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authorJiri Kosina <jkosina@suse.cz>2010-06-16 12:08:13 -0400
committerJiri Kosina <jkosina@suse.cz>2010-06-16 12:08:13 -0400
commitf1bbbb6912662b9f6070c5bfc4ca9eb1f06a9d5b (patch)
treec2c130a74be25b0b2dff992e1a195e2728bdaadd /Documentation/spi
parentfd0961ff67727482bb20ca7e8ea97b83e9de2ddb (diff)
parent7e27d6e778cd87b6f2415515d7127eba53fe5d02 (diff)
Merge branch 'master' into for-next
Diffstat (limited to 'Documentation/spi')
-rw-r--r--Documentation/spi/ep93xx_spi95
-rw-r--r--Documentation/spi/spidev_fdx.c4
2 files changed, 97 insertions, 2 deletions
diff --git a/Documentation/spi/ep93xx_spi b/Documentation/spi/ep93xx_spi
new file mode 100644
index 000000000000..6325f5b48635
--- /dev/null
+++ b/Documentation/spi/ep93xx_spi
@@ -0,0 +1,95 @@
1Cirrus EP93xx SPI controller driver HOWTO
2=========================================
3
4ep93xx_spi driver brings SPI master support for EP93xx SPI controller. Chip
5selects are implemented with GPIO lines.
6
7NOTE: If possible, don't use SFRMOUT (SFRM1) signal as a chip select. It will
8not work correctly (it cannot be controlled by software). Use GPIO lines
9instead.
10
11Sample configuration
12====================
13
14Typically driver configuration is done in platform board files (the files under
15arch/arm/mach-ep93xx/*.c). In this example we configure MMC over SPI through
16this driver on TS-7260 board. You can adapt the code to suit your needs.
17
18This example uses EGPIO9 as SD/MMC card chip select (this is wired in DIO1
19header on the board).
20
21You need to select CONFIG_MMC_SPI to use mmc_spi driver.
22
23arch/arm/mach-ep93xx/ts72xx.c:
24
25...
26#include <linux/gpio.h>
27#include <linux/spi/spi.h>
28
29#include <mach/ep93xx_spi.h>
30
31/* this is our GPIO line used for chip select */
32#define MMC_CHIP_SELECT_GPIO EP93XX_GPIO_LINE_EGPIO9
33
34static int ts72xx_mmc_spi_setup(struct spi_device *spi)
35{
36 int err;
37
38 err = gpio_request(MMC_CHIP_SELECT_GPIO, spi->modalias);
39 if (err)
40 return err;
41
42 gpio_direction_output(MMC_CHIP_SELECT_GPIO, 1);
43
44 return 0;
45}
46
47static void ts72xx_mmc_spi_cleanup(struct spi_device *spi)
48{
49 gpio_set_value(MMC_CHIP_SELECT_GPIO, 1);
50 gpio_direction_input(MMC_CHIP_SELECT_GPIO);
51 gpio_free(MMC_CHIP_SELECT_GPIO);
52}
53
54static void ts72xx_mmc_spi_cs_control(struct spi_device *spi, int value)
55{
56 gpio_set_value(MMC_CHIP_SELECT_GPIO, value);
57}
58
59static struct ep93xx_spi_chip_ops ts72xx_mmc_spi_ops = {
60 .setup = ts72xx_mmc_spi_setup,
61 .cleanup = ts72xx_mmc_spi_cleanup,
62 .cs_control = ts72xx_mmc_spi_cs_control,
63};
64
65static struct spi_board_info ts72xx_spi_devices[] __initdata = {
66 {
67 .modalias = "mmc_spi",
68 .controller_data = &ts72xx_mmc_spi_ops,
69 /*
70 * We use 10 MHz even though the maximum is 7.4 MHz. The driver
71 * will limit it automatically to max. frequency.
72 */
73 .max_speed_hz = 10 * 1000 * 1000,
74 .bus_num = 0,
75 .chip_select = 0,
76 .mode = SPI_MODE_0,
77 },
78};
79
80static struct ep93xx_spi_info ts72xx_spi_info = {
81 .num_chipselect = ARRAY_SIZE(ts72xx_spi_devices),
82};
83
84static void __init ts72xx_init_machine(void)
85{
86 ...
87 ep93xx_register_spi(&ts72xx_spi_info, ts72xx_spi_devices,
88 ARRAY_SIZE(ts72xx_spi_devices));
89}
90
91Thanks to
92=========
93Martin Guy, H. Hartley Sweeten and others who helped me during development of
94the driver. Simplemachines.it donated me a Sim.One board which I used testing
95the driver on EP9307.
diff --git a/Documentation/spi/spidev_fdx.c b/Documentation/spi/spidev_fdx.c
index fc354f760384..36ec0774ca0b 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)
58 len = sizeof buf; 58 len = sizeof buf;
59 59
60 buf[0] = 0xaa; 60 buf[0] = 0xaa;
61 xfer[0].tx_buf = (__u64) buf; 61 xfer[0].tx_buf = (unsigned long)buf;
62 xfer[0].len = 1; 62 xfer[0].len = 1;
63 63
64 xfer[1].rx_buf = (__u64) buf; 64 xfer[1].rx_buf = (unsigned long) buf;
65 xfer[1].len = len; 65 xfer[1].len = len;
66 66
67 status = ioctl(fd, SPI_IOC_MESSAGE(2), xfer); 67 status = ioctl(fd, SPI_IOC_MESSAGE(2), xfer);