diff options
Diffstat (limited to 'drivers/spi/spi-pxa2xx.c')
| -rw-r--r-- | drivers/spi/spi-pxa2xx.c | 1816 |
1 files changed, 1816 insertions, 0 deletions
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c new file mode 100644 index 000000000000..dc25bee8d33f --- /dev/null +++ b/drivers/spi/spi-pxa2xx.c @@ -0,0 +1,1816 @@ +/* + * 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/spi/pxa2xx_spi.h> +#include <linux/dma-mapping.h> +#include <linux/spi/spi.h> +#include <linux/workqueue.h> +#include <linux/delay.h> +#include <linux/gpio.h> +#include <linux/slab.h> + +#include <asm/io.h> +#include <asm/irq.h> +#include <asm/delay.h> + + +MODULE_AUTHOR("Stephen Street"); +MODULE_DESCRIPTION("PXA2xx SSP SPI Controller"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:pxa2xx-spi"); + +#define MAX_BUSES 3 + +#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; + union { + int gpio_cs; + unsigned int frm; + }; + 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 (drv_data->ssp_type == CE4100_SSP) { + write_SSSR(drv_data->cur_chip->frm, drv_data->ioaddr); + return; + } + + 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 (drv_data->ssp_type == CE4100_SSP) + return; + + 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 void write_SSSR_CS(struct driver_data *drv_data, u32 val) +{ + void __iomem *reg = drv_data->ioaddr; + + if (drv_data->ssp_type == CE4100_SSP) + val |= read_SSSR(reg) & SSSR_ALT_FRM_MASK; + + write_SSSR(val, reg); +} + +static int pxa25x_ssp_comp(struct driver_data *drv_data) +{ + if (drv_data->ssp_type == PXA25x_SSP) + return 1; + if (drv_data->ssp_type == CE4100_SSP) + return 1; + return 0; +} + +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_CS(drv_data, SSSR_ROR); + + 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) & SSSR_TFL_MASK) == SSSR_TFL_MASK) + || (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) & SSSR_TFL_MASK) == SSSR_TFL_MASK) + || (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) & SSSR_TFL_MASK) == SSSR_TFL_MASK) + || (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) & SSSR_TFL_MASK) == SSSR_TFL_MASK) + || (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_CS(drv_data, drv_data->clear_sr); + write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg); + if (!pxa25x_ssp_comp(drv_data)) + 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_CS(drv_data, drv_data->clear_sr); + 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 (!pxa25x_ssp_comp(drv_data)) + 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 reset_sccr1(struct driver_data *drv_data) +{ + void __iomem *reg = drv_data->ioaddr; + struct chip_data *chip = drv_data->cur_chip; + u32 sccr1_reg; + + sccr1_reg = read_SSCR1(reg) & ~drv_data->int_cr1; + sccr1_reg &= ~SSCR1_RFT; + sccr1_reg |= chip->threshold; + write_SSCR1(sccr1_reg, reg); +} + +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_CS(drv_data, drv_data->clear_sr); + reset_sccr1(drv_data); + if (!pxa25x_ssp_comp(drv_data)) + 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_CS(drv_data, drv_data->clear_sr); + reset_sccr1(drv_data); + if (!pxa25x_ssp_comp(drv_data)) + write_SSTO(0, reg); + + /* Update total byte transferred 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) { + u32 bytes_left; + u32 sccr1_reg; + + sccr1_reg = read_SSCR1(reg); + sccr1_reg &= ~SSCR1_TIE; + + /* + * PXA25x_SSP has no timeout, set up rx threshould for the + * remaining RX bytes. + */ + if (pxa25x_ssp_comp(drv_data)) { + + sccr1_reg &= ~SSCR1_RFT; + + bytes_left = drv_data->rx_end - drv_data->rx; + switch (drv_data->n_bytes) { + case 4: + bytes_left >>= 1; + case 2: + bytes_left >>= 1; + } + + if (bytes_left > RX_THRESH_DFLT) + bytes_left = RX_THRESH_DFLT; + + sccr1_reg |= SSCR1_RxTresh(bytes_left); + } + write_SSCR1(sccr1_reg, reg); + } + + /* 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; + u32 sccr1_reg = read_SSCR1(reg); + u32 mask = drv_data->mask_sr; + u32 status; + + status = read_SSSR(reg); + + /* Ignore possible writes if we don't need to write */ + if (!(sccr1_reg & SSCR1_TIE)) + mask &= ~SSSR_TFS; + + if (!(status & mask)) + return IRQ_NONE; + + if (!drv_data->cur_msg) { + + write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg); + write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg); + if (!pxa25x_ssp_comp(drv_data)) + write_SSTO(0, reg); + write_SSSR_CS(drv_data, drv_data->clear_sr); + + 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 || ssp->type == CE4100_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_CS(drv_data, drv_data->clear_sr); + } + + /* 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 (!pxa25x_ssp_comp(drv_data)) + 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 (!pxa25x_ssp_comp(drv_data)) + 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 (!pxa25x_ssp_comp(drv_data) + && (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 (pxa25x_ssp_comp(drv_data) + && (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; + } + + if (drv_data->ssp_type == CE4100_SSP) { + if (spi->chip_select > 4) { + dev_err(&spi->dev, "failed setup: " + "cs number must not be > 4.\n"); + kfree(chip); + return -EINVAL; + } + + chip->frm = spi->chip_select; + } else + 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 (!pxa25x_ssp_comp(drv_data)) + 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); + + if (drv_data->ssp_type == CE4100_SSP) + return 0; + + return setup_cs(spi, chip, chip_info); +} + +static void cleanup(struct spi_device *spi) +{ + struct chip_data *chip = spi_get_ctldata(spi); + struct driver_data *drv_data = spi_master_get_devdata(spi->master); + + if (!chip) + return; + + if (drv_data->ssp_type != CE4100_SSP && gpio_is_valid(chip->gpio_cs)) + gpio_free(chip->gpio_cs); + + kfree(chip); +} + +static int __devinit 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 __devinit 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; + + master->dev.parent = &pdev->dev; + master->dev.of_node = pdev->dev.of_node; + /* 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 (pxa25x_ssp_comp(drv_data)) { + 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, IRQF_SHARED, 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 (!pxa25x_ssp_comp(drv_data)) + 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 + }, + .probe = pxa2xx_spi_probe, + .remove = pxa2xx_spi_remove, + .shutdown = pxa2xx_spi_shutdown, +}; + +static int __init pxa2xx_spi_init(void) +{ + return platform_driver_register(&driver); +} +subsys_initcall(pxa2xx_spi_init); + +static void __exit pxa2xx_spi_exit(void) +{ + platform_driver_unregister(&driver); +} +module_exit(pxa2xx_spi_exit); |