+++ /dev/null
-/*
- * 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 <linux/clk.h>
-
-#include <asm/io.h>
-#include <asm/irq.h>
-#include <asm/delay.h>
-
-#include <mach/hardware.h>
-#include <mach/imx-dma.h>
-#include <mach/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 (0x1 << 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 length 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)
-#define DMA_ALIGNMENT 4
-/*-------------------------------------------------------------------------*/
-
-
-/*-------------------------------------------------------------------------*/
-/* 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;
-
- struct clk *clk;
-};
-
-/* 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 void flush(struct driver_data *drv_data)
-{
- void __iomem *regs = drv_data->regs;
- u32 control;
-
- dev_dbg(&drv_data->pdev->dev, "flush\n");
-
- /* Wait for end of transaction */
- do {
- control = readl(regs + SPI_CONTROL);
- } while (control & SPI_CONTROL_XCH);
-
- /* Release chip select if requested, transfer delays are
- handled in pump_transfers */
- if (drv_data->cs_change)
- drv_data->cs_control(SPI_CS_DEASSERT);
-
- /* Disable SPI to flush FIFOs */
- writel(control & ~SPI_CONTROL_SPIEN, regs + SPI_CONTROL);
- writel(control, regs + SPI_CONTROL);
-}
-
-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(dev, 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;
-
- 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(dev, drv_data->tx_dma))
- return -1;
- drv_data->tx_dma_needs_unmap = 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(dev, drv_data->rx_dma)) {
- if (drv_data->tx_dma) {
- dma_unmap_single(dev,
- drv_data->tx_dma,
- drv_data->tx_map_len,
- DMA_TO_DEVICE);
- drv_data->tx_dma_needs_unmap = 0;
- }
- return -1;
- }
- drv_data->rx_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);
-
- /* Unconditioned deselct */
- 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);
- unmap_dma_buffers(drv_data);
-
- flush(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(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;
-
- status = readl(regs + SPI_INT_STATUS);
-
- if ((status & (SPI_INTEN_RO | SPI_STATUS_RO))
- == (SPI_INTEN_RO | SPI_STATUS_RO)) {
- writel(status & ~SPI_INTEN, regs + SPI_INT_STATUS);
-
- imx_dma_disable(drv_data->tx_channel);
- imx_dma_disable(drv_data->rx_channel);
- unmap_dma_buffers(drv_data);
-
- flush(drv_data);
-
- 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 */
- while (readl(regs + SPI_CONTROL) & SPI_CONTROL_XCH)
- cpu_relax();
-
- imx_dma_disable(drv_data->rx_channel);
- unmap_dma_buffers(drv_data);
-
- /* Release chip select if requested, transfer delays are
- handled in pump_transfers() */
- if (drv_data->cs_change)
- drv_data->cs_control(SPI_CS_DEASSERT);
-
- /* 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);
-
- flush(drv_data);
- }
-
- /* End of transfer, update total byte transfered */
- msg->actual_length += drv_data->len;
-
- /* 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);
-
- if (status & SPI_INTEN_TE) {
- /* TXFIFO Empty Interrupt on the last transfered word */
- writel(status & ~SPI_INTEN, regs + SPI_INT_STATUS);
- dev_dbg(&drv_data->pdev->dev,
- "interrupt_wronly_transfer - end of tx\n");
-
- flush(drv_data);
-
- /* Update total byte transfered */
- msg->actual_length += drv_data->len;
-
- /* Move to next transfer */
- msg->state = next_transfer(drv_data);
-
- /* Schedule transfer tasklet */
- tasklet_schedule(&drv_data->pump_transfers);
-
- return IRQ_HANDLED;
- } else {
- 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)) {
- /* End of TXFIFO writes,
- now wait until TXFIFO is empty */
- writel(SPI_INTEN_TE, regs + SPI_INT_STATUS);
- 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, control;
- irqreturn_t handled = IRQ_NONE;
- unsigned long limit;
-
- status = readl(regs + SPI_INT_STATUS);
-
- if (status & SPI_INTEN_TE) {
- /* TXFIFO Empty Interrupt on the last transfered word */
- writel(status & ~SPI_INTEN, regs + SPI_INT_STATUS);
- dev_dbg(&drv_data->pdev->dev,
- "interrupt_transfer - end of tx\n");
-
- if (msg->state == ERROR_STATE) {
- /* RXFIFO overrun was detected and message aborted */
- flush(drv_data);
- } else {
- /* Wait for end of transaction */
- do {
- control = readl(regs + SPI_CONTROL);
- } while (control & SPI_CONTROL_XCH);
-
- /* Release chip select if requested, transfer delays are
- handled in pump_transfers */
- if (drv_data->cs_change)
- drv_data->cs_control(SPI_CS_DEASSERT);
-
- /* Read trailing bytes */
- limit = loops_per_jiffy << 1;
- while ((read(drv_data) == 0) && --limit)
- cpu_relax();
-
- 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");
-
- /* Update total byte transfered */
- msg->actual_length += drv_data->len;
-
- /* Move to next transfer */
- msg->state = next_transfer(drv_data);
- }
-
- /* Schedule transfer tasklet */
- tasklet_schedule(&drv_data->pump_transfers);
-
- return IRQ_HANDLED;
- } else {
- 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) {
- /* RXFIFO overrun, abort message end wait
- until TXFIFO is empty */
- writel(SPI_INTEN_TE, 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));
-
- msg->state = ERROR_STATE;
-
- return IRQ_HANDLED;
- }
-
- /* Pump data */
- read(drv_data);
- if (write(drv_data)) {
- /* End of TXFIFO writes,
- now wait until TXFIFO is empty */
- writel(SPI_INTEN_TE, regs + SPI_INT_STATUS);
- 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(struct driver_data *drv_data, u32 data_rate)
-{
- return clk_get_rate(drv_data->clk) / (4 << ((data_rate) >> 13));
-}
-
-static u32 spi_data_rate(struct driver_data *drv_data, u32 speed_hz)
-{
- u32 div;
- u32 quantized_hz = clk_get_rate(drv_data->clk) >> 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(drv_data, 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(drv_data, 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 driver_data *drv_data = spi_master_get_devdata(spi->master);
- 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\n");
- 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\n");
- 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_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 > 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(drv_data, 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(drv_data, 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(drv_data, 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(drv_data, SPI_CONTROL_DATARATE_MIN),
- spi->max_speed_hz);
- return status;
-
-err_first_setup:
- kfree(chip);
- return status;
-}
-
-static void cleanup(struct spi_device *spi)
-{
- kfree(spi_get_ctldata(spi));
-}
-
-static int __init 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(
- dev_name(drv_data->master->dev.parent));
- 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 __init 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;
- 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;
-
- /* the spi->mode bits understood by this driver: */
- master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
-
- master->bus_num = pdev->id;
- master->num_chipselect = platform_info->num_chipselect;
- master->dma_alignment = DMA_ALIGNMENT;
- master->cleanup = cleanup;
- master->setup = setup;
- master->transfer = transfer;
-
- drv_data->dummy_dma_buf = SPI_DUMMY_u32;
-
- drv_data->clk = clk_get(&pdev->dev, "perclk2");
- if (IS_ERR(drv_data->clk)) {
- dev_err(&pdev->dev, "probe - cannot get clock\n");
- status = PTR_ERR(drv_data->clk);
- goto err_no_clk;
- }
- clk_enable(drv_data->clk);
-
- /* 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_name(dev), 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 */
- drv_data->rx_channel = imx_dma_request_by_prio("spi_imx_rx",
- DMA_PRIO_HIGH);
- if (drv_data->rx_channel < 0) {
- dev_err(dev,
- "probe - problem (%d) requesting rx channel\n",
- drv_data->rx_channel);
- goto err_no_rxdma;
- } else
- imx_dma_setup_handlers(drv_data->rx_channel, NULL,
- dma_err_handler, drv_data);
-
- /* Get tx DMA channel */
- drv_data->tx_channel = imx_dma_request_by_prio("spi_imx_tx",
- DMA_PRIO_MEDIUM);
- if (drv_data->tx_channel < 0) {
- dev_err(dev,
- "probe - problem (%d) requesting tx channel\n",
- drv_data->tx_channel);
- 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:
- clk_disable(drv_data->clk);
- clk_put(drv_data->clk);
-
-err_no_clk:
- spi_master_put(master);
-
-err_no_pdata:
-err_no_mem:
- return status;
-}
-
-static int __exit 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);
-
- clk_disable(drv_data->clk);
- clk_put(drv_data->clk);
-
- /* 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 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 */
-
-/* work with hotplug and coldplug */
-MODULE_ALIAS("platform:spi_imx");
-
-static struct platform_driver driver = {
- .driver = {
- .name = "spi_imx",
- .owner = THIS_MODULE,
- },
- .remove = __exit_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_probe(&driver, spi_imx_probe);
-}
-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 Controller Driver");
-MODULE_LICENSE("GPL");
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff