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authorLinus Torvalds <torvalds@linux-foundation.org>2012-12-13 19:15:11 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-13 19:15:11 -0800
commitd3b43e12b2c8c69f79ab76dcdc5956f47c376378 (patch)
tree4fba9e425d7407e5abd5ab50d5ac09398ec5bff6 /drivers/spi/spi.c
parent15de0599277f3477ddd11766282587f12d214252 (diff)
parent7cb943615aabbd72624f77f0a84b8c5d627cf846 (diff)
Merge tag 'spi-for-linus' of git://git.secretlab.ca/git/linux-2.6
Pull SPI updates from Grant Likely: "Primarily SPI device driver bug fixes, one removal of an old driver, and some new tegra support. There is some core code change too, but all in all pretty small stuff. The new features to note are: - Common code for describing GPIO CS lines in the device tree - Remove the SPI_BUFSIZ limitation on spi_write_the_read() - core spi ensures bits_per_word is set correctly - SPARC can now use SPI" * tag 'spi-for-linus' of git://git.secretlab.ca/git/linux-2.6: (36 commits) spi/sparc: Allow of_register_spi_devices for sparc spi: Remove HOTPLUG section attributes spi: Add support for specifying 3-wire mode via device tree spi: Fix comparison of different integer types spi/orion: Add SPI_CHPA and SPI_CPOL support to kirkwood driver. spi/sh: Add SH Mobile series as dependency to MSIOF controller spi/sh-msiof: Remove unneeded clock name spi: Remove SPI_BUFSIZ restriction on spi_write_then_read() spi/stmp: remove obsolete driver spi/clps711x: New SPI master driver spi: omap2-mcspi: remove duplicate inclusion of linux/err.h spi: omap2-mcspi: Fix the redifine warning spi/sh-hspi: add CS manual control support of_spi: add generic binding support to specify cs gpio spi: omap2-mcspi: remove duplicated include from spi-omap2-mcspi.c spi/bitbang: (cosmetic) simplify list manipulation spi/bitbang: avoid needless loop flow manipulations spi/omap: fix D0/D1 direction confusion spi: tegra: add spi driver for sflash controller spi: Dont call master->setup if not populated ...
Diffstat (limited to 'drivers/spi/spi.c')
-rw-r--r--drivers/spi/spi.c101
1 files changed, 79 insertions, 22 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 718cc1f4923..ab095acdb2a 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -30,6 +30,7 @@
#include <linux/slab.h>
#include <linux/mod_devicetable.h>
#include <linux/spi/spi.h>
+#include <linux/of_gpio.h>
#include <linux/pm_runtime.h>
#include <linux/export.h>
#include <linux/sched.h>
@@ -333,6 +334,7 @@ struct spi_device *spi_alloc_device(struct spi_master *master)
spi->dev.parent = &master->dev;
spi->dev.bus = &spi_bus_type;
spi->dev.release = spidev_release;
+ spi->cs_gpio = -EINVAL;
device_initialize(&spi->dev);
return spi;
}
@@ -350,15 +352,16 @@ EXPORT_SYMBOL_GPL(spi_alloc_device);
int spi_add_device(struct spi_device *spi)
{
static DEFINE_MUTEX(spi_add_lock);
- struct device *dev = spi->master->dev.parent;
+ struct spi_master *master = spi->master;
+ struct device *dev = master->dev.parent;
struct device *d;
int status;
/* Chipselects are numbered 0..max; validate. */
- if (spi->chip_select >= spi->master->num_chipselect) {
+ if (spi->chip_select >= master->num_chipselect) {
dev_err(dev, "cs%d >= max %d\n",
spi->chip_select,
- spi->master->num_chipselect);
+ master->num_chipselect);
return -EINVAL;
}
@@ -382,6 +385,9 @@ int spi_add_device(struct spi_device *spi)
goto done;
}
+ if (master->cs_gpios)
+ spi->cs_gpio = master->cs_gpios[spi->chip_select];
+
/* Drivers may modify this initial i/o setup, but will
* normally rely on the device being setup. Devices
* using SPI_CS_HIGH can't coexist well otherwise...
@@ -492,8 +498,7 @@ static void spi_match_master_to_boardinfo(struct spi_master *master,
* The board info passed can safely be __initdata ... but be careful of
* any embedded pointers (platform_data, etc), they're copied as-is.
*/
-int __devinit
-spi_register_board_info(struct spi_board_info const *info, unsigned n)
+int spi_register_board_info(struct spi_board_info const *info, unsigned n)
{
struct boardinfo *bi;
int i;
@@ -806,7 +811,7 @@ err_init_queue:
/*-------------------------------------------------------------------------*/
-#if defined(CONFIG_OF) && !defined(CONFIG_SPARC)
+#if defined(CONFIG_OF)
/**
* of_register_spi_devices() - Register child devices onto the SPI bus
* @master: Pointer to spi_master device
@@ -861,6 +866,8 @@ static void of_register_spi_devices(struct spi_master *master)
spi->mode |= SPI_CPOL;
if (of_find_property(nc, "spi-cs-high", NULL))
spi->mode |= SPI_CS_HIGH;
+ if (of_find_property(nc, "spi-3wire", NULL))
+ spi->mode |= SPI_3WIRE;
/* Device speed */
prop = of_get_property(nc, "spi-max-frequency", &len);
@@ -1046,6 +1053,44 @@ struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
}
EXPORT_SYMBOL_GPL(spi_alloc_master);
+#ifdef CONFIG_OF
+static int of_spi_register_master(struct spi_master *master)
+{
+ u16 nb;
+ int i, *cs;
+ struct device_node *np = master->dev.of_node;
+
+ if (!np)
+ return 0;
+
+ nb = of_gpio_named_count(np, "cs-gpios");
+ master->num_chipselect = max(nb, master->num_chipselect);
+
+ if (nb < 1)
+ return 0;
+
+ cs = devm_kzalloc(&master->dev,
+ sizeof(int) * master->num_chipselect,
+ GFP_KERNEL);
+ master->cs_gpios = cs;
+
+ if (!master->cs_gpios)
+ return -ENOMEM;
+
+ memset(cs, -EINVAL, master->num_chipselect);
+
+ for (i = 0; i < nb; i++)
+ cs[i] = of_get_named_gpio(np, "cs-gpios", i);
+
+ return 0;
+}
+#else
+static int of_spi_register_master(struct spi_master *master)
+{
+ return 0;
+}
+#endif
+
/**
* spi_register_master - register SPI master controller
* @master: initialized master, originally from spi_alloc_master()
@@ -1077,6 +1122,10 @@ int spi_register_master(struct spi_master *master)
if (!dev)
return -ENODEV;
+ status = of_spi_register_master(master);
+ if (status)
+ return status;
+
/* even if it's just one always-selected device, there must
* be at least one chipselect
*/
@@ -1257,7 +1306,7 @@ EXPORT_SYMBOL_GPL(spi_busnum_to_master);
int spi_setup(struct spi_device *spi)
{
unsigned bad_bits;
- int status;
+ int status = 0;
/* help drivers fail *cleanly* when they need options
* that aren't supported with their current master
@@ -1272,7 +1321,8 @@ int spi_setup(struct spi_device *spi)
if (!spi->bits_per_word)
spi->bits_per_word = 8;
- status = spi->master->setup(spi);
+ if (spi->master->setup)
+ status = spi->master->setup(spi);
dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s"
"%u bits/w, %u Hz max --> %d\n",
@@ -1291,6 +1341,7 @@ EXPORT_SYMBOL_GPL(spi_setup);
static int __spi_async(struct spi_device *spi, struct spi_message *message)
{
struct spi_master *master = spi->master;
+ struct spi_transfer *xfer;
/* Half-duplex links include original MicroWire, and ones with
* only one data pin like SPI_3WIRE (switches direction) or where
@@ -1299,7 +1350,6 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message)
*/
if ((master->flags & SPI_MASTER_HALF_DUPLEX)
|| (spi->mode & SPI_3WIRE)) {
- struct spi_transfer *xfer;
unsigned flags = master->flags;
list_for_each_entry(xfer, &message->transfers, transfer_list) {
@@ -1312,6 +1362,15 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message)
}
}
+ /**
+ * Set transfer bits_per_word as spi device default if it is not
+ * set for this transfer.
+ */
+ list_for_each_entry(xfer, &message->transfers, transfer_list) {
+ if (!xfer->bits_per_word)
+ xfer->bits_per_word = spi->bits_per_word;
+ }
+
message->spi = spi;
message->status = -EINPROGRESS;
return master->transfer(spi, message);
@@ -1588,12 +1647,18 @@ int spi_write_then_read(struct spi_device *spi,
struct spi_transfer x[2];
u8 *local_buf;
- /* Use preallocated DMA-safe buffer. We can't avoid copying here,
- * (as a pure convenience thing), but we can keep heap costs
- * out of the hot path ...
+ /* Use preallocated DMA-safe buffer if we can. We can't avoid
+ * copying here, (as a pure convenience thing), but we can
+ * keep heap costs out of the hot path unless someone else is
+ * using the pre-allocated buffer or the transfer is too large.
*/
- if ((n_tx + n_rx) > SPI_BUFSIZ)
- return -EINVAL;
+ if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
+ local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx), GFP_KERNEL);
+ if (!local_buf)
+ return -ENOMEM;
+ } else {
+ local_buf = buf;
+ }
spi_message_init(&message);
memset(x, 0, sizeof x);
@@ -1606,14 +1671,6 @@ int spi_write_then_read(struct spi_device *spi,
spi_message_add_tail(&x[1], &message);
}
- /* ... unless someone else is using the pre-allocated buffer */
- if (!mutex_trylock(&lock)) {
- local_buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
- if (!local_buf)
- return -ENOMEM;
- } else
- local_buf = buf;
-
memcpy(local_buf, txbuf, n_tx);
x[0].tx_buf = local_buf;
x[1].rx_buf = local_buf + n_tx;