diff options
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/pxa2xx_spi.c | 733 |
1 files changed, 440 insertions, 293 deletions
diff --git a/drivers/spi/pxa2xx_spi.c b/drivers/spi/pxa2xx_spi.c index 494d9b85648..6ed3f1da929 100644 --- a/drivers/spi/pxa2xx_spi.c +++ b/drivers/spi/pxa2xx_spi.c @@ -49,6 +49,14 @@ MODULE_LICENSE("GPL"); #define RESET_DMA_CHANNEL (DCSR_NODESC | DMA_INT_MASK) #define IS_DMA_ALIGNED(x) (((u32)(x)&0x07)==0) +/* for testing SSCR1 changes that require SSP restart, basically + * everything except the service and interrupt enables */ +#define SSCR1_CHANGE_MASK (SSCR1_TTELP | SSCR1_TTE | SSCR1_EBCEI | SSCR1_SCFR \ + | SSCR1_ECRA | SSCR1_ECRB | SSCR1_SCLKDIR \ + | SSCR1_RWOT | SSCR1_TRAIL | SSCR1_PINTE \ + | SSCR1_STRF | SSCR1_EFWR |SSCR1_RFT \ + | SSCR1_TFT | SSCR1_SPH | SSCR1_SPO | SSCR1_LBM) + #define DEFINE_SSP_REG(reg, off) \ static inline u32 read_##reg(void *p) { return __raw_readl(p + (off)); } \ static inline void write_##reg(u32 v, void *p) { __raw_writel(v, p + (off)); } @@ -123,8 +131,8 @@ struct driver_data { u8 n_bytes; u32 dma_width; int cs_change; - void (*write)(struct driver_data *drv_data); - void (*read)(struct driver_data *drv_data); + 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); }; @@ -132,7 +140,6 @@ struct driver_data { struct chip_data { u32 cr0; u32 cr1; - u32 to; u32 psp; u32 timeout; u8 n_bytes; @@ -143,8 +150,8 @@ struct chip_data { u8 enable_dma; u8 bits_per_word; u32 speed_hz; - void (*write)(struct driver_data *drv_data); - void (*read)(struct driver_data *drv_data); + int (*write)(struct driver_data *drv_data); + int (*read)(struct driver_data *drv_data); void (*cs_control)(u32 command); }; @@ -166,114 +173,118 @@ static int flush(struct driver_data *drv_data) return limit; } -static void restore_state(struct driver_data *drv_data) -{ - void *reg = drv_data->ioaddr; - - /* Clear status and disable clock */ - write_SSSR(drv_data->clear_sr, reg); - write_SSCR0(drv_data->cur_chip->cr0 & ~SSCR0_SSE, reg); - - /* Load the registers */ - write_SSCR1(drv_data->cur_chip->cr1, reg); - write_SSCR0(drv_data->cur_chip->cr0, reg); - if (drv_data->ssp_type != PXA25x_SSP) { - write_SSTO(0, reg); - write_SSPSP(drv_data->cur_chip->psp, reg); - } -} - static void null_cs_control(u32 command) { } -static void null_writer(struct driver_data *drv_data) +static int null_writer(struct driver_data *drv_data) { void *reg = drv_data->ioaddr; u8 n_bytes = drv_data->n_bytes; - while ((read_SSSR(reg) & SSSR_TNF) - && (drv_data->tx < drv_data->tx_end)) { - write_SSDR(0, reg); - drv_data->tx += 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 void null_reader(struct driver_data *drv_data) +static int null_reader(struct driver_data *drv_data) { void *reg = drv_data->ioaddr; u8 n_bytes = drv_data->n_bytes; while ((read_SSSR(reg) & SSSR_RNE) - && (drv_data->rx < drv_data->rx_end)) { + && (drv_data->rx < drv_data->rx_end)) { read_SSDR(reg); drv_data->rx += n_bytes; } + + return drv_data->rx == drv_data->rx_end; } -static void u8_writer(struct driver_data *drv_data) +static int u8_writer(struct driver_data *drv_data) { void *reg = drv_data->ioaddr; - while ((read_SSSR(reg) & SSSR_TNF) - && (drv_data->tx < drv_data->tx_end)) { - write_SSDR(*(u8 *)(drv_data->tx), reg); - ++drv_data->tx; - } + 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 void u8_reader(struct driver_data *drv_data) +static int u8_reader(struct driver_data *drv_data) { void *reg = drv_data->ioaddr; while ((read_SSSR(reg) & SSSR_RNE) - && (drv_data->rx < drv_data->rx_end)) { + && (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 void u16_writer(struct driver_data *drv_data) +static int u16_writer(struct driver_data *drv_data) { void *reg = drv_data->ioaddr; - while ((read_SSSR(reg) & SSSR_TNF) - && (drv_data->tx < drv_data->tx_end)) { - write_SSDR(*(u16 *)(drv_data->tx), reg); - drv_data->tx += 2; - } + 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 void u16_reader(struct driver_data *drv_data) +static int u16_reader(struct driver_data *drv_data) { void *reg = drv_data->ioaddr; while ((read_SSSR(reg) & SSSR_RNE) - && (drv_data->rx < drv_data->rx_end)) { + && (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 void u32_writer(struct driver_data *drv_data) + +static int u32_writer(struct driver_data *drv_data) { void *reg = drv_data->ioaddr; - while ((read_SSSR(reg) & SSSR_TNF) - && (drv_data->tx < drv_data->tx_end)) { - write_SSDR(*(u32 *)(drv_data->tx), reg); - drv_data->tx += 4; - } + 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 void u32_reader(struct driver_data *drv_data) +static int u32_reader(struct driver_data *drv_data) { void *reg = drv_data->ioaddr; while ((read_SSSR(reg) & SSSR_RNE) - && (drv_data->rx < drv_data->rx_end)) { + && (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) @@ -409,166 +420,134 @@ static int wait_dma_channel_stop(int channel) return limit; } -static void dma_handler(int channel, void *data) +void dma_error_stop(struct driver_data *drv_data, const char *msg) { - struct driver_data *drv_data = data; - struct spi_message *msg = drv_data->cur_msg; void *reg = drv_data->ioaddr; - u32 irq_status = DCSR(channel) & DMA_INT_MASK; - u32 trailing_sssr = 0; - if (irq_status & DCSR_BUSERR) { + /* 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); - /* Disable interrupts, clear status and reset DMA */ - write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg); - write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg); - if (drv_data->ssp_type != PXA25x_SSP) - write_SSTO(0, reg); - write_SSSR(drv_data->clear_sr, reg); - DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL; - DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL; + unmap_dma_buffers(drv_data); - if (flush(drv_data) == 0) - dev_err(&drv_data->pdev->dev, - "dma_handler: flush fail\n"); + dev_err(&drv_data->pdev->dev, "%s\n", msg); - unmap_dma_buffers(drv_data); + drv_data->cur_msg->state = ERROR_STATE; + tasklet_schedule(&drv_data->pump_transfers); +} + +static void dma_transfer_complete(struct driver_data *drv_data) +{ + void *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); + + /* Release chip select if requested, transfer delays are + * handled in pump_transfers */ + if (drv_data->cs_change) + drv_data->cs_control(PXA2XX_CS_DEASSERT); + + /* 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) - dev_err(&drv_data->pdev->dev, - "dma_handler: bad bus address on " - "tx channel %d, source %x target = %x\n", - channel, DSADR(channel), DTADR(channel)); + dma_error_stop(drv_data, + "dma_handler: " + "bad bus address on tx channel"); else - dev_err(&drv_data->pdev->dev, - "dma_handler: bad bus address on " - "rx channel %d, source %x target = %x\n", - channel, DSADR(channel), DTADR(channel)); - - msg->state = ERROR_STATE; - tasklet_schedule(&drv_data->pump_transfers); + 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 ((drv_data->ssp_type == PXA25x_SSP) - && (channel == drv_data->tx_channel) - && (irq_status & DCSR_ENDINTR)) { + 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"); - /* 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"); - - unmap_dma_buffers(drv_data); - - /* Read trailing bytes */ - /* Calculate number of trailing bytes, read them */ - trailing_sssr = read_SSSR(reg); - if ((trailing_sssr & 0xf008) != 0xf000) { - drv_data->rx = drv_data->rx_end - - (((trailing_sssr >> 12) & 0x0f) + 1); - drv_data->read(drv_data); - } - msg->actual_length += drv_data->len; - - /* Release chip select if requested, transfer delays are - * handled in pump_transfers */ - if (drv_data->cs_change) - drv_data->cs_control(PXA2XX_CS_DEASSERT); - - /* Move to next transfer */ - msg->state = next_transfer(drv_data); - - /* Schedule transfer tasklet */ - tasklet_schedule(&drv_data->pump_transfers); + /* finish this transfer, start the next */ + dma_transfer_complete(drv_data); } } static irqreturn_t dma_transfer(struct driver_data *drv_data) { u32 irq_status; - u32 trailing_sssr = 0; - struct spi_message *msg = drv_data->cur_msg; void *reg = drv_data->ioaddr; irq_status = read_SSSR(reg) & drv_data->mask_sr; if (irq_status & SSSR_ROR) { - /* Clear and disable interrupts on SSP and DMA channels*/ - write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg); - write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg); - if (drv_data->ssp_type != PXA25x_SSP) - write_SSTO(0, reg); - write_SSSR(drv_data->clear_sr, reg); - DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL; - DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL; - unmap_dma_buffers(drv_data); - - if (flush(drv_data) == 0) - dev_err(&drv_data->pdev->dev, - "dma_transfer: flush fail\n"); - - dev_warn(&drv_data->pdev->dev, "dma_transfer: fifo overun\n"); - - drv_data->cur_msg->state = ERROR_STATE; - tasklet_schedule(&drv_data->pump_transfers); - + 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) { + 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 interrupts on SSP and DMA channels*/ - write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg); + /* Clear and disable timeout interrupt, do the rest in + * dma_transfer_complete */ if (drv_data->ssp_type != PXA25x_SSP) write_SSTO(0, 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_transfer: 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); - - /* Calculate number of trailing bytes, read them */ - trailing_sssr = read_SSSR(reg); - if ((trailing_sssr & 0xf008) != 0xf000) { - drv_data->rx = drv_data->rx_end - - (((trailing_sssr >> 12) & 0x0f) + 1); - drv_data->read(drv_data); - } - msg->actual_length += drv_data->len; - - /* Release chip select if requested, transfer delays are - * handled in pump_transfers */ - if (drv_data->cs_change) - drv_data->cs_control(PXA2XX_CS_DEASSERT); - - /* Move to next transfer */ - msg->state = next_transfer(drv_data); - - /* Schedule transfer tasklet */ - tasklet_schedule(&drv_data->pump_transfers); + /* finish this transfer, start the next */ + dma_transfer_complete(drv_data); return IRQ_HANDLED; } @@ -577,89 +556,103 @@ static irqreturn_t dma_transfer(struct driver_data *drv_data) return IRQ_NONE; } -static irqreturn_t interrupt_transfer(struct driver_data *drv_data) +static void int_error_stop(struct driver_data *drv_data, const char* msg) { - struct spi_message *msg = drv_data->cur_msg; void *reg = drv_data->ioaddr; - unsigned long limit = loops_per_jiffy << 1; - u32 irq_status; - u32 irq_mask = (read_SSCR1(reg) & SSCR1_TIE) ? - drv_data->mask_sr : drv_data->mask_sr & ~SSSR_TFS; - - while ((irq_status = read_SSSR(reg) & irq_mask)) { - - if (irq_status & SSSR_ROR) { - /* Clear and disable interrupts */ - 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); + /* 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); - if (flush(drv_data) == 0) - dev_err(&drv_data->pdev->dev, - "interrupt_transfer: flush fail\n"); + dev_err(&drv_data->pdev->dev, "%s\n", msg); - /* Stop the SSP */ + drv_data->cur_msg->state = ERROR_STATE; + tasklet_schedule(&drv_data->pump_transfers); +} - dev_warn(&drv_data->pdev->dev, - "interrupt_transfer: fifo overun\n"); +static void int_transfer_complete(struct driver_data *drv_data) +{ + void *reg = drv_data->ioaddr; - msg->state = ERROR_STATE; - tasklet_schedule(&drv_data->pump_transfers); + /* 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); - return IRQ_HANDLED; - } + /* 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); - /* Look for false positive timeout */ - if ((irq_status & SSSR_TINT) - && (drv_data->rx < drv_data->rx_end)) - write_SSSR(SSSR_TINT, reg); + /* Release chip select if requested, transfer delays are + * handled in pump_transfers */ + if (drv_data->cs_change) + drv_data->cs_control(PXA2XX_CS_DEASSERT); - /* Pump data */ - drv_data->read(drv_data); - drv_data->write(drv_data); + /* Move to next transfer */ + drv_data->cur_msg->state = next_transfer(drv_data); - if (drv_data->tx == drv_data->tx_end) { - /* Disable tx interrupt */ - write_SSCR1(read_SSCR1(reg) & ~SSCR1_TIE, reg); - irq_mask = drv_data->mask_sr & ~SSSR_TFS; + /* Schedule transfer tasklet */ + tasklet_schedule(&drv_data->pump_transfers); +} - /* PXA25x_SSP has no timeout, read trailing bytes */ - if (drv_data->ssp_type == PXA25x_SSP) { - while ((read_SSSR(reg) & SSSR_BSY) && limit--) - drv_data->read(drv_data); +static irqreturn_t interrupt_transfer(struct driver_data *drv_data) +{ + void *reg = drv_data->ioaddr; - if (limit == 0) - dev_err(&drv_data->pdev->dev, - "interrupt_transfer: " - "trailing byte read failed\n"); - } - } + u32 irq_mask = (read_SSCR1(reg) & SSCR1_TIE) ? + drv_data->mask_sr : drv_data->mask_sr & ~SSSR_TFS; - if ((irq_status & SSSR_TINT) - || (drv_data->rx == drv_data->rx_end)) { + u32 irq_status = read_SSSR(reg) & irq_mask; - /* Clear timeout */ - 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); + if (irq_status & SSSR_ROR) { + int_error_stop(drv_data, "interrupt_transfer: fifo overrun"); + return IRQ_HANDLED; + } - /* Update total byte transfered */ - msg->actual_length += drv_data->len; + if (irq_status & SSSR_TINT) { + write_SSSR(SSSR_TINT, reg); + if (drv_data->read(drv_data)) { + int_transfer_complete(drv_data); + return IRQ_HANDLED; + } + } - /* Release chip select if requested, transfer delays are - * handled in pump_transfers */ - if (drv_data->cs_change) - drv_data->cs_control(PXA2XX_CS_DEASSERT); + /* 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)); - /* Move to next transfer */ - msg->state = next_transfer(drv_data); + if (drv_data->read(drv_data)) { + int_transfer_complete(drv_data); + return IRQ_HANDLED; + } - /* Schedule transfer tasklet */ - tasklet_schedule(&drv_data->pump_transfers); + 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); } } @@ -681,7 +674,7 @@ static irqreturn_t ssp_int(int irq, void *dev_id) write_SSSR(drv_data->clear_sr, reg); dev_err(&drv_data->pdev->dev, "bad message state " - "in interrupt handler"); + "in interrupt handler\n"); /* Never fail */ return IRQ_HANDLED; @@ -690,6 +683,102 @@ static irqreturn_t ssp_int(int irq, void *dev_id) return drv_data->transfer_handler(drv_data); } +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 void pump_transfers(unsigned long data) { struct driver_data *drv_data = (struct driver_data *)data; @@ -702,6 +791,9 @@ static void pump_transfers(unsigned long data) 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; @@ -731,6 +823,16 @@ static void pump_transfers(unsigned long data) udelay(previous->delay_usecs); } + /* Check transfer length */ + if (transfer->len > 8191) + { + dev_warn(&drv_data->pdev->dev, "pump_transfers: transfer " + "length greater than 8191\n"); + message->status = -EINVAL; + giveback(drv_data); + return; + } + /* 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"); @@ -747,17 +849,15 @@ static void pump_transfers(unsigned long data) drv_data->rx_end = drv_data->rx + transfer->len; drv_data->rx_dma = transfer->rx_dma; drv_data->tx_dma = transfer->tx_dma; - drv_data->len = transfer->len; + drv_data->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; drv_data->cs_change = transfer->cs_change; /* Change speed and bit per word on a per transfer */ + cr0 = chip->cr0; if (transfer->speed_hz || transfer->bits_per_word) { - /* Disable clock */ - write_SSCR0(chip->cr0 & ~SSCR0_SSE, reg); - cr0 = chip->cr0; bits = chip->bits_per_word; speed = chip->speed_hz; @@ -796,15 +896,24 @@ static void pump_transfers(unsigned long data) 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_transfer: " + "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); - - /* Start it back up */ - write_SSCR0(cr0, reg); } message->state = RUNNING_STATE; @@ -823,13 +932,13 @@ static void pump_transfers(unsigned long data) /* No target address increment */ DCMD(drv_data->rx_channel) = DCMD_FLOWSRC | drv_data->dma_width - | chip->dma_burst_size + | dma_burst | drv_data->len; else DCMD(drv_data->rx_channel) = DCMD_INCTRGADDR | DCMD_FLOWSRC | drv_data->dma_width - | chip->dma_burst_size + | dma_burst | drv_data->len; /* Setup tx DMA Channel */ @@ -840,13 +949,13 @@ static void pump_transfers(unsigned long data) /* No source address increment */ DCMD(drv_data->tx_channel) = DCMD_FLOWTRG | drv_data->dma_width - | chip->dma_burst_size + | dma_burst | drv_data->len; else DCMD(drv_data->tx_channel) = DCMD_INCSRCADDR | DCMD_FLOWTRG | drv_data->dma_width - | chip->dma_burst_size + | dma_burst | drv_data->len; /* Enable dma end irqs on SSP to detect end of transfer */ @@ -856,16 +965,11 @@ static void pump_transfers(unsigned long data) /* Fix me, need to handle cs polarity */ drv_data->cs_control(PXA2XX_CS_ASSERT); - /* Go baby, go */ + /* 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; - if (drv_data->ssp_type != PXA25x_SSP) - write_SSTO(chip->timeout, reg); - write_SSCR1(chip->cr1 - | chip->dma_threshold - | drv_data->dma_cr1, - reg); } else { /* Ensure we have the correct interrupt handler */ drv_data->transfer_handler = interrupt_transfer; @@ -873,14 +977,25 @@ static void pump_transfers(unsigned long data) /* Fix me, need to handle cs polarity */ drv_data->cs_control(PXA2XX_CS_ASSERT); - /* Go baby, go */ + /* 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)) { + + write_SSCR0(cr0 & ~SSCR0_SSE, reg); if (drv_data->ssp_type != PXA25x_SSP) write_SSTO(chip->timeout, reg); - write_SSCR1(chip->cr1 - | chip->threshold - | drv_data->int_cr1, - reg); + write_SSCR1(cr1, reg); + write_SSCR0(cr0, reg); + } else { + if (drv_data->ssp_type != PXA25x_SSP) + write_SSTO(chip->timeout, reg); + write_SSCR1(cr1, reg); } } @@ -915,9 +1030,9 @@ static void pump_messages(struct work_struct *work) struct spi_transfer, transfer_list); - /* Setup the SSP using the per chip configuration */ + /* 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); - restore_state(drv_data); /* Mark as busy and launch transfers */ tasklet_schedule(&drv_data->pump_transfers); @@ -963,63 +1078,77 @@ static int setup(struct spi_device *spi) spi->bits_per_word = 8; if (drv_data->ssp_type != PXA25x_SSP - && (spi->bits_per_word < 4 || spi->bits_per_word > 32)) + && (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 (spi->bits_per_word < 4 || spi->bits_per_word > 16) + } + 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 (or use chip_info) on first setup */ + /* Only alloc on first setup */ chip = spi_get_ctldata(spi); - if (chip == NULL) { + if (!chip) { chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL); - if (!chip) + if (!chip) { + dev_err(&spi->dev, + "failed setup: can't allocate chip data\n"); return -ENOMEM; + } chip->cs_control = null_cs_control; chip->enable_dma = 0; - chip->timeout = SSP_TIMEOUT(1000); + chip->timeout = 1000; chip->threshold = SSCR1_RxTresh(1) | SSCR1_TxTresh(1); chip->dma_burst_size = drv_data->master_info->enable_dma ? DCMD_BURST8 : 0; - - chip_info = spi->controller_data; } + /* 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->cs_control) chip->cs_control = chip_info->cs_control; - chip->timeout = SSP_TIMEOUT(chip_info->timeout_microsecs); + chip->timeout = chip_info->timeout; - chip->threshold = SSCR1_RxTresh(chip_info->rx_threshold) - | SSCR1_TxTresh(chip_info->tx_threshold); + chip->threshold = (SSCR1_RxTresh(chip_info->rx_threshold) & + SSCR1_RFT) | + (SSCR1_TxTresh(chip_info->tx_threshold) & + SSCR1_TFT); chip->enable_dma = chip_info->dma_burst_size != 0 && drv_data->master_info->enable_dma; chip->dma_threshold = 0; - if (chip->enable_dma) { - if (chip_info->dma_burst_size <= 8) { - chip->dma_threshold = SSCR1_RxTresh(8) - | SSCR1_TxTresh(8); - chip->dma_burst_size = DCMD_BURST8; - } else if (chip_info->dma_burst_size <= 16) { - chip->dma_threshold = SSCR1_RxTresh(16) - | SSCR1_TxTresh(16); - chip->dma_burst_size = DCMD_BURST16; - } else { - chip->dma_threshold = SSCR1_RxTresh(32) - | SSCR1_TxTresh(32); - chip->dma_burst_size = DCMD_BURST32; - } - } - - if (chip_info->enable_loopback) chip->cr1 = SSCR1_LBM; } + /* 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"); + } + } + if (drv_data->ioaddr == SSP1_VIRT) clk_div = SSP1_SerClkDiv(spi->max_speed_hz); else if (drv_data->ioaddr == SSP2_VIRT) @@ -1027,7 +1156,11 @@ static int setup(struct spi_device *spi) else if (drv_data->ioaddr == SSP3_VIRT) clk_div = SSP3_SerClkDiv(spi->max_speed_hz); else + { + dev_err(&spi->dev, "failed setup: unknown IO address=0x%p\n", + drv_data->ioaddr); return -ENODEV; + } chip->speed_hz = spi->max_speed_hz; chip->cr0 = clk_div @@ -1071,7 +1204,6 @@ static int setup(struct spi_device *spi) chip->write = u32_writer; } else { dev_err(&spi->dev, "invalid wordsize\n"); - kfree(chip); return -ENODEV; } chip->bits_per_word = spi->bits_per_word; @@ -1162,6 +1294,12 @@ 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; @@ -1360,7 +1498,16 @@ static int pxa2xx_spi_remove(struct platform_device *pdev) /* Remove the queue */ status = destroy_queue(drv_data); if (status != 0) - return status; + /* 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); |