#include <linux/spi/spi.h>
#include <linux/workqueue.h>
#include <linux/delay.h>
+#include <linux/clk.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/arch/hardware.h>
#include <asm/arch/pxa-regs.h>
+#include <asm/arch/regs-ssp.h>
+#include <asm/arch/ssp.h>
#include <asm/arch/pxa2xx_spi.h>
MODULE_AUTHOR("Stephen Street");
-MODULE_DESCRIPTION("PXA2xx SSP SPI Contoller");
+MODULE_DESCRIPTION("PXA2xx SSP SPI Controller");
MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:pxa2xx-spi");
#define MAX_BUSES 3
-#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 DMA_INT_MASK (DCSR_ENDINTR | DCSR_STARTINTR | DCSR_BUSERR)
+#define RESET_DMA_CHANNEL (DCSR_NODESC | DMA_INT_MASK)
+#define IS_DMA_ALIGNED(x) (((x) & 0x07) == 0)
+#define MAX_DMA_LEN 8191
-/* 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 \
+/*
+ * 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_RWOT | SSCR1_TRAIL | SSCR1_PINTE \
- | SSCR1_STRF | SSCR1_EFWR |SSCR1_RFT \
- | SSCR1_TFT | SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
+ | 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 *p) { return __raw_readl(p + (off)); } \
/* 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;
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_transfer *transfer = NULL;
struct spi_transfer *previous = NULL;
struct chip_data *chip = NULL;
+ struct ssp_device *ssp = drv_data->ssp;
void *reg = drv_data->ioaddr;
u32 clk_div = 0;
u8 bits = 0;
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;
+ /* 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 %lu 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 (transfer->bits_per_word)
bits = transfer->bits_per_word;
- if (reg == SSP1_VIRT)
- clk_div = SSP1_SerClkDiv(speed);
- else if (reg == SSP2_VIRT)
- clk_div = SSP2_SerClkDiv(speed);
- else if (reg == SSP3_VIRT)
- clk_div = SSP3_SerClkDiv(speed);
+ clk_div = ssp_get_clk_div(ssp, speed);
if (bits <= 8) {
drv_data->n_bytes = 1;
&dma_thresh))
if (printk_ratelimit())
dev_warn(&message->spi->dev,
- "pump_transfer: "
+ "pump_transfers: "
"DMA burst size reduced to "
"match bits_per_word\n");
}
message->state = RUNNING_STATE;
- /* Try to map dma buffer and do a dma transfer if successful */
- if ((drv_data->dma_mapped = map_dma_buffers(drv_data))) {
+ /* 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;
if (drv_data->ssp_type == PXA25x_SSP)
DCMD(drv_data->tx_channel) |= DCMD_ENDIRQEN;
- /* Fix me, need to handle cs polarity */
- drv_data->cs_control(PXA2XX_CS_ASSERT);
-
/* Clear status and start DMA engine */
cr1 = chip->cr1 | dma_thresh | drv_data->dma_cr1;
write_SSSR(drv_data->clear_sr, reg);
/* Ensure we have the correct interrupt handler */
drv_data->transfer_handler = interrupt_transfer;
- /* Fix me, need to handle cs polarity */
- drv_data->cs_control(PXA2XX_CS_ASSERT);
-
/* Clear status */
cr1 = chip->cr1 | chip->threshold | drv_data->int_cr1;
write_SSSR(drv_data->clear_sr, reg);
|| (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);
- write_SSCR1(cr1, 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);
- write_SSCR1(cr1, reg);
}
+
+ /* FIXME, need to handle cs polarity,
+ * this driver uses struct pxa2xx_spi_chip.cs_control to
+ * specify a CS handling function, and it ignores most
+ * struct spi_device.mode[s], including SPI_CS_HIGH */
+ drv_data->cs_control(PXA2XX_CS_ASSERT);
+
+ /* 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 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;
if (!spi->bits_per_word)
}
}
- if (drv_data->ioaddr == SSP1_VIRT)
- clk_div = SSP1_SerClkDiv(spi->max_speed_hz);
- else if (drv_data->ioaddr == SSP2_VIRT)
- clk_div = SSP2_SerClkDiv(spi->max_speed_hz);
- 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;
- }
+ clk_div = ssp_get_clk_div(ssp, spi->max_speed_hz);
chip->speed_hz = spi->max_speed_hz;
chip->cr0 = clk_div
/* NOTE: PXA25x_SSP _could_ use external clocking ... */
if (drv_data->ssp_type != PXA25x_SSP)
- dev_dbg(&spi->dev, "%d bits/word, %d Hz, mode %d\n",
+ dev_dbg(&spi->dev, "%d bits/word, %ld Hz, mode %d\n",
spi->bits_per_word,
- (CLOCK_SPEED_HZ)
+ clk_get_rate(ssp->clk)
/ (1 + ((chip->cr0 & SSCR0_SCR) >> 8)),
spi->mode & 0x3);
else
- dev_dbg(&spi->dev, "%d bits/word, %d Hz, mode %d\n",
+ dev_dbg(&spi->dev, "%d bits/word, %ld Hz, mode %d\n",
spi->bits_per_word,
- (CLOCK_SPEED_HZ/2)
+ clk_get_rate(ssp->clk)
/ (1 + ((chip->cr0 & SSCR0_SCR) >> 8)),
spi->mode & 0x3);
struct pxa2xx_spi_master *platform_info;
struct spi_master *master;
struct driver_data *drv_data = 0;
- struct resource *memory_resource;
- int irq;
+ struct ssp_device *ssp;
int status = 0;
platform_info = dev->platform_data;
- if (platform_info->ssp_type == SSP_UNDEFINED) {
- dev_err(&pdev->dev, "undefined SSP\n");
+ ssp = ssp_request(pdev->id, pdev->name);
+ if (ssp == NULL) {
+ dev_err(&pdev->dev, "failed to request SSP%d\n", pdev->id);
return -ENODEV;
}
master = spi_alloc_master(dev, sizeof(struct driver_data) + 16);
if (!master) {
dev_err(&pdev->dev, "can not alloc spi_master\n");
+ 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->bus_num = pdev->id;
master->num_chipselect = platform_info->num_chipselect;
master->setup = setup;
master->transfer = transfer;
- drv_data->ssp_type = platform_info->ssp_type;
+ drv_data->ssp_type = ssp->type;
drv_data->null_dma_buf = (u32 *)ALIGN((u32)(drv_data +
sizeof(struct driver_data)), 8);
- /* Setup register addresses */
- memory_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!memory_resource) {
- dev_err(&pdev->dev, "memory resources not defined\n");
- status = -ENODEV;
- goto out_error_master_alloc;
- }
-
- drv_data->ioaddr = (void *)io_p2v((unsigned long)(memory_resource->start));
- drv_data->ssdr_physical = memory_resource->start + 0x00000010;
- if (platform_info->ssp_type == PXA25x_SSP) {
+ 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_TINT | SSSR_RFS | SSSR_TFS | SSSR_ROR;
}
- /* Attach to IRQ */
- irq = platform_get_irq(pdev, 0);
- if (irq < 0) {
- dev_err(&pdev->dev, "irq resource not defined\n");
- status = -ENODEV;
- goto out_error_master_alloc;
- }
-
- status = request_irq(irq, ssp_int, 0, dev->bus_id, drv_data);
+ status = request_irq(ssp->irq, ssp_int, 0, dev->bus_id, drv_data);
if (status < 0) {
dev_err(&pdev->dev, "can not get IRQ\n");
goto out_error_master_alloc;
goto out_error_dma_alloc;
}
- if (drv_data->ioaddr == SSP1_VIRT) {
- DRCMRRXSSDR = DRCMR_MAPVLD
- | drv_data->rx_channel;
- DRCMRTXSSDR = DRCMR_MAPVLD
- | drv_data->tx_channel;
- } else if (drv_data->ioaddr == SSP2_VIRT) {
- DRCMRRXSS2DR = DRCMR_MAPVLD
- | drv_data->rx_channel;
- DRCMRTXSS2DR = DRCMR_MAPVLD
- | drv_data->tx_channel;
- } else if (drv_data->ioaddr == SSP3_VIRT) {
- DRCMRRXSS3DR = DRCMR_MAPVLD
- | drv_data->rx_channel;
- DRCMRTXSS3DR = DRCMR_MAPVLD
- | drv_data->tx_channel;
- } else {
- dev_err(dev, "bad SSP type\n");
- 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 */
- pxa_set_cken(platform_info->clock_enable, 1);
+ clk_enable(ssp->clk);
/* Load default SSP configuration */
write_SSCR0(0, drv_data->ioaddr);
destroy_queue(drv_data);
out_error_clock_enabled:
- pxa_set_cken(platform_info->clock_enable, 0);
+ clk_disable(ssp->clk);
out_error_dma_alloc:
if (drv_data->tx_channel != -1)
pxa_free_dma(drv_data->rx_channel);
out_error_irq_alloc:
- free_irq(irq, drv_data);
+ free_irq(ssp->irq, drv_data);
out_error_master_alloc:
spi_master_put(master);
+ ssp_free(ssp);
return status;
}
static int pxa2xx_spi_remove(struct platform_device *pdev)
{
struct driver_data *drv_data = platform_get_drvdata(pdev);
- int irq;
+ struct ssp_device *ssp = drv_data->ssp;
int status = 0;
if (!drv_data)
/* Disable the SSP at the peripheral and SOC level */
write_SSCR0(0, drv_data->ioaddr);
- pxa_set_cken(drv_data->master_info->clock_enable, 0);
+ clk_disable(ssp->clk);
/* Release DMA */
if (drv_data->master_info->enable_dma) {
- if (drv_data->ioaddr == SSP1_VIRT) {
- DRCMRRXSSDR = 0;
- DRCMRTXSSDR = 0;
- } else if (drv_data->ioaddr == SSP2_VIRT) {
- DRCMRRXSS2DR = 0;
- DRCMRTXSS2DR = 0;
- } else if (drv_data->ioaddr == SSP3_VIRT) {
- DRCMRRXSS3DR = 0;
- DRCMRTXSS3DR = 0;
- }
+ 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 */
- irq = platform_get_irq(pdev, 0);
- if (irq >= 0)
- free_irq(irq, drv_data);
+ free_irq(ssp->irq, drv_data);
+
+ /* Release SSP */
+ ssp_free(ssp);
/* Disconnect from the SPI framework */
spi_unregister_master(drv_data->master);
}
#ifdef CONFIG_PM
-static int suspend_devices(struct device *dev, void *pm_message)
-{
- pm_message_t *state = pm_message;
-
- if (dev->power.power_state.event != state->event) {
- dev_warn(dev, "pm state does not match request\n");
- return -1;
- }
-
- return 0;
-}
static int pxa2xx_spi_suspend(struct platform_device *pdev, pm_message_t state)
{
struct driver_data *drv_data = platform_get_drvdata(pdev);
+ struct ssp_device *ssp = drv_data->ssp;
int status = 0;
- /* Check all childern for current power state */
- if (device_for_each_child(&pdev->dev, &state, suspend_devices) != 0) {
- dev_warn(&pdev->dev, "suspend aborted\n");
- return -1;
- }
-
status = stop_queue(drv_data);
if (status != 0)
return status;
write_SSCR0(0, drv_data->ioaddr);
- pxa_set_cken(drv_data->master_info->clock_enable, 0);
+ clk_disable(ssp->clk);
return 0;
}
static int pxa2xx_spi_resume(struct platform_device *pdev)
{
struct driver_data *drv_data = platform_get_drvdata(pdev);
+ struct ssp_device *ssp = drv_data->ssp;
int status = 0;
/* Enable the SSP clock */
- pxa_set_cken(drv_data->master_info->clock_enable, 1);
+ clk_disable(ssp->clk);
/* Start the queue running */
status = start_queue(drv_data);
static struct platform_driver driver = {
.driver = {
.name = "pxa2xx-spi",
- .bus = &platform_bus_type,
.owner = THIS_MODULE,
},
.remove = pxa2xx_spi_remove,
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