+++ /dev/null
-Cirrus EP93xx SPI controller driver HOWTO
-=========================================
-
-ep93xx_spi driver brings SPI master support for EP93xx SPI controller. Chip
-selects are implemented with GPIO lines.
-
-NOTE: If possible, don't use SFRMOUT (SFRM1) signal as a chip select. It will
-not work correctly (it cannot be controlled by software). Use GPIO lines
-instead.
-
-Sample configuration
-====================
-
-Typically driver configuration is done in platform board files (the files under
-arch/arm/mach-ep93xx/*.c). In this example we configure MMC over SPI through
-this driver on TS-7260 board. You can adapt the code to suit your needs.
-
-This example uses EGPIO9 as SD/MMC card chip select (this is wired in DIO1
-header on the board).
-
-You need to select CONFIG_MMC_SPI to use mmc_spi driver.
-
-arch/arm/mach-ep93xx/ts72xx.c:
-
-...
-#include <linux/gpio.h>
-#include <linux/spi/spi.h>
-
-#include <linux/platform_data/spi-ep93xx.h>
-
-/* this is our GPIO line used for chip select */
-#define MMC_CHIP_SELECT_GPIO EP93XX_GPIO_LINE_EGPIO9
-
-static int ts72xx_mmc_spi_setup(struct spi_device *spi)
-{
- int err;
-
- err = gpio_request(MMC_CHIP_SELECT_GPIO, spi->modalias);
- if (err)
- return err;
-
- gpio_direction_output(MMC_CHIP_SELECT_GPIO, 1);
-
- return 0;
-}
-
-static void ts72xx_mmc_spi_cleanup(struct spi_device *spi)
-{
- gpio_set_value(MMC_CHIP_SELECT_GPIO, 1);
- gpio_direction_input(MMC_CHIP_SELECT_GPIO);
- gpio_free(MMC_CHIP_SELECT_GPIO);
-}
-
-static void ts72xx_mmc_spi_cs_control(struct spi_device *spi, int value)
-{
- gpio_set_value(MMC_CHIP_SELECT_GPIO, value);
-}
-
-static struct ep93xx_spi_chip_ops ts72xx_mmc_spi_ops = {
- .setup = ts72xx_mmc_spi_setup,
- .cleanup = ts72xx_mmc_spi_cleanup,
- .cs_control = ts72xx_mmc_spi_cs_control,
-};
-
-static struct spi_board_info ts72xx_spi_devices[] __initdata = {
- {
- .modalias = "mmc_spi",
- .controller_data = &ts72xx_mmc_spi_ops,
- /*
- * We use 10 MHz even though the maximum is 7.4 MHz. The driver
- * will limit it automatically to max. frequency.
- */
- .max_speed_hz = 10 * 1000 * 1000,
- .bus_num = 0,
- .chip_select = 0,
- .mode = SPI_MODE_0,
- },
-};
-
-static struct ep93xx_spi_info ts72xx_spi_info = {
- .num_chipselect = ARRAY_SIZE(ts72xx_spi_devices),
-};
-
-static void __init ts72xx_init_machine(void)
-{
- ...
- ep93xx_register_spi(&ts72xx_spi_info, ts72xx_spi_devices,
- ARRAY_SIZE(ts72xx_spi_devices));
-}
-
-The driver can use DMA for the transfers also. In this case ts72xx_spi_info
-becomes:
-
-static struct ep93xx_spi_info ts72xx_spi_info = {
- .num_chipselect = ARRAY_SIZE(ts72xx_spi_devices),
- .use_dma = true;
-};
-
-Note that CONFIG_EP93XX_DMA should be enabled as well.
-
-Thanks to
-=========
-Martin Guy, H. Hartley Sweeten and others who helped me during development of
-the driver. Simplemachines.it donated me a Sim.One board which I used testing
-the driver on EP9307.
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
-#include <linux/gpio.h>
#include <linux/i2c.h>
#include <linux/i2c-gpio.h>
#include <linux/spi/spi.h>
.gpio_nreset = -EINVAL, /* filled in later */
};
-static int edb93xx_cs4271_hw_setup(struct spi_device *spi)
-{
- return gpio_request_one(EP93XX_GPIO_LINE_EGPIO6,
- GPIOF_OUT_INIT_HIGH, spi->modalias);
-}
-
-static void edb93xx_cs4271_hw_cleanup(struct spi_device *spi)
-{
- gpio_free(EP93XX_GPIO_LINE_EGPIO6);
-}
-
-static void edb93xx_cs4271_hw_cs_control(struct spi_device *spi, int value)
-{
- gpio_set_value(EP93XX_GPIO_LINE_EGPIO6, value);
-}
-
-static struct ep93xx_spi_chip_ops edb93xx_cs4271_hw = {
- .setup = edb93xx_cs4271_hw_setup,
- .cleanup = edb93xx_cs4271_hw_cleanup,
- .cs_control = edb93xx_cs4271_hw_cs_control,
-};
-
static struct spi_board_info edb93xx_spi_board_info[] __initdata = {
{
.modalias = "cs4271",
.platform_data = &edb93xx_cs4271_data,
- .controller_data = &edb93xx_cs4271_hw,
.max_speed_hz = 6000000,
.bus_num = 0,
.chip_select = 0,
},
};
+static int edb93xx_spi_chipselects[] __initdata = {
+ EP93XX_GPIO_LINE_EGPIO6,
+};
+
static struct ep93xx_spi_info edb93xx_spi_info __initdata = {
- .num_chipselect = ARRAY_SIZE(edb93xx_spi_board_info),
+ .chipselect = edb93xx_spi_chipselects,
+ .num_chipselect = ARRAY_SIZE(edb93xx_spi_chipselects),
};
static void __init edb93xx_register_spi(void)
*/
#define MMC_CARD_DETECT_GPIO EP93XX_GPIO_LINE_EGPIO0
-/*
- * Up to v1.3, the Sim.One used SFRMOUT as SD card chip select, but this goes
- * low between multi-message command blocks. From v1.4, it uses a GPIO instead.
- * v1.3 parts will still work, since the signal on SFRMOUT is automatic.
- */
-#define MMC_CHIP_SELECT_GPIO EP93XX_GPIO_LINE_EGPIO1
-
-/*
- * MMC SPI chip select GPIO handling. If you are using SFRMOUT (SFRM1) signal,
- * you can leave these empty and pass NULL as .controller_data.
- */
-
-static int simone_mmc_spi_setup(struct spi_device *spi)
-{
- unsigned int gpio = MMC_CHIP_SELECT_GPIO;
- int err;
-
- err = gpio_request(gpio, spi->modalias);
- if (err)
- return err;
-
- err = gpio_direction_output(gpio, 1);
- if (err) {
- gpio_free(gpio);
- return err;
- }
-
- return 0;
-}
-
-static void simone_mmc_spi_cleanup(struct spi_device *spi)
-{
- unsigned int gpio = MMC_CHIP_SELECT_GPIO;
-
- gpio_set_value(gpio, 1);
- gpio_direction_input(gpio);
- gpio_free(gpio);
-}
-
-static void simone_mmc_spi_cs_control(struct spi_device *spi, int value)
-{
- gpio_set_value(MMC_CHIP_SELECT_GPIO, value);
-}
-
-static struct ep93xx_spi_chip_ops simone_mmc_spi_ops = {
- .setup = simone_mmc_spi_setup,
- .cleanup = simone_mmc_spi_cleanup,
- .cs_control = simone_mmc_spi_cs_control,
-};
-
/*
* MMC card detection GPIO setup.
*/
static struct spi_board_info simone_spi_devices[] __initdata = {
{
.modalias = "mmc_spi",
- .controller_data = &simone_mmc_spi_ops,
.platform_data = &simone_mmc_spi_data,
/*
* We use 10 MHz even though the maximum is 3.7 MHz. The driver
},
};
+/*
+ * Up to v1.3, the Sim.One used SFRMOUT as SD card chip select, but this goes
+ * low between multi-message command blocks. From v1.4, it uses a GPIO instead.
+ * v1.3 parts will still work, since the signal on SFRMOUT is automatic.
+ */
+static int simone_spi_chipselects[] __initdata = {
+ EP93XX_GPIO_LINE_EGPIO1,
+};
+
static struct ep93xx_spi_info simone_spi_info __initdata = {
- .num_chipselect = ARRAY_SIZE(simone_spi_devices),
+ .chipselect = simone_spi_chipselects,
+ .num_chipselect = ARRAY_SIZE(simone_spi_chipselects),
.use_dma = 1,
};
.gpio_nreset = EP93XX_GPIO_LINE_H(2),
};
-static int vision_cs4271_hw_setup(struct spi_device *spi)
-{
- return gpio_request_one(EP93XX_GPIO_LINE_EGPIO6,
- GPIOF_OUT_INIT_HIGH, spi->modalias);
-}
-
-static void vision_cs4271_hw_cleanup(struct spi_device *spi)
-{
- gpio_free(EP93XX_GPIO_LINE_EGPIO6);
-}
-
-static void vision_cs4271_hw_cs_control(struct spi_device *spi, int value)
-{
- gpio_set_value(EP93XX_GPIO_LINE_EGPIO6, value);
-}
-
-static struct ep93xx_spi_chip_ops vision_cs4271_hw = {
- .setup = vision_cs4271_hw_setup,
- .cleanup = vision_cs4271_hw_cleanup,
- .cs_control = vision_cs4271_hw_cs_control,
-};
-
/*************************************************************************
* SPI Flash
*************************************************************************/
-#define VISION_SPI_FLASH_CS EP93XX_GPIO_LINE_EGPIO7
-
static struct mtd_partition vision_spi_flash_partitions[] = {
{
.name = "SPI bootstrap",
.nr_parts = ARRAY_SIZE(vision_spi_flash_partitions),
};
-static int vision_spi_flash_hw_setup(struct spi_device *spi)
-{
- return gpio_request_one(VISION_SPI_FLASH_CS, GPIOF_INIT_HIGH,
- spi->modalias);
-}
-
-static void vision_spi_flash_hw_cleanup(struct spi_device *spi)
-{
- gpio_free(VISION_SPI_FLASH_CS);
-}
-
-static void vision_spi_flash_hw_cs_control(struct spi_device *spi, int value)
-{
- gpio_set_value(VISION_SPI_FLASH_CS, value);
-}
-
-static struct ep93xx_spi_chip_ops vision_spi_flash_hw = {
- .setup = vision_spi_flash_hw_setup,
- .cleanup = vision_spi_flash_hw_cleanup,
- .cs_control = vision_spi_flash_hw_cs_control,
-};
-
/*************************************************************************
* SPI SD/MMC host
*************************************************************************/
-#define VISION_SPI_MMC_CS EP93XX_GPIO_LINE_G(2)
-#define VISION_SPI_MMC_WP EP93XX_GPIO_LINE_F(0)
-#define VISION_SPI_MMC_CD EP93XX_GPIO_LINE_EGPIO15
-
static struct mmc_spi_platform_data vision_spi_mmc_data = {
.detect_delay = 100,
.powerup_msecs = 100,
.ocr_mask = MMC_VDD_32_33 | MMC_VDD_33_34,
.flags = MMC_SPI_USE_CD_GPIO | MMC_SPI_USE_RO_GPIO,
- .cd_gpio = VISION_SPI_MMC_CD,
+ .cd_gpio = EP93XX_GPIO_LINE_EGPIO15,
.cd_debounce = 1,
- .ro_gpio = VISION_SPI_MMC_WP,
+ .ro_gpio = EP93XX_GPIO_LINE_F(0),
.caps2 = MMC_CAP2_RO_ACTIVE_HIGH,
};
-static int vision_spi_mmc_hw_setup(struct spi_device *spi)
-{
- return gpio_request_one(VISION_SPI_MMC_CS, GPIOF_INIT_HIGH,
- spi->modalias);
-}
-
-static void vision_spi_mmc_hw_cleanup(struct spi_device *spi)
-{
- gpio_free(VISION_SPI_MMC_CS);
-}
-
-static void vision_spi_mmc_hw_cs_control(struct spi_device *spi, int value)
-{
- gpio_set_value(VISION_SPI_MMC_CS, value);
-}
-
-static struct ep93xx_spi_chip_ops vision_spi_mmc_hw = {
- .setup = vision_spi_mmc_hw_setup,
- .cleanup = vision_spi_mmc_hw_cleanup,
- .cs_control = vision_spi_mmc_hw_cs_control,
-};
-
/*************************************************************************
* SPI Bus
*************************************************************************/
{
.modalias = "cs4271",
.platform_data = &vision_cs4271_data,
- .controller_data = &vision_cs4271_hw,
.max_speed_hz = 6000000,
.bus_num = 0,
.chip_select = 0,
}, {
.modalias = "sst25l",
.platform_data = &vision_spi_flash_data,
- .controller_data = &vision_spi_flash_hw,
.max_speed_hz = 20000000,
.bus_num = 0,
.chip_select = 1,
}, {
.modalias = "mmc_spi",
.platform_data = &vision_spi_mmc_data,
- .controller_data = &vision_spi_mmc_hw,
.max_speed_hz = 20000000,
.bus_num = 0,
.chip_select = 2,
},
};
+static int vision_spi_chipselects[] __initdata = {
+ EP93XX_GPIO_LINE_EGPIO6,
+ EP93XX_GPIO_LINE_EGPIO7,
+ EP93XX_GPIO_LINE_G(2),
+};
+
static struct ep93xx_spi_info vision_spi_master __initdata = {
- .num_chipselect = ARRAY_SIZE(vision_spi_board_info),
+ .chipselect = vision_spi_chipselects,
+ .num_chipselect = ARRAY_SIZE(vision_spi_chipselects),
.use_dma = 1,
};
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/scatterlist.h>
+#include <linux/gpio.h>
#include <linux/spi/spi.h>
#include <linux/platform_data/dma-ep93xx.h>
void *zeropage;
};
-/**
- * struct ep93xx_spi_chip - SPI device hardware settings
- * @spi: back pointer to the SPI device
- * @ops: private chip operations
- */
-struct ep93xx_spi_chip {
- const struct spi_device *spi;
- struct ep93xx_spi_chip_ops *ops;
-};
-
/* converts bits per word to CR0.DSS value */
#define bits_per_word_to_dss(bpw) ((bpw) - 1)
return -EINVAL;
}
-static void ep93xx_spi_cs_control(struct spi_device *spi, bool control)
-{
- struct ep93xx_spi_chip *chip = spi_get_ctldata(spi);
- int value = (spi->mode & SPI_CS_HIGH) ? control : !control;
-
- if (chip->ops && chip->ops->cs_control)
- chip->ops->cs_control(spi, value);
-}
-
-/**
- * ep93xx_spi_setup() - setup an SPI device
- * @spi: SPI device to setup
- *
- * This function sets up SPI device mode, speed etc. Can be called multiple
- * times for a single device. Returns %0 in case of success, negative error in
- * case of failure. When this function returns success, the device is
- * deselected.
- */
-static int ep93xx_spi_setup(struct spi_device *spi)
+static void ep93xx_spi_cs_control(struct spi_device *spi, bool enable)
{
- struct ep93xx_spi *espi = spi_master_get_devdata(spi->master);
- struct ep93xx_spi_chip *chip;
+ if (spi->mode & SPI_CS_HIGH)
+ enable = !enable;
- chip = spi_get_ctldata(spi);
- if (!chip) {
- dev_dbg(&espi->pdev->dev, "initial setup for %s\n",
- spi->modalias);
-
- chip = kzalloc(sizeof(*chip), GFP_KERNEL);
- if (!chip)
- return -ENOMEM;
-
- chip->spi = spi;
- chip->ops = spi->controller_data;
-
- if (chip->ops && chip->ops->setup) {
- int ret = chip->ops->setup(spi);
-
- if (ret) {
- kfree(chip);
- return ret;
- }
- }
-
- spi_set_ctldata(spi, chip);
- }
-
- ep93xx_spi_cs_control(spi, false);
- return 0;
+ if (gpio_is_valid(spi->cs_gpio))
+ gpio_set_value(spi->cs_gpio, !enable);
}
-/**
- * ep93xx_spi_cleanup() - cleans up master controller specific state
- * @spi: SPI device to cleanup
- *
- * This function releases master controller specific state for given @spi
- * device.
- */
-static void ep93xx_spi_cleanup(struct spi_device *spi)
-{
- struct ep93xx_spi_chip *chip;
-
- chip = spi_get_ctldata(spi);
- if (chip) {
- if (chip->ops && chip->ops->cleanup)
- chip->ops->cleanup(spi);
- spi_set_ctldata(spi, NULL);
- kfree(chip);
- }
-}
-
-/**
- * ep93xx_spi_chip_setup() - configures hardware according to given @chip
- * @espi: ep93xx SPI controller struct
- * @chip: chip specific settings
- * @speed_hz: transfer speed
- * @bits_per_word: transfer bits_per_word
- */
static int ep93xx_spi_chip_setup(const struct ep93xx_spi *espi,
- const struct ep93xx_spi_chip *chip,
- u32 speed_hz, u8 bits_per_word)
+ struct spi_device *spi,
+ struct spi_transfer *xfer)
{
- u8 dss = bits_per_word_to_dss(bits_per_word);
+ u8 dss = bits_per_word_to_dss(xfer->bits_per_word);
u8 div_cpsr = 0;
u8 div_scr = 0;
u16 cr0;
int err;
- err = ep93xx_spi_calc_divisors(espi, speed_hz, &div_cpsr, &div_scr);
+ err = ep93xx_spi_calc_divisors(espi, xfer->speed_hz,
+ &div_cpsr, &div_scr);
if (err)
return err;
cr0 = div_scr << SSPCR0_SCR_SHIFT;
- cr0 |= (chip->spi->mode & (SPI_CPHA|SPI_CPOL)) << SSPCR0_MODE_SHIFT;
+ cr0 |= (spi->mode & (SPI_CPHA | SPI_CPOL)) << SSPCR0_MODE_SHIFT;
cr0 |= dss;
dev_dbg(&espi->pdev->dev, "setup: mode %d, cpsr %d, scr %d, dss %d\n",
- chip->spi->mode, div_cpsr, div_scr, dss);
+ spi->mode, div_cpsr, div_scr, dss);
dev_dbg(&espi->pdev->dev, "setup: cr0 %#x\n", cr0);
ep93xx_spi_write_u8(espi, SSPCPSR, div_cpsr);
struct spi_message *msg,
struct spi_transfer *t)
{
- struct ep93xx_spi_chip *chip = spi_get_ctldata(msg->spi);
int err;
msg->state = t;
- err = ep93xx_spi_chip_setup(espi, chip, t->speed_hz, t->bits_per_word);
+ err = ep93xx_spi_chip_setup(espi, msg->spi, t);
if (err) {
dev_err(&espi->pdev->dev,
"failed to setup chip for transfer\n");
struct resource *res;
int irq;
int error;
+ int i;
info = dev_get_platdata(&pdev->dev);
+ if (!info) {
+ dev_err(&pdev->dev, "missing platform data\n");
+ return -EINVAL;
+ }
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
if (!master)
return -ENOMEM;
- master->setup = ep93xx_spi_setup;
master->transfer_one_message = ep93xx_spi_transfer_one_message;
- master->cleanup = ep93xx_spi_cleanup;
master->bus_num = pdev->id;
- master->num_chipselect = info->num_chipselect;
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
+ master->num_chipselect = info->num_chipselect;
+ master->cs_gpios = devm_kzalloc(&master->dev,
+ sizeof(int) * master->num_chipselect,
+ GFP_KERNEL);
+ if (!master->cs_gpios) {
+ error = -ENOMEM;
+ goto fail_release_master;
+ }
+
+ for (i = 0; i < master->num_chipselect; i++) {
+ master->cs_gpios[i] = info->chipselect[i];
+
+ if (!gpio_is_valid(master->cs_gpios[i]))
+ continue;
+
+ error = devm_gpio_request_one(&pdev->dev, master->cs_gpios[i],
+ GPIOF_OUT_INIT_HIGH,
+ "ep93xx-spi");
+ if (error) {
+ dev_err(&pdev->dev, "could not request cs gpio %d\n",
+ master->cs_gpios[i]);
+ goto fail_release_master;
+ }
+ }
+
platform_set_drvdata(pdev, master);
espi = spi_master_get_devdata(master);
/**
* struct ep93xx_spi_info - EP93xx specific SPI descriptor
- * @num_chipselect: number of chip selects on this board, must be
- * at least one
+ * @chipselect: array of gpio numbers to use as chip selects
+ * @num_chipselect: ARRAY_SIZE(chipselect)
* @use_dma: use DMA for the transfers
*/
struct ep93xx_spi_info {
+ int *chipselect;
int num_chipselect;
bool use_dma;
};
-/**
- * struct ep93xx_spi_chip_ops - operation callbacks for SPI slave device
- * @setup: setup the chip select mechanism
- * @cleanup: cleanup the chip select mechanism
- * @cs_control: control the device chip select
- */
-struct ep93xx_spi_chip_ops {
- int (*setup)(struct spi_device *spi);
- void (*cleanup)(struct spi_device *spi);
- void (*cs_control)(struct spi_device *spi, int value);
-};
-
#endif /* __ASM_MACH_EP93XX_SPI_H */
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff