush(drv_data) == 0)
+ dev_err(&drv_data->pdev->dev,
+ "interrupt_transfer - flush failed\n");
+
+ msg->state = ERROR_STATE;
+ tasklet_schedule(&drv_data->pump_transfers);
+
+ return IRQ_HANDLED;
+ }
+
+ /* Pump data */
+ read(drv_data);
+ if (write(drv_data)) {
+ writel(readl(regs + SPI_INT_STATUS) & ~SPI_INTEN,
+ regs + SPI_INT_STATUS);
+
+ dev_dbg(&drv_data->pdev->dev,
+ "interrupt_transfer - end of tx\n");
+
+ /* Read trailing bytes */
+ limit = loops_per_jiffy << 1;
+ while ((read(drv_data) == 0) && limit--);
+
+ if (limit == 0)
+ dev_err(&drv_data->pdev->dev,
+ "interrupt_transfer - "
+ "trailing byte read failed\n");
+ else
+ dev_dbg(&drv_data->pdev->dev,
+ "interrupt_transfer - end of rx\n");
+
+ /* End of transfer, update total byte transfered */
+ msg->actual_length += drv_data->len;
+
+ /* Release chip select if requested, transfer delays are
+ handled in pump_transfers */
+ if (drv_data->cs_change)
+ drv_data->cs_control(SPI_CS_DEASSERT);
+
+ /* Move to next transfer */
+ msg->state = next_transfer(drv_data);
+
+ /* Schedule transfer tasklet */
+ tasklet_schedule(&drv_data->pump_transfers);
+
+ return IRQ_HANDLED;
+ }
+
+ status = readl(regs + SPI_INT_STATUS);
+
+ /* We did something */
+ handled = IRQ_HANDLED;
+ }
+
+ return handled;
+}
+
+static irqreturn_t spi_int(int irq, void *dev_id)
+{
+ struct driver_data *drv_data = (struct driver_data *)dev_id;
+
+ if (!drv_data->cur_msg) {
+ dev_err(&drv_data->pdev->dev,
+ "spi_int - bad message state\n");
+ /* Never fail */
+ return IRQ_HANDLED;
+ }
+
+ return drv_data->transfer_handler(drv_data);
+}
+
+static inline u32 spi_speed_hz(u32 data_rate)
+{
+ return imx_get_perclk2() / (4 << ((data_rate) >> 13));
+}
+
+static u32 spi_data_rate(u32 speed_hz)
+{
+ u32 div;
+ u32 quantized_hz = imx_get_perclk2() >> 2;
+
+ for (div = SPI_PERCLK2_DIV_MIN;
+ div <= SPI_PERCLK2_DIV_MAX;
+ div++, quantized_hz >>= 1) {
+ if (quantized_hz <= speed_hz)
+ /* Max available speed LEQ required speed */
+ return div << 13;
+ }
+ return SPI_CONTROL_DATARATE_BAD;
+}
+
+static void pump_transfers(unsigned long data)
+{
+ struct driver_data *drv_data = (struct driver_data *)data;
+ struct spi_message *message;
+ struct spi_transfer *transfer, *previous;
+ struct chip_data *chip;
+ void __iomem *regs;
+ u32 tmp, control;
+
+ dev_dbg(&drv_data->pdev->dev, "pump_transfer\n");
+
+ message = drv_data->cur_msg;
+
+ /* Handle for abort */
+ if (message->state == ERROR_STATE) {
+ message->status = -EIO;
+ giveback(message, drv_data);
+ return;
+ }
+
+ /* Handle end of message */
+ if (message->state == DONE_STATE) {
+ message->status = 0;
+ giveback(message, drv_data);
+ return;
+ }
+
+ chip = drv_data->cur_chip;
+
+ /* Delay if requested at end of transfer*/
+ transfer = drv_data->cur_transfer;
+ if (message->state == RUNNING_STATE) {
+ previous = list_entry(transfer->transfer_list.prev,
+ struct spi_transfer,
+ transfer_list);
+ if (previous->delay_usecs)
+ udelay(previous->delay_usecs);
+ } else {
+ /* START_STATE */
+ message->state = RUNNING_STATE;
+ drv_data->cs_control = chip->cs_control;
+ }
+
+ transfer = drv_data->cur_transfer;
+ drv_data->tx = (void *)transfer->tx_buf;
+ drv_data->tx_end = drv_data->tx + transfer->len;
+ drv_data->rx = transfer->rx_buf;
+ drv_data->rx_end = drv_data->rx + transfer->len;
+ drv_data->rx_dma = transfer->rx_dma;
+ drv_data->tx_dma = transfer->tx_dma;
+ drv_data->len = transfer->len;
+ drv_data->cs_change = transfer->cs_change;
+ drv_data->rd_only = (drv_data->tx == NULL);
+
+ regs = drv_data->regs;
+ control = readl(regs + SPI_CONTROL);
+
+ /* Bits per word setup */
+ tmp = transfer->bits_per_word;
+ if (tmp == 0) {
+ /* Use device setup */
+ tmp = chip->bits_per_word;
+ drv_data->n_bytes = chip->n_bytes;
+ } else
+ /* Use per-transfer setup */
+ drv_data->n_bytes = (tmp <= 8) ? 1 : 2;
+ u32_EDIT(control, SPI_CONTROL_BITCOUNT_MASK, tmp - 1);
+
+ /* Speed setup (surely valid because already checked) */
+ tmp = transfer->speed_hz;
+ if (tmp == 0)
+ tmp = chip->max_speed_hz;
+ tmp = spi_data_rate(tmp);
+ u32_EDIT(control, SPI_CONTROL_DATARATE, tmp);
+
+ writel(control, regs + SPI_CONTROL);
+
+ /* Assert device chip-select */
+ drv_data->cs_control(SPI_CS_ASSERT);
+
+ /* DMA cannot read/write SPI FIFOs other than 16 bits at a time; hence
+ if bits_per_word is less or equal 8 PIO transfers are performed.
+ Moreover DMA is convinient for transfer length bigger than FIFOs
+ byte size. */
+ if ((drv_data->n_bytes == 2) &&
+ (drv_data->len > SPI_FIFO_DEPTH*SPI_FIFO_BYTE_WIDTH) &&
+ (map_dma_buffers(drv_data) == 0)) {
+ dev_dbg(&drv_data->pdev->dev,
+ "pump dma transfer\n"
+ " tx = %p\n"
+ " tx_dma = %08X\n"
+ " rx = %p\n"
+ " rx_dma = %08X\n"
+ " len = %d\n",
+ drv_data->tx,
+ (unsigned int)drv_data->tx_dma,
+ drv_data->rx,
+ (unsigned int)drv_data->rx_dma,
+ drv_data->len);
+
+ /* Ensure we have the correct interrupt handler */
+ drv_data->transfer_handler = dma_transfer;
+
+ /* Trigger transfer */
+ writel(readl(regs + SPI_CONTROL) | SPI_CONTROL_XCH,
+ regs + SPI_CONTROL);
+
+ /* Setup tx DMA */
+ if (drv_data->tx)
+ /* Linear source address */
+ CCR(drv_data->tx_channel) =
+ CCR_DMOD_FIFO |
+ CCR_SMOD_LINEAR |
+ CCR_SSIZ_32 | CCR_DSIZ_16 |
+ CCR_REN;
+ else
+ /* Read only transfer -> fixed source address for
+ dummy write to achive read */
+ CCR(drv_data->tx_channel) =
+ CCR_DMOD_FIFO |
+ CCR_SMOD_FIFO |
+ CCR_SSIZ_32 | CCR_DSIZ_16 |
+ CCR_REN;
+
+ imx_dma_setup_single(
+ drv_data->tx_channel,
+ drv_data->tx_dma,
+ drv_data->len,
+ drv_data->rd_data_phys + 4,
+ DMA_MODE_WRITE);
+
+ if (drv_data->rx) {
+ /* Setup rx DMA for linear destination address */
+ CCR(drv_data->rx_channel) =
+ CCR_DMOD_LINEAR |
+ CCR_SMOD_FIFO |
+ CCR_DSIZ_32 | CCR_SSIZ_16 |
+ CCR_REN;
+ imx_dma_setup_single(
+ drv_data->rx_channel,
+ drv_data->rx_dma,
+ drv_data->len,
+ drv_data->rd_data_phys,
+ DMA_MODE_READ);
+ imx_dma_enable(drv_data->rx_channel);
+
+ /* Enable SPI interrupt */
+ writel(SPI_INTEN_RO, regs + SPI_INT_STATUS);
+
+ /* Set SPI to request DMA service on both
+ Rx and Tx half fifo watermark */
+ writel(SPI_DMA_RHDEN | SPI_DMA_THDEN, regs + SPI_DMA);
+ } else
+ /* Write only access -> set SPI to request DMA
+ service on Tx half fifo watermark */
+ writel(SPI_DMA_THDEN, regs + SPI_DMA);
+
+ imx_dma_enable(drv_data->tx_channel);
+ } else {
+ dev_dbg(&drv_data->pdev->dev,
+ "pump pio transfer\n"
+ " tx = %p\n"
+ " rx = %p\n"
+ " len = %d\n",
+ drv_data->tx,
+ drv_data->rx,
+ drv_data->len);
+
+ /* Ensure we have the correct interrupt handler */
+ if (drv_data->rx)
+ drv_data->transfer_handler = interrupt_transfer;
+ else
+ drv_data->transfer_handler = interrupt_wronly_transfer;
+
+ /* Enable SPI interrupt */
+ if (drv_data->rx)
+ writel(SPI_INTEN_TH | SPI_INTEN_RO,
+ regs + SPI_INT_STATUS);
+ else
+ writel(SPI_INTEN_TH, regs + SPI_INT_STATUS);
+ }
+}
+
+static void pump_messages(struct work_struct *work)
+{
+ struct driver_data *drv_data =
+ container_of(work, struct driver_data, work);
+ unsigned long flags;
+
+ /* Lock queue and check for queue work */
+ spin_lock_irqsave(&drv_data->lock, flags);
+ if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) {
+ drv_data->busy = 0;
+ spin_unlock_irqrestore(&drv_data->lock, flags);
+ return;
+ }
+
+ /* Make sure we are not already running a message */
+ if (drv_data->cur_msg) {
+ spin_unlock_irqrestore(&drv_data->lock, flags);
+ return;
+ }
+
+ /* Extract head of queue */
+ drv_data->cur_msg = list_entry(drv_data->queue.next,
+ struct spi_message, queue);
+ list_del_init(&drv_data->cur_msg->queue);
+ drv_data->busy = 1;
+ spin_unlock_irqrestore(&drv_data->lock, flags);
+
+ /* Initial message state */
+ drv_data->cur_msg->state = START_STATE;
+ drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
+ struct spi_transfer,
+ transfer_list);
+
+ /* Setup the SPI using the per chip configuration */
+ drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
+ restore_state(drv_data);
+
+ /* Mark as busy and launch transfers */
+ tasklet_schedule(&drv_data->pump_transfers);
+}
+
+static int transfer(struct spi_device *spi, struct spi_message *msg)
+{
+ struct driver_data *drv_data = spi_master_get_devdata(spi->master);
+ u32 min_speed_hz, max_speed_hz, tmp;
+ struct spi_transfer *trans;
+ unsigned long flags;
+
+ msg->actual_length = 0;
+
+ /* Per transfer setup check */
+ min_speed_hz = spi_speed_hz(SPI_CONTROL_DATARATE_MIN);
+ max_speed_hz = spi->max_speed_hz;
+ list_for_each_entry(trans, &msg->transfers, transfer_list) {
+ tmp = trans->bits_per_word;
+ if (tmp > 16) {
+ dev_err(&drv_data->pdev->dev,
+ "message rejected : "
+ "invalid transfer bits_per_word (%d bits)\n",
+ tmp);
+ goto msg_rejected;
+ }
+ tmp = trans->speed_hz;
+ if (tmp) {
+ if (tmp < min_speed_hz) {
+ dev_err(&drv_data->pdev->dev,
+ "message rejected : "
+ "device min speed (%d Hz) exceeds "
+ "required transfer speed (%d Hz)\n",
+ min_speed_hz,
+ tmp);
+ goto msg_rejected;
+ } else if (tmp > max_speed_hz) {
+ dev_err(&drv_data->pdev->dev,
+ "message rejected : "
+ "transfer speed (%d Hz) exceeds "
+ "device max speed (%d Hz)\n",
+ tmp,
+ max_speed_hz);
+ goto msg_rejected;
+ }
+ }
+ }
+
+ /* Message accepted */
+ msg->status = -EINPROGRESS;
+ msg->state = START_STATE;
+
+ spin_lock_irqsave(&drv_data->lock, flags);
+ if (drv_data->run == QUEUE_STOPPED) {
+ spin_unlock_irqrestore(&drv_data->lock, flags);
+ return -ESHUTDOWN;
+ }
+
+ list_add_tail(&msg->queue, &drv_data->queue);
+ if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
+ queue_work(drv_data->workqueue, &drv_data->work);
+
+ spin_unlock_irqrestore(&drv_data->lock, flags);
+ return 0;
+
+msg_rejected:
+ /* Message rejected and not queued */
+ msg->status = -EINVAL;
+ msg->state = ERROR_STATE;
+ if (msg->complete)
+ msg->complete(msg->context);
+ return -EINVAL;
+}
+
+/* On first setup bad values must free chip_data memory since will cause
+ spi_new_device to fail. Bad value setup from protocol driver are simply not
+ applied and notified to the calling driver. */
+static int setup(struct spi_device *spi)
+{
+ struct spi_imx_chip *chip_info;
+ struct chip_data *chip;
+ int first_setup = 0;
+ u32 tmp;
+ int status = 0;
+
+ /* Get controller data */
+ chip_info = spi->controller_data;
+
+ /* Get controller_state */
+ chip = spi_get_ctldata(spi);
+ if (chip == NULL) {
+ first_setup = 1;
+
+ chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
+ if (!chip) {
+ dev_err(&spi->dev,
+ "setup - cannot allocate controller state");
+ return -ENOMEM;
+ }
+ chip->control = SPI_DEFAULT_CONTROL;
+
+ if (chip_info == NULL) {
+ /* spi_board_info.controller_data not is supplied */
+ chip_info = kzalloc(sizeof(struct spi_imx_chip),
+ GFP_KERNEL);
+ if (!chip_info) {
+ dev_err(&spi->dev,
+ "setup - "
+ "cannot allocate controller data");
+ status = -ENOMEM;
+ goto err_first_setup;
+ }
+ /* Set controller data default value */
+ chip_info->enable_loopback =
+ SPI_DEFAULT_ENABLE_LOOPBACK;
+ chip_info->enable_dma = SPI_DEFAULT_ENABLE_DMA;
+ chip_info->ins_ss_pulse = 1;
+ chip_info->bclk_wait = SPI_DEFAULT_PERIOD_WAIT;
+ chip_info->cs_control = null_cs_control;
+ }
+ }
+
+ /* Now set controller state based on controller data */
+
+ if (first_setup) {
+ /* SPI loopback */
+ if (chip_info->enable_loopback)
+ chip->test = SPI_TEST_LBC;
+ else
+ chip->test = 0;
+
+ /* SPI dma driven */
+ chip->enable_dma = chip_info->enable_dma;
+
+ /* SPI /SS pulse between spi burst */
+ if (chip_info->ins_ss_pulse)
+ u32_EDIT(chip->control,
+ SPI_CONTROL_SSCTL, SPI_CONTROL_SSCTL_1);
+ else
+ u32_EDIT(chip->control,
+ SPI_CONTROL_SSCTL, SPI_CONTROL_SSCTL_0);
+
+ /* SPI bclk waits between each bits_per_word spi burst */
+ if (chip_info->bclk_wait > SPI_PERIOD_MAX_WAIT) {
+ dev_err(&spi->dev,
+ "setup - "
+ "bclk_wait exceeds max allowed (%d)\n",
+ SPI_PERIOD_MAX_WAIT);
+ goto err_first_setup;
+ }
+ chip->period = SPI_PERIOD_CSRC_BCLK |
+ (chip_info->bclk_wait & SPI_PERIOD_WAIT);
+ }
+
+ /* SPI mode */
+ tmp = spi->mode;
+ if (tmp & SPI_LSB_FIRST) {
+ status = -EINVAL;
+ if (first_setup) {
+ dev_err(&spi->dev,
+ "setup - "
+ "HW doesn't support LSB first transfer\n");
+ goto err_first_setup;
+ } else {
+ dev_err(&spi->dev,
+ "setup - "
+ "HW doesn't support LSB first transfer, "
+ "default to MSB first\n");
+ spi->mode &= ~SPI_LSB_FIRST;
+ }
+ }
+ if (tmp & SPI_CS_HIGH) {
+ u32_EDIT(chip->control,
+ SPI_CONTROL_SSPOL, SPI_CONTROL_SSPOL_ACT_HIGH);
+ }
+ switch (tmp & SPI_MODE_3) {
+ case SPI_MODE_0:
+ tmp = 0;
+ break;
+ case SPI_MODE_1:
+ tmp = SPI_CONTROL_PHA_1;
+ break;
+ case SPI_MODE_2:
+ tmp = SPI_CONTROL_POL_ACT_LOW;
+ break;
+ default:
+ /* SPI_MODE_3 */
+ tmp = SPI_CONTROL_PHA_1 | SPI_CONTROL_POL_ACT_LOW;
+ break;
+ }
+ u32_EDIT(chip->control, SPI_CONTROL_POL | SPI_CONTROL_PHA, tmp);
+
+ /* SPI word width */
+ tmp = spi->bits_per_word;
+ if (tmp == 0) {
+ tmp = 8;
+ spi->bits_per_word = 8;
+ } else if (tmp > 16) {
+ status = -EINVAL;
+ dev_err(&spi->dev,
+ "setup - "
+ "invalid bits_per_word (%d)\n",
+ tmp);
+ if (first_setup)
+ goto err_first_setup;
+ else {
+ /* Undo setup using chip as backup copy */
+ tmp = chip->bits_per_word;
+ spi->bits_per_word = tmp;
+ }
+ }
+ chip->bits_per_word = tmp;
+ u32_EDIT(chip->control, SPI_CONTROL_BITCOUNT_MASK, tmp - 1);
+ chip->n_bytes = (tmp <= 8) ? 1 : 2;
+
+ /* SPI datarate */
+ tmp = spi_data_rate(spi->max_speed_hz);
+ if (tmp == SPI_CONTROL_DATARATE_BAD) {
+ status = -EINVAL;
+ dev_err(&spi->dev,
+ "setup - "
+ "HW min speed (%d Hz) exceeds required "
+ "max speed (%d Hz)\n",
+ spi_speed_hz(SPI_CONTROL_DATARATE_MIN),
+ spi->max_speed_hz);
+ if (first_setup)
+ goto err_first_setup;
+ else
+ /* Undo setup using chip as backup copy */
+ spi->max_speed_hz = chip->max_speed_hz;
+ } else {
+ u32_EDIT(chip->control, SPI_CONTROL_DATARATE, tmp);
+ /* Actual rounded max_speed_hz */
+ tmp = spi_speed_hz(tmp);
+ spi->max_speed_hz = tmp;
+ chip->max_speed_hz = tmp;
+ }
+
+ /* SPI chip-select management */
+ if (chip_info->cs_control)
+ chip->cs_control = chip_info->cs_control;
+ else
+ chip->cs_control = null_cs_control;
+
+ /* Save controller_state */
+ spi_set_ctldata(spi, chip);
+
+ /* Summary */
+ dev_dbg(&spi->dev,
+ "setup succeded\n"
+ " loopback enable = %s\n"
+ " dma enable = %s\n"
+ " insert /ss pulse = %s\n"
+ " period wait = %d\n"
+ " mode = %d\n"
+ " bits per word = %d\n"
+ " min speed = %d Hz\n"
+ " rounded max speed = %d Hz\n",
+ chip->test & SPI_TEST_LBC ? "Yes" : "No",
+ chip->enable_dma ? "Yes" : "No",
+ chip->control & SPI_CONTROL_SSCTL ? "Yes" : "No",
+ chip->period & SPI_PERIOD_WAIT,
+ spi->mode,
+ spi->bits_per_word,
+ spi_speed_hz(SPI_CONTROL_DATARATE_MIN),
+ spi->max_speed_hz);
+
+err_first_setup:
+ kfree(chip);
+ return status;
+}
+
+static void cleanup(const struct spi_device *spi)
+{
+ struct chip_data *chip = spi_get_ctldata((struct spi_device *)spi);
+ kfree(chip);
+}
+
+static int init_queue(struct driver_data *drv_data)
+{
+ INIT_LIST_HEAD(&drv_data->queue);
+ spin_lock_init(&drv_data->lock);
+
+ drv_data->run = QUEUE_STOPPED;
+ drv_data->busy = 0;
+
+ tasklet_init(&drv_data->pump_transfers,
+ pump_transfers, (unsigned long)drv_data);
+
+ INIT_WORK(&drv_data->work, pump_messages);
+ drv_data->workqueue = create_singlethread_workqueue(
+ drv_data->master->cdev.dev->bus_id);
+ if (drv_data->workqueue == NULL)
+ return -EBUSY;
+
+ return 0;
+}
+
+static int start_queue(struct driver_data *drv_data)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&drv_data->lock, flags);
+
+ if (drv_data->run == QUEUE_RUNNING || drv_data->busy) {
+ spin_unlock_irqrestore(&drv_data->lock, flags);
+ return -EBUSY;
+ }
+
+ drv_data->run = QUEUE_RUNNING;
+ drv_data->cur_msg = NULL;
+ drv_data->cur_transfer = NULL;
+ drv_data->cur_chip = NULL;
+ spin_unlock_irqrestore(&drv_data->lock, flags);
+
+ queue_work(drv_data->workqueue, &drv_data->work);
+
+ return 0;
+}
+
+static int stop_queue(struct driver_data *drv_data)
+{
+ unsigned long flags;
+ unsigned limit = 500;
+ int status = 0;
+
+ spin_lock_irqsave(&drv_data->lock, flags);
+
+ /* This is a bit lame, but is optimized for the common execution path.
+ * A wait_queue on the drv_data->busy could be used, but then the common
+ * execution path (pump_messages) would be required to call wake_up or
+ * friends on every SPI message. Do this instead */
+ drv_data->run = QUEUE_STOPPED;
+ while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
+ spin_unlock_irqrestore(&drv_data->lock, flags);
+ msleep(10);
+ spin_lock_irqsave(&drv_data->lock, flags);
+ }
+
+ if (!list_empty(&drv_data->queue) || drv_data->busy)
+ status = -EBUSY;
+
+ spin_unlock_irqrestore(&drv_data->lock, flags);
+
+ return status;
+}
+
+static int destroy_queue(struct driver_data *drv_data)
+{
+ int status;
+
+ status = stop_queue(drv_data);
+ if (status != 0)
+ return status;
+
+ if (drv_data->workqueue)
+ destroy_workqueue(drv_data->workqueue);
+
+ return 0;
+}
+
+static int spi_imx_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct spi_imx_master *platform_info;
+ struct spi_master *master;
+ struct driver_data *drv_data = NULL;
+ struct resource *res;
+ int irq, status = 0;
+
+ platform_info = dev->platform_data;
+ if (platform_info == NULL) {
+ dev_err(&pdev->dev, "probe - no platform data supplied\n");
+ status = -ENODEV;
+ goto err_no_pdata;
+ }
+
+ /* Allocate master with space for drv_data */
+ master = spi_alloc_master(dev, sizeof(struct driver_data));
+ if (!master) {
+ dev_err(&pdev->dev, "probe - cannot alloc spi_master\n");
+ status = -ENOMEM;
+ goto err_no_mem;
+ }
+ drv_data = spi_master_get_devdata(master);
+ drv_data->master = master;
+ drv_data->master_info = platform_info;
+ drv_data->pdev = pdev;
+
+ master->bus_num = pdev->id;
+ master->num_chipselect = platform_info->num_chipselect;
+ master->cleanup = cleanup;
+ master->setup = setup;
+ master->transfer = transfer;
+
+ drv_data->dummy_dma_buf = SPI_DUMMY_u32;
+
+ /* Find and map resources */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "probe - MEM resources not defined\n");
+ status = -ENODEV;
+ goto err_no_iores;
+ }
+ drv_data->ioarea = request_mem_region(res->start,
+ res->end - res->start + 1,
+ pdev->name);
+ if (drv_data->ioarea == NULL) {
+ dev_err(&pdev->dev, "probe - cannot reserve region\n");
+ status = -ENXIO;
+ goto err_no_iores;
+ }
+ drv_data->regs = ioremap(res->start, res->end - res->start + 1);
+ if (drv_data->regs == NULL) {
+ dev_err(&pdev->dev, "probe - cannot map IO\n");
+ status = -ENXIO;
+ goto err_no_iomap;
+ }
+ drv_data->rd_data_phys = (dma_addr_t)res->start;
+
+ /* Attach to IRQ */
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "probe - IRQ resource not defined\n");
+ status = -ENODEV;
+ goto err_no_irqres;
+ }
+ status = request_irq(irq, spi_int, IRQF_DISABLED, dev->bus_id, drv_data);
+ if (status < 0) {
+ dev_err(&pdev->dev, "probe - cannot get IRQ (%d)\n", status);
+ goto err_no_irqres;
+ }
+
+ /* Setup DMA if requested */
+ drv_data->tx_channel = -1;
+ drv_data->rx_channel = -1;
+ if (platform_info->enable_dma) {
+ /* Get rx DMA channel */
+ status = imx_dma_request_by_prio(&drv_data->rx_channel,
+ "spi_imx_rx", DMA_PRIO_HIGH);
+ if (status < 0) {
+ dev_err(dev,
+ "probe - problem (%d) requesting rx channel\n",
+ status);
+ goto err_no_rxdma;
+ } else
+ imx_dma_setup_handlers(drv_data->rx_channel, NULL,
+ dma_err_handler, drv_data);
+
+ /* Get tx DMA channel */
+ status = imx_dma_request_by_prio(&drv_data->tx_channel,
+ "spi_imx_tx", DMA_PRIO_MEDIUM);
+ if (status < 0) {
+ dev_err(dev,
+ "probe - problem (%d) requesting tx channel\n",
+ status);
+ imx_dma_free(drv_data->rx_channel);
+ goto err_no_txdma;
+ } else
+ imx_dma_setup_handlers(drv_data->tx_channel,
+ dma_tx_handler, dma_err_handler,
+ drv_data);
+
+ /* Set request source and burst length for allocated channels */
+ switch (drv_data->pdev->id) {
+ case 1:
+ /* Using SPI1 */
+ RSSR(drv_data->rx_channel) = DMA_REQ_SPI1_R;
+ RSSR(drv_data->tx_channel) = DMA_REQ_SPI1_T;
+ break;
+ case 2:
+ /* Using SPI2 */
+ RSSR(drv_data->rx_channel) = DMA_REQ_SPI2_R;
+ RSSR(drv_data->tx_channel) = DMA_REQ_SPI2_T;
+ break;
+ default:
+ dev_err(dev, "probe - bad SPI Id\n");
+ imx_dma_free(drv_data->rx_channel);
+ imx_dma_free(drv_data->tx_channel);
+ status = -ENODEV;
+ goto err_no_devid;
+ }
+ BLR(drv_data->rx_channel) = SPI_DMA_BLR;
+ BLR(drv_data->tx_channel) = SPI_DMA_BLR;
+ }
+
+ /* Load default SPI configuration */
+ writel(SPI_RESET_START, drv_data->regs + SPI_RESET);
+ writel(0, drv_data->regs + SPI_RESET);
+ writel(SPI_DEFAULT_CONTROL, drv_data->regs + SPI_CONTROL);
+
+ /* Initial and start queue */
+ status = init_queue(drv_data);
+ if (status != 0) {
+ dev_err(&pdev->dev, "probe - problem initializing queue\n");
+ goto err_init_queue;
+ }
+ status = start_queue(drv_data);
+ if (status != 0) {
+ dev_err(&pdev->dev, "probe - problem starting queue\n");
+ goto err_start_queue;
+ }
+
+ /* Register with the SPI framework */
+ platform_set_drvdata(pdev, drv_data);
+ status = spi_register_master(master);
+ if (status != 0) {
+ dev_err(&pdev->dev, "probe - problem registering spi master\n");
+ goto err_spi_register;
+ }
+
+ dev_dbg(dev, "probe succeded\n");
+ return 0;
+
+err_init_queue:
+err_start_queue:
+err_spi_register:
+ destroy_queue(drv_data);
+
+err_no_rxdma:
+err_no_txdma:
+err_no_devid:
+ free_irq(irq, drv_data);
+
+err_no_irqres:
+ iounmap(drv_data->regs);
+
+err_no_iomap:
+ release_resource(drv_data->ioarea);
+ kfree(drv_data->ioarea);
+
+err_no_iores:
+ spi_master_put(master);
+
+err_no_pdata:
+err_no_mem:
+ return status;
+}
+
+static int __devexit spi_imx_remove(struct platform_device *pdev)
+{
+ struct driver_data *drv_data = platform_get_drvdata(pdev);
+ int irq;
+ int status = 0;
+
+ if (!drv_data)
+ return 0;
+
+ tasklet_kill(&drv_data->pump_transfers);
+
+ /* Remove the queue */
+ status = destroy_queue(drv_data);
+ if (status != 0) {
+ dev_err(&pdev->dev, "queue remove failed (%d)\n", status);
+ return status;
+ }
+
+ /* Reset SPI */
+ writel(SPI_RESET_START, drv_data->regs + SPI_RESET);
+ writel(0, drv_data->regs + SPI_RESET);
+
+ /* Release DMA */
+ if (drv_data->master_info->enable_dma) {
+ RSSR(drv_data->rx_channel) = 0;
+ RSSR(drv_data->tx_channel) = 0;
+ imx_dma_free(drv_data->tx_channel);
+ imx_dma_free(drv_data->rx_channel);
+ }
+
+ /* Release IRQ */
+ irq = platform_get_irq(pdev, 0);
+ if (irq >= 0)
+ free_irq(irq, drv_data);
+
+ /* Release map resources */
+ iounmap(drv_data->regs);
+ release_resource(drv_data->ioarea);
+ kfree(drv_data->ioarea);
+
+ /* Disconnect from the SPI framework */
+ spi_unregister_master(drv_data->master);
+ spi_master_put(drv_data->master);
+
+ /* Prevent double remove */
+ platform_set_drvdata(pdev, NULL);
+
+ dev_dbg(&pdev->dev, "remove succeded\n");
+
+ return 0;
+}
+
+static void spi_imx_shutdown(struct platform_device *pdev)
+{
+ struct driver_data *drv_data = platform_get_drvdata(pdev);
+
+ /* Reset SPI */
+ writel(SPI_RESET_START, drv_data->regs + SPI_RESET);
+ writel(0, drv_data->regs + SPI_RESET);
+
+ dev_dbg(&pdev->dev, "shutdown succeded\n");
+}
+
+#ifdef CONFIG_PM
+static int suspend_devices(struct device *dev, void *pm_message)
+{
+ pm_message_t *state = pm_message;
+
+ if (dev->power.power_state.event != state->event) {
+ dev_warn(dev, "pm state does not match request\n");
+ return -1;
+ }
+
+ return 0;
+}
+
+static int spi_imx_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ struct driver_data *drv_data = platform_get_drvdata(pdev);
+ int status = 0;
+
+ status = stop_queue(drv_data);
+ if (status != 0) {
+ dev_warn(&pdev->dev, "suspend cannot stop queue\n");
+ return status;
+ }
+
+ dev_dbg(&pdev->dev, "suspended\n");
+
+ return 0;
+}
+
+static int spi_imx_resume(struct platform_device *pdev)
+{
+ struct driver_data *drv_data = platform_get_drvdata(pdev);
+ int status = 0;
+
+ /* Start the queue running */
+ status = start_queue(drv_data);
+ if (status != 0)
+ dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
+ else
+ dev_dbg(&pdev->dev, "resumed\n");
+
+ return status;
+}
+#else
+#define spi_imx_suspend NULL
+#define spi_imx_resume NULL
+#endif /* CONFIG_PM */
+
+static struct platform_driver driver = {
+ .driver = {
+ .name = "imx-spi",
+ .bus = &platform_bus_type,
+ .owner = THIS_MODULE,
+ },
+ .probe = spi_imx_probe,
+ .remove = __devexit_p(spi_imx_remove),
+ .shutdown = spi_imx_shutdown,
+ .suspend = spi_imx_suspend,
+ .resume = spi_imx_resume,
+};
+
+static int __init spi_imx_init(void)
+{
+ return platform_driver_register(&driver);
+}
+module_init(spi_imx_init);
+
+static void __exit spi_imx_exit(void)
+{
+ platform_driver_unregister(&driver);
+}
+module_exit(spi_imx_exit);
+
+MODULE_AUTHOR("Andrea Paterniani, <a.paterniani@swapp-eng.it>");
+MODULE_DESCRIPTION("iMX SPI Contoller Driver");
+MODULE_LICENSE("GPL");
projects / linux-2.6 / commitdiff