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path: root/drivers/spi/pxa2xx_spi.c
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Diffstat (limited to 'drivers/spi/pxa2xx_spi.c')
-rw-r--r--drivers/spi/pxa2xx_spi.c1740
1 files changed, 1740 insertions, 0 deletions
diff --git a/drivers/spi/pxa2xx_spi.c b/drivers/spi/pxa2xx_spi.c
new file mode 100644
index 00000000..e76b1afa
--- /dev/null
+++ b/drivers/spi/pxa2xx_spi.c
@@ -0,0 +1,1740 @@
+/*
+ * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#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 <linux/gpio.h>
+#include <linux/slab.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/delay.h>
+
+#include <mach/dma.h>
+#include <plat/ssp.h>
+#include <mach/pxa2xx_spi.h>
+
+MODULE_AUTHOR("Stephen Street");
+MODULE_DESCRIPTION("PXA2xx SSP SPI Controller");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:pxa2xx-spi");
+
+#define MAX_BUSES 3
+
+#define RX_THRESH_DFLT 8
+#define TX_THRESH_DFLT 8
+#define TIMOUT_DFLT 1000
+
+#define DMA_INT_MASK (DCSR_ENDINTR | DCSR_STARTINTR | DCSR_BUSERR)
+#define RESET_DMA_CHANNEL (DCSR_NODESC | DMA_INT_MASK)
+#define IS_DMA_ALIGNED(x) ((((u32)(x)) & 0x07) == 0)
+#define MAX_DMA_LEN 8191
+#define DMA_ALIGNMENT 8
+
+/*
+ * for testing SSCR1 changes that require SSP restart, basically
+ * everything except the service and interrupt enables, the pxa270 developer
+ * manual says only SSCR1_SCFR, SSCR1_SPH, SSCR1_SPO need to be in this
+ * list, but the PXA255 dev man says all bits without really meaning the
+ * service and interrupt enables
+ */
+#define SSCR1_CHANGE_MASK (SSCR1_TTELP | SSCR1_TTE | SSCR1_SCFR \
+ | SSCR1_ECRA | SSCR1_ECRB | SSCR1_SCLKDIR \
+ | SSCR1_SFRMDIR | SSCR1_RWOT | SSCR1_TRAIL \
+ | SSCR1_IFS | SSCR1_STRF | SSCR1_EFWR \
+ | SSCR1_RFT | SSCR1_TFT | SSCR1_MWDS \
+ | SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
+
+#define DEFINE_SSP_REG(reg, off) \
+static inline u32 read_##reg(void const __iomem *p) \
+{ return __raw_readl(p + (off)); } \
+\
+static inline void write_##reg(u32 v, void __iomem *p) \
+{ __raw_writel(v, p + (off)); }
+
+DEFINE_SSP_REG(SSCR0, 0x00)
+DEFINE_SSP_REG(SSCR1, 0x04)
+DEFINE_SSP_REG(SSSR, 0x08)
+DEFINE_SSP_REG(SSITR, 0x0c)
+DEFINE_SSP_REG(SSDR, 0x10)
+DEFINE_SSP_REG(SSTO, 0x28)
+DEFINE_SSP_REG(SSPSP, 0x2c)
+
+#define START_STATE ((void*)0)
+#define RUNNING_STATE ((void*)1)
+#define DONE_STATE ((void*)2)
+#define ERROR_STATE ((void*)-1)
+
+#define QUEUE_RUNNING 0
+#define QUEUE_STOPPED 1
+
+struct driver_data {
+ /* Driver model hookup */
+ struct platform_device *pdev;
+
+ /* SSP Info */
+ struct ssp_device *ssp;
+
+ /* SPI framework hookup */
+ enum pxa_ssp_type ssp_type;
+ struct spi_master *master;
+
+ /* PXA hookup */
+ struct pxa2xx_spi_master *master_info;
+
+ /* DMA setup stuff */
+ int rx_channel;
+ int tx_channel;
+ u32 *null_dma_buf;
+
+ /* SSP register addresses */
+ void __iomem *ioaddr;
+ u32 ssdr_physical;
+
+ /* SSP masks*/
+ u32 dma_cr1;
+ u32 int_cr1;
+ u32 clear_sr;
+ u32 mask_sr;
+
+ /* Driver message queue */
+ struct workqueue_struct *workqueue;
+ struct work_struct pump_messages;
+ spinlock_t lock;
+ struct list_head queue;
+ int busy;
+ int run;
+
+ /* Message Transfer pump */
+ struct tasklet_struct pump_transfers;
+
+ /* Current message transfer state info */
+ struct spi_message* cur_msg;
+ struct spi_transfer* cur_transfer;
+ struct chip_data *cur_chip;
+ size_t len;
+ void *tx;
+ void *tx_end;
+ void *rx;
+ void *rx_end;
+ int dma_mapped;
+ dma_addr_t rx_dma;
+ dma_addr_t tx_dma;
+ size_t rx_map_len;
+ size_t tx_map_len;
+ u8 n_bytes;
+ u32 dma_width;
+ int (*write)(struct driver_data *drv_data);
+ int (*read)(struct driver_data *drv_data);
+ irqreturn_t (*transfer_handler)(struct driver_data *drv_data);
+ void (*cs_control)(u32 command);
+};
+
+struct chip_data {
+ u32 cr0;
+ u32 cr1;
+ u32 psp;
+ u32 timeout;
+ u8 n_bytes;
+ u32 dma_width;
+ u32 dma_burst_size;
+ u32 threshold;
+ u32 dma_threshold;
+ u8 enable_dma;
+ u8 bits_per_word;
+ u32 speed_hz;
+ int gpio_cs;
+ int gpio_cs_inverted;
+ int (*write)(struct driver_data *drv_data);
+ int (*read)(struct driver_data *drv_data);
+ void (*cs_control)(u32 command);
+};
+
+static void pump_messages(struct work_struct *work);
+
+static void cs_assert(struct driver_data *drv_data)
+{
+ struct chip_data *chip = drv_data->cur_chip;
+
+ if (chip->cs_control) {
+ chip->cs_control(PXA2XX_CS_ASSERT);
+ return;
+ }
+
+ if (gpio_is_valid(chip->gpio_cs))
+ gpio_set_value(chip->gpio_cs, chip->gpio_cs_inverted);
+}
+
+static void cs_deassert(struct driver_data *drv_data)
+{
+ struct chip_data *chip = drv_data->cur_chip;
+
+ if (chip->cs_control) {
+ chip->cs_control(PXA2XX_CS_DEASSERT);
+ return;
+ }
+
+ if (gpio_is_valid(chip->gpio_cs))
+ gpio_set_value(chip->gpio_cs, !chip->gpio_cs_inverted);
+}
+
+static int flush(struct driver_data *drv_data)
+{
+ unsigned long limit = loops_per_jiffy << 1;
+
+ void __iomem *reg = drv_data->ioaddr;
+
+ do {
+ while (read_SSSR(reg) & SSSR_RNE) {
+ read_SSDR(reg);
+ }
+ } while ((read_SSSR(reg) & SSSR_BSY) && --limit);
+ write_SSSR(SSSR_ROR, reg);
+
+ return limit;
+}
+
+static int null_writer(struct driver_data *drv_data)
+{
+ void __iomem *reg = drv_data->ioaddr;
+ u8 n_bytes = drv_data->n_bytes;
+
+ if (((read_SSSR(reg) & 0x00000f00) == 0x00000f00)
+ || (drv_data->tx == drv_data->tx_end))
+ return 0;
+
+ write_SSDR(0, reg);
+ drv_data->tx += n_bytes;
+
+ return 1;
+}
+
+static int null_reader(struct driver_data *drv_data)
+{
+ void __iomem *reg = drv_data->ioaddr;
+ u8 n_bytes = drv_data->n_bytes;
+
+ while ((read_SSSR(reg) & SSSR_RNE)
+ && (drv_data->rx < drv_data->rx_end)) {
+ read_SSDR(reg);
+ drv_data->rx += n_bytes;
+ }
+
+ return drv_data->rx == drv_data->rx_end;
+}
+
+static int u8_writer(struct driver_data *drv_data)
+{
+ void __iomem *reg = drv_data->ioaddr;
+
+ if (((read_SSSR(reg) & 0x00000f00) == 0x00000f00)
+ || (drv_data->tx == drv_data->tx_end))
+ return 0;
+
+ write_SSDR(*(u8 *)(drv_data->tx), reg);
+ ++drv_data->tx;
+
+ return 1;
+}
+
+static int u8_reader(struct driver_data *drv_data)
+{
+ void __iomem *reg = drv_data->ioaddr;
+
+ while ((read_SSSR(reg) & SSSR_RNE)
+ && (drv_data->rx < drv_data->rx_end)) {
+ *(u8 *)(drv_data->rx) = read_SSDR(reg);
+ ++drv_data->rx;
+ }
+
+ return drv_data->rx == drv_data->rx_end;
+}
+
+static int u16_writer(struct driver_data *drv_data)
+{
+ void __iomem *reg = drv_data->ioaddr;
+
+ if (((read_SSSR(reg) & 0x00000f00) == 0x00000f00)
+ || (drv_data->tx == drv_data->tx_end))
+ return 0;
+
+ write_SSDR(*(u16 *)(drv_data->tx), reg);
+ drv_data->tx += 2;
+
+ return 1;
+}
+
+static int u16_reader(struct driver_data *drv_data)
+{
+ void __iomem *reg = drv_data->ioaddr;
+
+ while ((read_SSSR(reg) & SSSR_RNE)
+ && (drv_data->rx < drv_data->rx_end)) {
+ *(u16 *)(drv_data->rx) = read_SSDR(reg);
+ drv_data->rx += 2;
+ }
+
+ return drv_data->rx == drv_data->rx_end;
+}
+
+static int u32_writer(struct driver_data *drv_data)
+{
+ void __iomem *reg = drv_data->ioaddr;
+
+ if (((read_SSSR(reg) & 0x00000f00) == 0x00000f00)
+ || (drv_data->tx == drv_data->tx_end))
+ return 0;
+
+ write_SSDR(*(u32 *)(drv_data->tx), reg);
+ drv_data->tx += 4;
+
+ return 1;
+}
+
+static int u32_reader(struct driver_data *drv_data)
+{
+ void __iomem *reg = drv_data->ioaddr;
+
+ while ((read_SSSR(reg) & SSSR_RNE)
+ && (drv_data->rx < drv_data->rx_end)) {
+ *(u32 *)(drv_data->rx) = read_SSDR(reg);
+ drv_data->rx += 4;
+ }
+
+ return drv_data->rx == drv_data->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;
+ } else
+ return DONE_STATE;
+}
+
+static int map_dma_buffers(struct driver_data *drv_data)
+{
+ struct spi_message *msg = drv_data->cur_msg;
+ struct device *dev = &msg->spi->dev;
+
+ if (!drv_data->cur_chip->enable_dma)
+ return 0;
+
+ if (msg->is_dma_mapped)
+ return drv_data->rx_dma && drv_data->tx_dma;
+
+ if (!IS_DMA_ALIGNED(drv_data->rx) || !IS_DMA_ALIGNED(drv_data->tx))
+ return 0;
+
+ /* Modify setup if rx buffer is null */
+ if (drv_data->rx == NULL) {
+ *drv_data->null_dma_buf = 0;
+ drv_data->rx = drv_data->null_dma_buf;
+ drv_data->rx_map_len = 4;
+ } else
+ drv_data->rx_map_len = drv_data->len;
+
+
+ /* Modify setup if tx buffer is null */
+ if (drv_data->tx == NULL) {
+ *drv_data->null_dma_buf = 0;
+ drv_data->tx = drv_data->null_dma_buf;
+ drv_data->tx_map_len = 4;
+ } else
+ drv_data->tx_map_len = drv_data->len;
+
+ /* Stream map the tx buffer. Always do DMA_TO_DEVICE first
+ * so we flush the cache *before* invalidating it, in case
+ * the tx and rx buffers overlap.
+ */
+ drv_data->tx_dma = dma_map_single(dev, drv_data->tx,
+ drv_data->tx_map_len, DMA_TO_DEVICE);
+ if (dma_mapping_error(dev, drv_data->tx_dma))
+ return 0;
+
+ /* Stream map the rx buffer */
+ drv_data->rx_dma = dma_map_single(dev, drv_data->rx,
+ drv_data->rx_map_len, DMA_FROM_DEVICE);
+ if (dma_mapping_error(dev, drv_data->rx_dma)) {
+ dma_unmap_single(dev, drv_data->tx_dma,
+ drv_data->tx_map_len, DMA_TO_DEVICE);
+ return 0;
+ }
+
+ return 1;
+}
+
+static void unmap_dma_buffers(struct driver_data *drv_data)
+{
+ struct device *dev;
+
+ if (!drv_data->dma_mapped)
+ return;
+
+ if (!drv_data->cur_msg->is_dma_mapped) {
+ dev = &drv_data->cur_msg->spi->dev;
+ dma_unmap_single(dev, drv_data->rx_dma,
+ drv_data->rx_map_len, DMA_FROM_DEVICE);
+ dma_unmap_single(dev, drv_data->tx_dma,
+ drv_data->tx_map_len, DMA_TO_DEVICE);
+ }
+
+ drv_data->dma_mapped = 0;
+}
+
+/* caller already set message->status; dma and pio irqs are blocked */
+static void giveback(struct driver_data *drv_data)
+{
+ struct spi_transfer* last_transfer;
+ unsigned long flags;
+ struct spi_message *msg;
+
+ spin_lock_irqsave(&drv_data->lock, flags);
+ msg = drv_data->cur_msg;
+ drv_data->cur_msg = NULL;
+ drv_data->cur_transfer = NULL;
+ queue_work(drv_data->workqueue, &drv_data->pump_messages);
+ spin_unlock_irqrestore(&drv_data->lock, flags);
+
+ last_transfer = list_entry(msg->transfers.prev,
+ struct spi_transfer,
+ transfer_list);
+
+ /* Delay if requested before any change in chip select */
+ if (last_transfer->delay_usecs)
+ udelay(last_transfer->delay_usecs);
+
+ /* Drop chip select UNLESS cs_change is true or we are returning
+ * a message with an error, or next message is for another chip
+ */
+ if (!last_transfer->cs_change)
+ cs_deassert(drv_data);
+ else {
+ struct spi_message *next_msg;
+
+ /* Holding of cs was hinted, but we need to make sure
+ * the next message is for the same chip. Don't waste
+ * time with the following tests unless this was hinted.
+ *
+ * We cannot postpone this until pump_messages, because
+ * after calling msg->complete (below) the driver that
+ * sent the current message could be unloaded, which
+ * could invalidate the cs_control() callback...
+ */
+
+ /* get a pointer to the next message, if any */
+ spin_lock_irqsave(&drv_data->lock, flags);
+ if (list_empty(&drv_data->queue))
+ next_msg = NULL;
+ else
+ next_msg = list_entry(drv_data->queue.next,
+ struct spi_message, queue);
+ spin_unlock_irqrestore(&drv_data->lock, flags);
+
+ /* see if the next and current messages point
+ * to the same chip
+ */
+ if (next_msg && next_msg->spi != msg->spi)
+ next_msg = NULL;
+ if (!next_msg || msg->state == ERROR_STATE)
+ cs_deassert(drv_data);
+ }
+
+ msg->state = NULL;
+ if (msg->complete)
+ msg->complete(msg->context);
+
+ drv_data->cur_chip = NULL;
+}
+
+static int wait_ssp_rx_stall(void const __iomem *ioaddr)
+{
+ unsigned long limit = loops_per_jiffy << 1;
+
+ while ((read_SSSR(ioaddr) & SSSR_BSY) && --limit)
+ cpu_relax();
+
+ return limit;
+}
+
+static int wait_dma_channel_stop(int channel)
+{
+ unsigned long limit = loops_per_jiffy << 1;
+
+ while (!(DCSR(channel) & DCSR_STOPSTATE) && --limit)
+ cpu_relax();
+
+ return limit;
+}
+
+static void dma_error_stop(struct driver_data *drv_data, const char *msg)
+{
+ void __iomem *reg = drv_data->ioaddr;
+
+ /* Stop and reset */
+ DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
+ DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
+ write_SSSR(drv_data->clear_sr, reg);
+ write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
+ if (drv_data->ssp_type != PXA25x_SSP)
+ write_SSTO(0, reg);
+ flush(drv_data);
+ write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
+
+ unmap_dma_buffers(drv_data);
+
+ dev_err(&drv_data->pdev->dev, "%s\n", msg);
+
+ drv_data->cur_msg->state = ERROR_STATE;
+ tasklet_schedule(&drv_data->pump_transfers);
+}
+
+static void dma_transfer_complete(struct driver_data *drv_data)
+{
+ void __iomem *reg = drv_data->ioaddr;
+ struct spi_message *msg = drv_data->cur_msg;
+
+ /* Clear and disable interrupts on SSP and DMA channels*/
+ write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
+ write_SSSR(drv_data->clear_sr, reg);
+ DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
+ DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
+
+ if (wait_dma_channel_stop(drv_data->rx_channel) == 0)
+ dev_err(&drv_data->pdev->dev,
+ "dma_handler: dma rx channel stop failed\n");
+
+ if (wait_ssp_rx_stall(drv_data->ioaddr) == 0)
+ dev_err(&drv_data->pdev->dev,
+ "dma_transfer: ssp rx stall failed\n");
+
+ unmap_dma_buffers(drv_data);
+
+ /* update the buffer pointer for the amount completed in dma */
+ drv_data->rx += drv_data->len -
+ (DCMD(drv_data->rx_channel) & DCMD_LENGTH);
+
+ /* read trailing data from fifo, it does not matter how many
+ * bytes are in the fifo just read until buffer is full
+ * or fifo is empty, which ever occurs first */
+ drv_data->read(drv_data);
+
+ /* return count of what was actually read */
+ msg->actual_length += drv_data->len -
+ (drv_data->rx_end - drv_data->rx);
+
+ /* Transfer delays and chip select release are
+ * handled in pump_transfers or giveback
+ */
+
+ /* Move to next transfer */
+ msg->state = next_transfer(drv_data);
+
+ /* Schedule transfer tasklet */
+ tasklet_schedule(&drv_data->pump_transfers);
+}
+
+static void dma_handler(int channel, void *data)
+{
+ struct driver_data *drv_data = data;
+ u32 irq_status = DCSR(channel) & DMA_INT_MASK;
+
+ if (irq_status & DCSR_BUSERR) {
+
+ if (channel == drv_data->tx_channel)
+ dma_error_stop(drv_data,
+ "dma_handler: "
+ "bad bus address on tx channel");
+ else
+ dma_error_stop(drv_data,
+ "dma_handler: "
+ "bad bus address on rx channel");
+ return;
+ }
+
+ /* PXA255x_SSP has no timeout interrupt, wait for tailing bytes */
+ if ((channel == drv_data->tx_channel)
+ && (irq_status & DCSR_ENDINTR)
+ && (drv_data->ssp_type == PXA25x_SSP)) {
+
+ /* Wait for rx to stall */
+ if (wait_ssp_rx_stall(drv_data->ioaddr) == 0)
+ dev_err(&drv_data->pdev->dev,
+ "dma_handler: ssp rx stall failed\n");
+
+ /* finish this transfer, start the next */
+ dma_transfer_complete(drv_data);
+ }
+}
+
+static irqreturn_t dma_transfer(struct driver_data *drv_data)
+{
+ u32 irq_status;
+ void __iomem *reg = drv_data->ioaddr;
+
+ irq_status = read_SSSR(reg) & drv_data->mask_sr;
+ if (irq_status & SSSR_ROR) {
+ dma_error_stop(drv_data, "dma_transfer: fifo overrun");
+ return IRQ_HANDLED;
+ }
+
+ /* Check for false positive timeout */
+ if ((irq_status & SSSR_TINT)
+ && (DCSR(drv_data->tx_channel) & DCSR_RUN)) {
+ write_SSSR(SSSR_TINT, reg);
+ return IRQ_HANDLED;
+ }
+
+ if (irq_status & SSSR_TINT || drv_data->rx == drv_data->rx_end) {
+
+ /* Clear and disable timeout interrupt, do the rest in
+ * dma_transfer_complete */
+ if (drv_data->ssp_type != PXA25x_SSP)
+ write_SSTO(0, reg);
+
+ /* finish this transfer, start the next */
+ dma_transfer_complete(drv_data);
+
+ return IRQ_HANDLED;
+ }
+
+ /* Opps problem detected */
+ return IRQ_NONE;
+}
+
+static void int_error_stop(struct driver_data *drv_data, const char* msg)
+{
+ void __iomem *reg = drv_data->ioaddr;
+
+ /* Stop and reset SSP */
+ write_SSSR(drv_data->clear_sr, reg);
+ write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
+ if (drv_data->ssp_type != PXA25x_SSP)
+ write_SSTO(0, reg);
+ flush(drv_data);
+ write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
+
+ dev_err(&drv_data->pdev->dev, "%s\n", msg);
+
+ drv_data->cur_msg->state = ERROR_STATE;
+ tasklet_schedule(&drv_data->pump_transfers);
+}
+
+static void int_transfer_complete(struct driver_data *drv_data)
+{
+ void __iomem *reg = drv_data->ioaddr;
+
+ /* Stop SSP */
+ write_SSSR(drv_data->clear_sr, reg);
+ write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
+ if (drv_data->ssp_type != PXA25x_SSP)
+ write_SSTO(0, reg);
+
+ /* Update total byte transfered return count actual bytes read */
+ drv_data->cur_msg->actual_length += drv_data->len -
+ (drv_data->rx_end - drv_data->rx);
+
+ /* Transfer delays and chip select release are
+ * handled in pump_transfers or giveback
+ */
+
+ /* Move to next transfer */
+ drv_data->cur_msg->state = next_transfer(drv_data);
+
+ /* Schedule transfer tasklet */
+ tasklet_schedule(&drv_data->pump_transfers);
+}
+
+static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
+{
+ void __iomem *reg = drv_data->ioaddr;
+
+ u32 irq_mask = (read_SSCR1(reg) & SSCR1_TIE) ?
+ drv_data->mask_sr : drv_data->mask_sr & ~SSSR_TFS;
+
+ u32 irq_status = read_SSSR(reg) & irq_mask;
+
+ if (irq_status & SSSR_ROR) {
+ int_error_stop(drv_data, "interrupt_transfer: fifo overrun");
+ return IRQ_HANDLED;
+ }
+
+ if (irq_status & SSSR_TINT) {
+ write_SSSR(SSSR_TINT, reg);
+ if (drv_data->read(drv_data)) {
+ int_transfer_complete(drv_data);
+ return IRQ_HANDLED;
+ }
+ }
+
+ /* Drain rx fifo, Fill tx fifo and prevent overruns */
+ do {
+ if (drv_data->read(drv_data)) {
+ int_transfer_complete(drv_data);
+ return IRQ_HANDLED;
+ }
+ } while (drv_data->write(drv_data));
+
+ if (drv_data->read(drv_data)) {
+ int_transfer_complete(drv_data);
+ return IRQ_HANDLED;
+ }
+
+ if (drv_data->tx == drv_data->tx_end) {
+ write_SSCR1(read_SSCR1(reg) & ~SSCR1_TIE, reg);
+ /* PXA25x_SSP has no timeout, read trailing bytes */
+ if (drv_data->ssp_type == PXA25x_SSP) {
+ if (!wait_ssp_rx_stall(reg))
+ {
+ int_error_stop(drv_data, "interrupt_transfer: "
+ "rx stall failed");
+ return IRQ_HANDLED;
+ }
+ if (!drv_data->read(drv_data))
+ {
+ int_error_stop(drv_data,
+ "interrupt_transfer: "
+ "trailing byte read failed");
+ return IRQ_HANDLED;
+ }
+ int_transfer_complete(drv_data);
+ }
+ }
+
+ /* We did something */
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t ssp_int(int irq, void *dev_id)
+{
+ struct driver_data *drv_data = dev_id;
+ void __iomem *reg = drv_data->ioaddr;
+
+ if (!drv_data->cur_msg) {
+
+ write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
+ write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
+ if (drv_data->ssp_type != PXA25x_SSP)
+ write_SSTO(0, reg);
+ write_SSSR(drv_data->clear_sr, reg);
+
+ dev_err(&drv_data->pdev->dev, "bad message state "
+ "in interrupt handler\n");
+
+ /* Never fail */
+ return IRQ_HANDLED;
+ }
+
+ return drv_data->transfer_handler(drv_data);
+}
+
+static int set_dma_burst_and_threshold(struct chip_data *chip,
+ struct spi_device *spi,
+ u8 bits_per_word, u32 *burst_code,
+ u32 *threshold)
+{
+ struct pxa2xx_spi_chip *chip_info =
+ (struct pxa2xx_spi_chip *)spi->controller_data;
+ int bytes_per_word;
+ int burst_bytes;
+ int thresh_words;
+ int req_burst_size;
+ int retval = 0;
+
+ /* Set the threshold (in registers) to equal the same amount of data
+ * as represented by burst size (in bytes). The computation below
+ * is (burst_size rounded up to nearest 8 byte, word or long word)
+ * divided by (bytes/register); the tx threshold is the inverse of
+ * the rx, so that there will always be enough data in the rx fifo
+ * to satisfy a burst, and there will always be enough space in the
+ * tx fifo to accept a burst (a tx burst will overwrite the fifo if
+ * there is not enough space), there must always remain enough empty
+ * space in the rx fifo for any data loaded to the tx fifo.
+ * Whenever burst_size (in bytes) equals bits/word, the fifo threshold
+ * will be 8, or half the fifo;
+ * The threshold can only be set to 2, 4 or 8, but not 16, because
+ * to burst 16 to the tx fifo, the fifo would have to be empty;
+ * however, the minimum fifo trigger level is 1, and the tx will
+ * request service when the fifo is at this level, with only 15 spaces.
+ */
+
+ /* find bytes/word */
+ if (bits_per_word <= 8)
+ bytes_per_word = 1;
+ else if (bits_per_word <= 16)
+ bytes_per_word = 2;
+ else
+ bytes_per_word = 4;
+
+ /* use struct pxa2xx_spi_chip->dma_burst_size if available */
+ if (chip_info)
+ req_burst_size = chip_info->dma_burst_size;
+ else {
+ switch (chip->dma_burst_size) {
+ default:
+ /* if the default burst size is not set,
+ * do it now */
+ chip->dma_burst_size = DCMD_BURST8;
+ case DCMD_BURST8:
+ req_burst_size = 8;
+ break;
+ case DCMD_BURST16:
+ req_burst_size = 16;
+ break;
+ case DCMD_BURST32:
+ req_burst_size = 32;
+ break;
+ }
+ }
+ if (req_burst_size <= 8) {
+ *burst_code = DCMD_BURST8;
+ burst_bytes = 8;
+ } else if (req_burst_size <= 16) {
+ if (bytes_per_word == 1) {
+ /* don't burst more than 1/2 the fifo */
+ *burst_code = DCMD_BURST8;
+ burst_bytes = 8;
+ retval = 1;
+ } else {
+ *burst_code = DCMD_BURST16;
+ burst_bytes = 16;
+ }
+ } else {
+ if (bytes_per_word == 1) {
+ /* don't burst more than 1/2 the fifo */
+ *burst_code = DCMD_BURST8;
+ burst_bytes = 8;
+ retval = 1;
+ } else if (bytes_per_word == 2) {
+ /* don't burst more than 1/2 the fifo */
+ *burst_code = DCMD_BURST16;
+ burst_bytes = 16;
+ retval = 1;
+ } else {
+ *burst_code = DCMD_BURST32;
+ burst_bytes = 32;
+ }
+ }
+
+ thresh_words = burst_bytes / bytes_per_word;
+
+ /* thresh_words will be between 2 and 8 */
+ *threshold = (SSCR1_RxTresh(thresh_words) & SSCR1_RFT)
+ | (SSCR1_TxTresh(16-thresh_words) & SSCR1_TFT);
+
+ return retval;
+}
+
+static unsigned int ssp_get_clk_div(struct ssp_device *ssp, int rate)
+{
+ unsigned long ssp_clk = clk_get_rate(ssp->clk);
+
+ if (ssp->type == PXA25x_SSP)
+ return ((ssp_clk / (2 * rate) - 1) & 0xff) << 8;
+ else
+ return ((ssp_clk / rate - 1) & 0xfff) << 8;
+}
+
+static void pump_transfers(unsigned long data)
+{
+ struct driver_data *drv_data = (struct driver_data *)data;
+ struct spi_message *message = NULL;
+ struct spi_transfer *transfer = NULL;
+ struct spi_transfer *previous = NULL;
+ struct chip_data *chip = NULL;
+ struct ssp_device *ssp = drv_data->ssp;
+ void __iomem *reg = drv_data->ioaddr;
+ u32 clk_div = 0;
+ u8 bits = 0;
+ u32 speed = 0;
+ u32 cr0;
+ u32 cr1;
+ u32 dma_thresh = drv_data->cur_chip->dma_threshold;
+ u32 dma_burst = drv_data->cur_chip->dma_burst_size;
+
+ /* Get current state information */
+ message = drv_data->cur_msg;
+ transfer = drv_data->cur_transfer;
+ chip = drv_data->cur_chip;
+
+ /* Handle for abort */
+ if (message->state == ERROR_STATE) {
+ message->status = -EIO;
+ giveback(drv_data);
+ return;
+ }
+
+ /* Handle end of message */
+ if (message->state == DONE_STATE) {
+ message->status = 0;
+ giveback(drv_data);
+ return;
+ }
+
+ /* Delay if requested at end of transfer before CS change */
+ 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);
+
+ /* Drop chip select only if cs_change is requested */
+ if (previous->cs_change)
+ cs_deassert(drv_data);
+ }
+
+ /* Check for transfers that need multiple DMA segments */
+ if (transfer->len > MAX_DMA_LEN && chip->enable_dma) {
+
+ /* reject already-mapped transfers; PIO won't always work */
+ if (message->is_dma_mapped
+ || transfer->rx_dma || transfer->tx_dma) {
+ dev_err(&drv_data->pdev->dev,
+ "pump_transfers: mapped transfer length "
+ "of %u is greater than %d\n",
+ transfer->len, MAX_DMA_LEN);
+ message->status = -EINVAL;
+ giveback(drv_data);
+ return;
+ }
+
+ /* warn ... we force this to PIO mode */
+ if (printk_ratelimit())
+ dev_warn(&message->spi->dev, "pump_transfers: "
+ "DMA disabled for transfer length %ld "
+ "greater than %d\n",
+ (long)drv_data->len, MAX_DMA_LEN);
+ }
+
+ /* Setup the transfer state based on the type of transfer */
+ if (flush(drv_data) == 0) {
+ dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
+ message->status = -EIO;
+ giveback(drv_data);
+ return;
+ }
+ drv_data->n_bytes = chip->n_bytes;
+ drv_data->dma_width = chip->dma_width;
+ 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 & DCMD_LENGTH;
+ drv_data->write = drv_data->tx ? chip->write : null_writer;
+ drv_data->read = drv_data->rx ? chip->read : null_reader;
+
+ /* Change speed and bit per word on a per transfer */
+ cr0 = chip->cr0;
+ if (transfer->speed_hz || transfer->bits_per_word) {
+
+ bits = chip->bits_per_word;
+ speed = chip->speed_hz;
+
+ if (transfer->speed_hz)
+ speed = transfer->speed_hz;
+
+ if (transfer->bits_per_word)
+ bits = transfer->bits_per_word;
+
+ clk_div = ssp_get_clk_div(ssp, speed);
+
+ if (bits <= 8) {
+ drv_data->n_bytes = 1;
+ drv_data->dma_width = DCMD_WIDTH1;
+ drv_data->read = drv_data->read != null_reader ?
+ u8_reader : null_reader;
+ drv_data->write = drv_data->write != null_writer ?
+ u8_writer : null_writer;
+ } else if (bits <= 16) {
+ drv_data->n_bytes = 2;
+ drv_data->dma_width = DCMD_WIDTH2;
+ drv_data->read = drv_data->read != null_reader ?
+ u16_reader : null_reader;
+ drv_data->write = drv_data->write != null_writer ?
+ u16_writer : null_writer;
+ } else if (bits <= 32) {
+ drv_data->n_bytes = 4;
+ drv_data->dma_width = DCMD_WIDTH4;
+ drv_data->read = drv_data->read != null_reader ?
+ u32_reader : null_reader;
+ drv_data->write = drv_data->write != null_writer ?
+ u32_writer : null_writer;
+ }
+ /* if bits/word is changed in dma mode, then must check the
+ * thresholds and burst also */
+ if (chip->enable_dma) {
+ if (set_dma_burst_and_threshold(chip, message->spi,
+ bits, &dma_burst,
+ &dma_thresh))
+ if (printk_ratelimit())
+ dev_warn(&message->spi->dev,
+ "pump_transfers: "
+ "DMA burst size reduced to "
+ "match bits_per_word\n");
+ }
+
+ cr0 = clk_div
+ | SSCR0_Motorola
+ | SSCR0_DataSize(bits > 16 ? bits - 16 : bits)
+ | SSCR0_SSE
+ | (bits > 16 ? SSCR0_EDSS : 0);
+ }
+
+ message->state = RUNNING_STATE;
+
+ /* Try to map dma buffer and do a dma transfer if successful, but
+ * only if the length is non-zero and less than MAX_DMA_LEN.
+ *
+ * Zero-length non-descriptor DMA is illegal on PXA2xx; force use
+ * of PIO instead. Care is needed above because the transfer may
+ * have have been passed with buffers that are already dma mapped.
+ * A zero-length transfer in PIO mode will not try to write/read
+ * to/from the buffers
+ *
+ * REVISIT large transfers are exactly where we most want to be
+ * using DMA. If this happens much, split those transfers into
+ * multiple DMA segments rather than forcing PIO.
+ */
+ drv_data->dma_mapped = 0;
+ if (drv_data->len > 0 && drv_data->len <= MAX_DMA_LEN)
+ drv_data->dma_mapped = map_dma_buffers(drv_data);
+ if (drv_data->dma_mapped) {
+
+ /* Ensure we have the correct interrupt handler */
+ drv_data->transfer_handler = dma_transfer;
+
+ /* Setup rx DMA Channel */
+ DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
+ DSADR(drv_data->rx_channel) = drv_data->ssdr_physical;
+ DTADR(drv_data->rx_channel) = drv_data->rx_dma;
+ if (drv_data->rx == drv_data->null_dma_buf)
+ /* No target address increment */
+ DCMD(drv_data->rx_channel) = DCMD_FLOWSRC
+ | drv_data->dma_width
+ | dma_burst
+ | drv_data->len;
+ else
+ DCMD(drv_data->rx_channel) = DCMD_INCTRGADDR
+ | DCMD_FLOWSRC
+ | drv_data->dma_width
+ | dma_burst
+ | drv_data->len;
+
+ /* Setup tx DMA Channel */
+ DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
+ DSADR(drv_data->tx_channel) = drv_data->tx_dma;
+ DTADR(drv_data->tx_channel) = drv_data->ssdr_physical;
+ if (drv_data->tx == drv_data->null_dma_buf)
+ /* No source address increment */
+ DCMD(drv_data->tx_channel) = DCMD_FLOWTRG
+ | drv_data->dma_width
+ | dma_burst
+ | drv_data->len;
+ else
+ DCMD(drv_data->tx_channel) = DCMD_INCSRCADDR
+ | DCMD_FLOWTRG
+ | drv_data->dma_width
+ | dma_burst
+ | drv_data->len;
+
+ /* Enable dma end irqs on SSP to detect end of transfer */
+ if (drv_data->ssp_type == PXA25x_SSP)
+ DCMD(drv_data->tx_channel) |= DCMD_ENDIRQEN;
+
+ /* Clear status and start DMA engine */
+ cr1 = chip->cr1 | dma_thresh | drv_data->dma_cr1;
+ write_SSSR(drv_data->clear_sr, reg);
+ DCSR(drv_data->rx_channel) |= DCSR_RUN;
+ DCSR(drv_data->tx_channel) |= DCSR_RUN;
+ } else {
+ /* Ensure we have the correct interrupt handler */
+ drv_data->transfer_handler = interrupt_transfer;
+
+ /* Clear status */
+ cr1 = chip->cr1 | chip->threshold | drv_data->int_cr1;
+ write_SSSR(drv_data->clear_sr, reg);
+ }
+
+ /* see if we need to reload the config registers */
+ if ((read_SSCR0(reg) != cr0)
+ || (read_SSCR1(reg) & SSCR1_CHANGE_MASK) !=
+ (cr1 & SSCR1_CHANGE_MASK)) {
+
+ /* stop the SSP, and update the other bits */
+ write_SSCR0(cr0 & ~SSCR0_SSE, reg);
+ if (drv_data->ssp_type != PXA25x_SSP)
+ write_SSTO(chip->timeout, reg);
+ /* first set CR1 without interrupt and service enables */
+ write_SSCR1(cr1 & SSCR1_CHANGE_MASK, reg);
+ /* restart the SSP */
+ write_SSCR0(cr0, reg);
+
+ } else {
+ if (drv_data->ssp_type != PXA25x_SSP)
+ write_SSTO(chip->timeout, reg);
+ }
+
+ cs_assert(drv_data);
+
+ /* after chip select, release the data by enabling service
+ * requests and interrupts, without changing any mode bits */
+ write_SSCR1(cr1, reg);
+}
+
+static void pump_messages(struct work_struct *work)
+{
+ struct driver_data *drv_data =
+ container_of(work, struct driver_data, pump_messages);
+ 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);
+
+ /* 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);
+
+ /* prepare to setup the SSP, in pump_transfers, using the per
+ * chip configuration */
+ drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
+
+ /* Mark as busy and launch transfers */
+ tasklet_schedule(&drv_data->pump_transfers);
+
+ drv_data->busy = 1;
+ spin_unlock_irqrestore(&drv_data->lock, flags);
+}
+
+static int transfer(struct spi_device *spi, struct spi_message *msg)
+{
+ struct driver_data *drv_data = spi_master_get_devdata(spi->master);
+ unsigned long flags;
+
+ spin_lock_irqsave(&drv_data->lock, flags);
+
+ if (drv_data->run == QUEUE_STOPPED) {
+ spin_unlock_irqrestore(&drv_data->lock, flags);
+ return -ESHUTDOWN;
+ }
+
+ msg->actual_length = 0;
+ msg->status = -EINPROGRESS;
+ msg->state = START_STATE;
+
+ list_add_tail(&msg->queue, &drv_data->queue);
+
+ if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
+ queue_work(drv_data->workqueue, &drv_data->pump_messages);
+
+ spin_unlock_irqrestore(&drv_data->lock, flags);
+
+ return 0;
+}
+
+static int setup_cs(struct spi_device *spi, struct chip_data *chip,
+ struct pxa2xx_spi_chip *chip_info)
+{
+ int err = 0;
+
+ if (chip == NULL || chip_info == NULL)
+ return 0;
+
+ /* NOTE: setup() can be called multiple times, possibly with
+ * different chip_info, release previously requested GPIO
+ */
+ if (gpio_is_valid(chip->gpio_cs))
+ gpio_free(chip->gpio_cs);
+
+ /* If (*cs_control) is provided, ignore GPIO chip select */
+ if (chip_info->cs_control) {
+ chip->cs_control = chip_info->cs_control;
+ return 0;
+ }
+
+ if (gpio_is_valid(chip_info->gpio_cs)) {
+ err = gpio_request(chip_info->gpio_cs, "SPI_CS");
+ if (err) {
+ dev_err(&spi->dev, "failed to request chip select "
+ "GPIO%d\n", chip_info->gpio_cs);
+ return err;
+ }
+
+ chip->gpio_cs = chip_info->gpio_cs;
+ chip->gpio_cs_inverted = spi->mode & SPI_CS_HIGH;
+
+ err = gpio_direction_output(chip->gpio_cs,
+ !chip->gpio_cs_inverted);
+ }
+
+ return err;
+}
+
+static int setup(struct spi_device *spi)
+{
+ struct pxa2xx_spi_chip *chip_info = NULL;
+ struct chip_data *chip;
+ struct driver_data *drv_data = spi_master_get_devdata(spi->master);
+ struct ssp_device *ssp = drv_data->ssp;
+ unsigned int clk_div;
+ uint tx_thres = TX_THRESH_DFLT;
+ uint rx_thres = RX_THRESH_DFLT;
+
+ if (drv_data->ssp_type != PXA25x_SSP
+ && (spi->bits_per_word < 4 || spi->bits_per_word > 32)) {
+ dev_err(&spi->dev, "failed setup: ssp_type=%d, bits/wrd=%d "
+ "b/w not 4-32 for type non-PXA25x_SSP\n",
+ drv_data->ssp_type, spi->bits_per_word);
+ return -EINVAL;
+ }
+ else if (drv_data->ssp_type == PXA25x_SSP
+ && (spi->bits_per_word < 4
+ || spi->bits_per_word > 16)) {
+ dev_err(&spi->dev, "failed setup: ssp_type=%d, bits/wrd=%d "
+ "b/w not 4-16 for type PXA25x_SSP\n",
+ drv_data->ssp_type, spi->bits_per_word);
+ return -EINVAL;
+ }
+
+ /* Only alloc on first setup */
+ chip = spi_get_ctldata(spi);
+ if (!chip) {
+ chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
+ if (!chip) {
+ dev_err(&spi->dev,
+ "failed setup: can't allocate chip data\n");
+ return -ENOMEM;
+ }
+
+ chip->gpio_cs = -1;
+ chip->enable_dma = 0;
+ chip->timeout = TIMOUT_DFLT;
+ chip->dma_burst_size = drv_data->master_info->enable_dma ?
+ DCMD_BURST8 : 0;
+ }
+
+ /* protocol drivers may change the chip settings, so...
+ * if chip_info exists, use it */
+ chip_info = spi->controller_data;
+
+ /* chip_info isn't always needed */
+ chip->cr1 = 0;
+ if (chip_info) {
+ if (chip_info->timeout)
+ chip->timeout = chip_info->timeout;
+ if (chip_info->tx_threshold)
+ tx_thres = chip_info->tx_threshold;
+ if (chip_info->rx_threshold)
+ rx_thres = chip_info->rx_threshold;
+ chip->enable_dma = drv_data->master_info->enable_dma;
+ chip->dma_threshold = 0;
+ if (chip_info->enable_loopback)
+ chip->cr1 = SSCR1_LBM;
+ }
+
+ chip->threshold = (SSCR1_RxTresh(rx_thres) & SSCR1_RFT) |
+ (SSCR1_TxTresh(tx_thres) & SSCR1_TFT);
+
+ /* set dma burst and threshold outside of chip_info path so that if
+ * chip_info goes away after setting chip->enable_dma, the
+ * burst and threshold can still respond to changes in bits_per_word */
+ if (chip->enable_dma) {
+ /* set up legal burst and threshold for dma */
+ if (set_dma_burst_and_threshold(chip, spi, spi->bits_per_word,
+ &chip->dma_burst_size,
+ &chip->dma_threshold)) {
+ dev_warn(&spi->dev, "in setup: DMA burst size reduced "
+ "to match bits_per_word\n");
+ }
+ }
+
+ clk_div = ssp_get_clk_div(ssp, spi->max_speed_hz);
+ chip->speed_hz = spi->max_speed_hz;
+
+ chip->cr0 = clk_div
+ | SSCR0_Motorola
+ | SSCR0_DataSize(spi->bits_per_word > 16 ?
+ spi->bits_per_word - 16 : spi->bits_per_word)
+ | SSCR0_SSE
+ | (spi->bits_per_word > 16 ? SSCR0_EDSS : 0);
+ chip->cr1 &= ~(SSCR1_SPO | SSCR1_SPH);
+ chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) ? SSCR1_SPH : 0)
+ | (((spi->mode & SPI_CPOL) != 0) ? SSCR1_SPO : 0);
+
+ /* NOTE: PXA25x_SSP _could_ use external clocking ... */
+ if (drv_data->ssp_type != PXA25x_SSP)
+ dev_dbg(&spi->dev, "%ld Hz actual, %s\n",
+ clk_get_rate(ssp->clk)
+ / (1 + ((chip->cr0 & SSCR0_SCR(0xfff)) >> 8)),
+ chip->enable_dma ? "DMA" : "PIO");
+ else
+ dev_dbg(&spi->dev, "%ld Hz actual, %s\n",
+ clk_get_rate(ssp->clk) / 2
+ / (1 + ((chip->cr0 & SSCR0_SCR(0x0ff)) >> 8)),
+ chip->enable_dma ? "DMA" : "PIO");
+
+ if (spi->bits_per_word <= 8) {
+ chip->n_bytes = 1;
+ chip->dma_width = DCMD_WIDTH1;
+ chip->read = u8_reader;
+ chip->write = u8_writer;
+ } else if (spi->bits_per_word <= 16) {
+ chip->n_bytes = 2;
+ chip->dma_width = DCMD_WIDTH2;
+ chip->read = u16_reader;
+ chip->write = u16_writer;
+ } else if (spi->bits_per_word <= 32) {
+ chip->cr0 |= SSCR0_EDSS;
+ chip->n_bytes = 4;
+ chip->dma_width = DCMD_WIDTH4;
+ chip->read = u32_reader;
+ chip->write = u32_writer;
+ } else {
+ dev_err(&spi->dev, "invalid wordsize\n");
+ return -ENODEV;
+ }
+ chip->bits_per_word = spi->bits_per_word;
+
+ spi_set_ctldata(spi, chip);
+
+ return setup_cs(spi, chip, chip_info);
+}
+
+static void cleanup(struct spi_device *spi)
+{
+ struct chip_data *chip = spi_get_ctldata(spi);
+
+ if (!chip)
+ return;
+
+ if (gpio_is_valid(chip->gpio_cs))
+ gpio_free(chip->gpio_cs);
+
+ kfree(chip);
+}
+
+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->pump_messages, 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->pump_messages);
+
+ 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);
+ /* we are unloading the module or failing to load (only two calls
+ * to this routine), and neither call can handle a return value.
+ * However, destroy_workqueue calls flush_workqueue, and that will
+ * block until all work is done. If the reason that stop_queue
+ * timed out is that the work will never finish, then it does no
+ * good to call destroy_workqueue, so return anyway. */
+ if (status != 0)
+ return status;
+
+ destroy_workqueue(drv_data->workqueue);
+
+ return 0;
+}
+
+static int __init pxa2xx_spi_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct pxa2xx_spi_master *platform_info;
+ struct spi_master *master;
+ struct driver_data *drv_data;
+ struct ssp_device *ssp;
+ int status;
+
+ platform_info = dev->platform_data;
+
+ ssp = pxa_ssp_request(pdev->id, pdev->name);
+ if (ssp == NULL) {
+ dev_err(&pdev->dev, "failed to request SSP%d\n", pdev->id);
+ return -ENODEV;
+ }
+
+ /* Allocate master with space for drv_data and null dma buffer */
+ master = spi_alloc_master(dev, sizeof(struct driver_data) + 16);
+ if (!master) {
+ dev_err(&pdev->dev, "cannot alloc spi_master\n");
+ pxa_ssp_free(ssp);
+ return -ENOMEM;
+ }
+ drv_data = spi_master_get_devdata(master);
+ drv_data->master = master;
+ drv_data->master_info = platform_info;
+ drv_data->pdev = pdev;
+ drv_data->ssp = ssp;
+
+ /* 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->ssp_type = ssp->type;
+ drv_data->null_dma_buf = (u32 *)ALIGN((u32)(drv_data +
+ sizeof(struct driver_data)), 8);
+
+ drv_data->ioaddr = ssp->mmio_base;
+ drv_data->ssdr_physical = ssp->phys_base + SSDR;
+ if (ssp->type == PXA25x_SSP) {
+ drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE;
+ drv_data->dma_cr1 = 0;
+ drv_data->clear_sr = SSSR_ROR;
+ drv_data->mask_sr = SSSR_RFS | SSSR_TFS | SSSR_ROR;
+ } else {
+ drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE;
+ drv_data->dma_cr1 = SSCR1_TSRE | SSCR1_RSRE | SSCR1_TINTE;
+ drv_data->clear_sr = SSSR_ROR | SSSR_TINT;
+ drv_data->mask_sr = SSSR_TINT | SSSR_RFS | SSSR_TFS | SSSR_ROR;
+ }
+
+ status = request_irq(ssp->irq, ssp_int, 0, dev_name(dev), drv_data);
+ if (status < 0) {
+ dev_err(&pdev->dev, "cannot get IRQ %d\n", ssp->irq);
+ goto out_error_master_alloc;
+ }
+
+ /* Setup DMA if requested */
+ drv_data->tx_channel = -1;
+ drv_data->rx_channel = -1;
+ if (platform_info->enable_dma) {
+
+ /* Get two DMA channels (rx and tx) */
+ drv_data->rx_channel = pxa_request_dma("pxa2xx_spi_ssp_rx",
+ DMA_PRIO_HIGH,
+ dma_handler,
+ drv_data);
+ if (drv_data->rx_channel < 0) {
+ dev_err(dev, "problem (%d) requesting rx channel\n",
+ drv_data->rx_channel);
+ status = -ENODEV;
+ goto out_error_irq_alloc;
+ }
+ drv_data->tx_channel = pxa_request_dma("pxa2xx_spi_ssp_tx",
+ DMA_PRIO_MEDIUM,
+ dma_handler,
+ drv_data);
+ if (drv_data->tx_channel < 0) {
+ dev_err(dev, "problem (%d) requesting tx channel\n",
+ drv_data->tx_channel);
+ status = -ENODEV;
+ goto out_error_dma_alloc;
+ }
+
+ DRCMR(ssp->drcmr_rx) = DRCMR_MAPVLD | drv_data->rx_channel;
+ DRCMR(ssp->drcmr_tx) = DRCMR_MAPVLD | drv_data->tx_channel;
+ }
+
+ /* Enable SOC clock */
+ clk_enable(ssp->clk);
+
+ /* Load default SSP configuration */
+ write_SSCR0(0, drv_data->ioaddr);
+ write_SSCR1(SSCR1_RxTresh(RX_THRESH_DFLT) |
+ SSCR1_TxTresh(TX_THRESH_DFLT),
+ drv_data->ioaddr);
+ write_SSCR0(SSCR0_SCR(2)
+ | SSCR0_Motorola
+ | SSCR0_DataSize(8),
+ drv_data->ioaddr);
+ if (drv_data->ssp_type != PXA25x_SSP)
+ write_SSTO(0, drv_data->ioaddr);
+ write_SSPSP(0, drv_data->ioaddr);
+
+ /* Initial and start queue */
+ status = init_queue(drv_data);
+ if (status != 0) {
+ dev_err(&pdev->dev, "problem initializing queue\n");
+ goto out_error_clock_enabled;
+ }
+ status = start_queue(drv_data);
+ if (status != 0) {
+ dev_err(&pdev->dev, "problem starting queue\n");
+ goto out_error_clock_enabled;
+ }
+
+ /* Register with the SPI framework */
+ platform_set_drvdata(pdev, drv_data);
+ status = spi_register_master(master);
+ if (status != 0) {
+ dev_err(&pdev->dev, "problem registering spi master\n");
+ goto out_error_queue_alloc;
+ }
+
+ return status;
+
+out_error_queue_alloc:
+ destroy_queue(drv_data);
+
+out_error_clock_enabled:
+ clk_disable(ssp->clk);
+
+out_error_dma_alloc:
+ if (drv_data->tx_channel != -1)
+ pxa_free_dma(drv_data->tx_channel);
+ if (drv_data->rx_channel != -1)
+ pxa_free_dma(drv_data->rx_channel);
+
+out_error_irq_alloc:
+ free_irq(ssp->irq, drv_data);
+
+out_error_master_alloc:
+ spi_master_put(master);
+ pxa_ssp_free(ssp);
+ return status;
+}
+
+static int pxa2xx_spi_remove(struct platform_device *pdev)
+{
+ struct driver_data *drv_data = platform_get_drvdata(pdev);
+ struct ssp_device *ssp;
+ int status = 0;
+
+ if (!drv_data)
+ return 0;
+ ssp = drv_data->ssp;
+
+ /* Remove the queue */
+ status = destroy_queue(drv_data);
+ if (status != 0)
+ /* the kernel does not check the return status of this
+ * this routine (mod->exit, within the kernel). Therefore
+ * nothing is gained by returning from here, the module is
+ * going away regardless, and we should not leave any more
+ * resources allocated than necessary. We cannot free the
+ * message memory in drv_data->queue, but we can release the
+ * resources below. I think the kernel should honor -EBUSY
+ * returns but... */
+ dev_err(&pdev->dev, "pxa2xx_spi_remove: workqueue will not "
+ "complete, message memory not freed\n");
+
+ /* Disable the SSP at the peripheral and SOC level */
+ write_SSCR0(0, drv_data->ioaddr);
+ clk_disable(ssp->clk);
+
+ /* Release DMA */
+ if (drv_data->master_info->enable_dma) {
+ DRCMR(ssp->drcmr_rx) = 0;
+ DRCMR(ssp->drcmr_tx) = 0;
+ pxa_free_dma(drv_data->tx_channel);
+ pxa_free_dma(drv_data->rx_channel);
+ }
+
+ /* Release IRQ */
+ free_irq(ssp->irq, drv_data);
+
+ /* Release SSP */
+ pxa_ssp_free(ssp);
+
+ /* Disconnect from the SPI framework */
+ spi_unregister_master(drv_data->master);
+
+ /* Prevent double remove */
+ platform_set_drvdata(pdev, NULL);
+
+ return 0;
+}
+
+static void pxa2xx_spi_shutdown(struct platform_device *pdev)
+{
+ int status = 0;
+
+ if ((status = pxa2xx_spi_remove(pdev)) != 0)
+ dev_err(&pdev->dev, "shutdown failed with %d\n", status);
+}
+
+#ifdef CONFIG_PM
+static int pxa2xx_spi_suspend(struct device *dev)
+{
+ struct driver_data *drv_data = dev_get_drvdata(dev);
+ struct ssp_device *ssp = drv_data->ssp;
+ int status = 0;
+
+ status = stop_queue(drv_data);
+ if (status != 0)
+ return status;
+ write_SSCR0(0, drv_data->ioaddr);
+ clk_disable(ssp->clk);
+
+ return 0;
+}
+
+static int pxa2xx_spi_resume(struct device *dev)
+{
+ struct driver_data *drv_data = dev_get_drvdata(dev);
+ struct ssp_device *ssp = drv_data->ssp;
+ int status = 0;
+
+ if (drv_data->rx_channel != -1)
+ DRCMR(drv_data->ssp->drcmr_rx) =
+ DRCMR_MAPVLD | drv_data->rx_channel;
+ if (drv_data->tx_channel != -1)
+ DRCMR(drv_data->ssp->drcmr_tx) =
+ DRCMR_MAPVLD | drv_data->tx_channel;
+
+ /* Enable the SSP clock */
+ clk_enable(ssp->clk);
+
+ /* Start the queue running */
+ status = start_queue(drv_data);
+ if (status != 0) {
+ dev_err(dev, "problem starting queue (%d)\n", status);
+ return status;
+ }
+
+ return 0;
+}
+
+static const struct dev_pm_ops pxa2xx_spi_pm_ops = {
+ .suspend = pxa2xx_spi_suspend,
+ .resume = pxa2xx_spi_resume,
+};
+#endif
+
+static struct platform_driver driver = {
+ .driver = {
+ .name = "pxa2xx-spi",
+ .owner = THIS_MODULE,
+#ifdef CONFIG_PM
+ .pm = &pxa2xx_spi_pm_ops,
+#endif
+ },
+ .remove = pxa2xx_spi_remove,
+ .shutdown = pxa2xx_spi_shutdown,
+};
+
+static int __init pxa2xx_spi_init(void)
+{
+ return platform_driver_probe(&driver, pxa2xx_spi_probe);
+}
+subsys_initcall(pxa2xx_spi_init);
+
+static void __exit pxa2xx_spi_exit(void)
+{
+ platform_driver_unregister(&driver);
+}
+module_exit(pxa2xx_spi_exit);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-25 04:32:58 +0000