aboutsummaryrefslogtreecommitdiff
path: root/Documentation/spi
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/spi')
-rw-r--r--Documentation/spi/ep93xx_spi95
-rw-r--r--Documentation/spi/spidev_fdx.c4
-rw-r--r--Documentation/spi/spidev_test.c2
3 files changed, 98 insertions, 3 deletions
diff --git a/Documentation/spi/ep93xx_spi b/Documentation/spi/ep93xx_spi
new file mode 100644
index 00000000000..6325f5b4863
--- /dev/null
+++ b/Documentation/spi/ep93xx_spi
@@ -0,0 +1,95 @@
+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 <mach/ep93xx_spi.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));
+}
+
+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.
diff --git a/Documentation/spi/spidev_fdx.c b/Documentation/spi/spidev_fdx.c
index fc354f76038..36ec0774ca0 100644
--- a/Documentation/spi/spidev_fdx.c
+++ b/Documentation/spi/spidev_fdx.c
@@ -58,10 +58,10 @@ static void do_msg(int fd, int len)
len = sizeof buf;
buf[0] = 0xaa;
- xfer[0].tx_buf = (__u64) buf;
+ xfer[0].tx_buf = (unsigned long)buf;
xfer[0].len = 1;
- xfer[1].rx_buf = (__u64) buf;
+ xfer[1].rx_buf = (unsigned long) buf;
xfer[1].len = len;
status = ioctl(fd, SPI_IOC_MESSAGE(2), xfer);
diff --git a/Documentation/spi/spidev_test.c b/Documentation/spi/spidev_test.c
index 10abd3773e4..16feda90146 100644
--- a/Documentation/spi/spidev_test.c
+++ b/Documentation/spi/spidev_test.c
@@ -58,7 +58,7 @@ static void transfer(int fd)
};
ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr);
- if (ret == 1)
+ if (ret < 1)
pabort("can't send spi message");
for (ret = 0; ret < ARRAY_SIZE(tx); ret++) {