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authorLinus Torvalds <torvalds@linux-foundation.org>2014-12-14 12:54:40 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-12-14 12:54:40 -0800
commit96895199c8648db475b38aac5fe6a04ec14a49c4 (patch)
tree3cb2a2a68a4750de20cf3deddd4a897189164ea9 /drivers/misc
parent8fd9589ced9a4ab1cf23296fa1c17d07e883f734 (diff)
parent6cf710d47633be388e831713738626d1911163c8 (diff)
Merge branch 'i2c/for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang: "For 3.19, the I2C subsystem has to offer special candy this time. Right in time for Christmas :) - I2C slave framework: finally, a generic mechanism for Linux being an I2C slave (if the bus driver supports that). Docs are still missing but will come later this cycle, the code is good enough to go. - I2C muxes represent their topology in sysfs much more detailed. This will help users to navigate around much easier. - irq population of i2c clients is now done at probe time, not device creation time, to have better support for deferred probing. - new drivers for Imagination SCB, Amlogic Meson - DMA support added for Freescale IMX, Renesas SHMobile - slightly bigger driver updates to OMAP, i801, AT91, and rk3x (mostly quirk handling, timing updates, and using better kernel interfaces) - eeprom driver can now write with byte-access (very slow, but OK to have) - and the bunch of smaller fixes, cleanups, ID updates..." * 'i2c/for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (56 commits) i2c: sh_mobile: remove unneeded DMA mask i2c: rcar: add slave support i2c: slave-eeprom: add eeprom simulator driver i2c: core changes for slave support MAINTAINERS: add I2C dt bindings also to I2C realm i2c: designware: Fix falling time bindings doc i2c: davinci: switch to use platform_get_irq Documentation: i2c: Use PM ops instead of legacy suspend/resume i2c: sh_mobile: optimize irq entry i2c: pxa: add support for SCCB devices omap: i2c: don't check bus state IP rev3.3 and earlier i2c: s3c2410: Handle i2c sys_cfg register in i2c driver i2c: rk3x: add Kconfig dependency on COMMON_CLK i2c: omap: add notes related to i2c multimaster mode i2c: omap: don't reset controller if Arbitration Lost detected i2c: omap: implement workaround for handling invalid BB-bit values i2c: omap: cleanup register definitions i2c: rk3x: handle dynamic clock rate changes correctly i2c: at91: enable probe deferring on dma channel request i2c: at91: remove legacy DMA support ...
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/eeprom/at24.c35
1 files changed, 29 insertions, 6 deletions
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index d87f77f790d6..2d3db81be099 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -56,6 +56,7 @@ struct at24_data {
struct at24_platform_data chip;
struct memory_accessor macc;
int use_smbus;
+ int use_smbus_write;
/*
* Lock protects against activities from other Linux tasks,
@@ -324,7 +325,7 @@ static ssize_t at24_eeprom_write(struct at24_data *at24, const char *buf,
{
struct i2c_client *client;
struct i2c_msg msg;
- ssize_t status;
+ ssize_t status = 0;
unsigned long timeout, write_time;
unsigned next_page;
@@ -365,9 +366,18 @@ static ssize_t at24_eeprom_write(struct at24_data *at24, const char *buf,
timeout = jiffies + msecs_to_jiffies(write_timeout);
do {
write_time = jiffies;
- if (at24->use_smbus) {
- status = i2c_smbus_write_i2c_block_data(client,
- offset, count, buf);
+ if (at24->use_smbus_write) {
+ switch (at24->use_smbus_write) {
+ case I2C_SMBUS_I2C_BLOCK_DATA:
+ status = i2c_smbus_write_i2c_block_data(client,
+ offset, count, buf);
+ break;
+ case I2C_SMBUS_BYTE_DATA:
+ status = i2c_smbus_write_byte_data(client,
+ offset, buf[0]);
+ break;
+ }
+
if (status == 0)
status = count;
} else {
@@ -487,6 +497,7 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
struct at24_platform_data chip;
bool writable;
int use_smbus = 0;
+ int use_smbus_write = 0;
struct at24_data *at24;
int err;
unsigned i, num_addresses;
@@ -546,6 +557,18 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
}
}
+ /* Use I2C operations unless we're stuck with SMBus extensions. */
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+ if (i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) {
+ use_smbus_write = I2C_SMBUS_I2C_BLOCK_DATA;
+ } else if (i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
+ use_smbus_write = I2C_SMBUS_BYTE_DATA;
+ chip.page_size = 1;
+ }
+ }
+
if (chip.flags & AT24_FLAG_TAKE8ADDR)
num_addresses = 8;
else
@@ -559,6 +582,7 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
mutex_init(&at24->lock);
at24->use_smbus = use_smbus;
+ at24->use_smbus_write = use_smbus_write;
at24->chip = chip;
at24->num_addresses = num_addresses;
@@ -576,8 +600,7 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
writable = !(chip.flags & AT24_FLAG_READONLY);
if (writable) {
- if (!use_smbus || i2c_check_functionality(client->adapter,
- I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) {
+ if (!use_smbus || use_smbus_write) {
unsigned write_max = chip.page_size;