diff --git a/Documentation/i2c/dev-interface b/Documentation/i2c/dev-interface
index d04e6e4964ee7f88387f2e0e9ce3803b96d4ae18..fbed645ccd7563e90e86796d13cae7cfa7329748 100644
--- a/Documentation/i2c/dev-interface
+++ b/Documentation/i2c/dev-interface
@@ -9,8 +9,8 @@ i2c adapters present on your system at a given time. i2cdetect is part of
the i2c-tools package.
I2C device files are character device files with major device number 89
-and a minor device number corresponding to the number assigned as
-explained above. They should be called "i2c-%d" (i2c-0, i2c-1, ...,
+and a minor device number corresponding to the number assigned as
+explained above. They should be called "i2c-%d" (i2c-0, i2c-1, ...,
i2c-10, ...). All 256 minor device numbers are reserved for i2c.
@@ -23,11 +23,6 @@ First, you need to include these two headers:
#include <linux/i2c-dev.h>
#include <i2c/smbus.h>
-(Please note that there are two files named "i2c-dev.h" out there. One is
-distributed with the Linux kernel and the other one is included in the
-source tree of i2c-tools. They used to be different in content but since 2012
-they're identical. You should use "linux/i2c-dev.h").
-
Now, you have to decide which adapter you want to access. You should
inspect /sys/class/i2c-dev/ or run "i2cdetect -l" to decide this.
Adapter numbers are assigned somewhat dynamically, so you can not
@@ -38,7 +33,7 @@ Next thing, open the device file, as follows:
int file;
int adapter_nr = 2; /* probably dynamically determined */
char filename[20];
-
+
snprintf(filename, 19, "/dev/i2c-%d", adapter_nr);
file = open(filename, O_RDWR);
if (file < 0) {
@@ -72,8 +67,10 @@ the device supports them. Both are illustrated below.
/* res contains the read word */
}
- /* Using I2C Write, equivalent of
- i2c_smbus_write_word_data(file, reg, 0x6543) */
+ /*
+ * Using I2C Write, equivalent of
+ * i2c_smbus_write_word_data(file, reg, 0x6543)
+ */
buf[0] = reg;
buf[1] = 0x43;
buf[2] = 0x65;
@@ -140,14 +137,14 @@ ioctl(file, I2C_RDWR, struct i2c_rdwr_ioctl_data *msgset)
set in each message, overriding the values set with the above ioctl's.
ioctl(file, I2C_SMBUS, struct i2c_smbus_ioctl_data *args)
- Not meant to be called directly; instead, use the access functions
- below.
+ If possible, use the provided i2c_smbus_* methods described below instead
+ of issuing direct ioctls.
You can do plain i2c transactions by using read(2) and write(2) calls.
You do not need to pass the address byte; instead, set it through
ioctl I2C_SLAVE before you try to access the device.
-You can do SMBus level transactions (see documentation file smbus-protocol
+You can do SMBus level transactions (see documentation file smbus-protocol
for details) through the following functions:
__s32 i2c_smbus_write_quick(int file, __u8 value);
__s32 i2c_smbus_read_byte(int file);
@@ -158,7 +155,7 @@ for details) through the following functions:
__s32 i2c_smbus_write_word_data(int file, __u8 command, __u16 value);
__s32 i2c_smbus_process_call(int file, __u8 command, __u16 value);
__s32 i2c_smbus_read_block_data(int file, __u8 command, __u8 *values);
- __s32 i2c_smbus_write_block_data(int file, __u8 command, __u8 length,
+ __s32 i2c_smbus_write_block_data(int file, __u8 command, __u8 length,
__u8 *values);
All these transactions return -1 on failure; you can read errno to see
what happened. The 'write' transactions return 0 on success; the
@@ -166,10 +163,9 @@ what happened. The 'write' transactions return 0 on success; the
returns the number of values read. The block buffers need not be longer
than 32 bytes.
-The above functions are all inline functions, that resolve to calls to
-the i2c_smbus_access function, that on its turn calls a specific ioctl
-with the data in a specific format. Read the source code if you
-want to know what happens behind the screens.
+The above functions are made available by linking against the libi2c library,
+which is provided by the i2c-tools project. See:
+https://git.kernel.org/pub/scm/utils/i2c-tools/i2c-tools.git/.
Implementation details
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index c4865b08d7fb9e3b194dba2830b837fe6ab17819..8d21b9825d71764dc950a47dec4a3bc3dc102e25 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -707,7 +707,6 @@ config I2C_MPC
config I2C_MT65XX
tristate "MediaTek I2C adapter"
depends on ARCH_MEDIATEK || COMPILE_TEST
- depends on HAS_DMA
help
This selects the MediaTek(R) Integrated Inter Circuit bus driver
for MT65xx and MT81xx.
@@ -885,7 +884,6 @@ config I2C_SH7760
config I2C_SH_MOBILE
tristate "SuperH Mobile I2C Controller"
- depends on HAS_DMA
depends on ARCH_SHMOBILE || ARCH_RENESAS || COMPILE_TEST
help
If you say yes to this option, support will be included for the
@@ -1098,7 +1096,6 @@ config I2C_XLP9XX
config I2C_RCAR
tristate "Renesas R-Car I2C Controller"
- depends on HAS_DMA
depends on ARCH_RENESAS || COMPILE_TEST
select I2C_SLAVE
help
diff --git a/drivers/i2c/busses/i2c-sprd.c b/drivers/i2c/busses/i2c-sprd.c
index 25fcc3c1e32bf3d9a41fa345982039fb234dbcbd..4053259bccb8d704d9d386287086841690174844 100644
--- a/drivers/i2c/busses/i2c-sprd.c
+++ b/drivers/i2c/busses/i2c-sprd.c
@@ -86,6 +86,7 @@ struct sprd_i2c {
u32 count;
int irq;
int err;
+ bool is_suspended;
};
static void sprd_i2c_set_count(struct sprd_i2c *i2c_dev, u32 count)
@@ -283,6 +284,9 @@ static int sprd_i2c_master_xfer(struct i2c_adapter *i2c_adap,
struct sprd_i2c *i2c_dev = i2c_adap->algo_data;
int im, ret;
+ if (i2c_dev->is_suspended)
+ return -EBUSY;
+
ret = pm_runtime_get_sync(i2c_dev->dev);
if (ret < 0)
return ret;
@@ -364,13 +368,12 @@ static irqreturn_t sprd_i2c_isr_thread(int irq, void *dev_id)
struct sprd_i2c *i2c_dev = dev_id;
struct i2c_msg *msg = i2c_dev->msg;
bool ack = !(readl(i2c_dev->base + I2C_STATUS) & I2C_RX_ACK);
- u32 i2c_count = readl(i2c_dev->base + I2C_COUNT);
u32 i2c_tran;
if (msg->flags & I2C_M_RD)
i2c_tran = i2c_dev->count >= I2C_FIFO_FULL_THLD;
else
- i2c_tran = i2c_count;
+ i2c_tran = i2c_dev->count;
/*
* If we got one ACK from slave when writing data, and we did not
@@ -408,14 +411,13 @@ static irqreturn_t sprd_i2c_isr(int irq, void *dev_id)
{
struct sprd_i2c *i2c_dev = dev_id;
struct i2c_msg *msg = i2c_dev->msg;
- u32 i2c_count = readl(i2c_dev->base + I2C_COUNT);
bool ack = !(readl(i2c_dev->base + I2C_STATUS) & I2C_RX_ACK);
u32 i2c_tran;
if (msg->flags & I2C_M_RD)
i2c_tran = i2c_dev->count >= I2C_FIFO_FULL_THLD;
else
- i2c_tran = i2c_count;
+ i2c_tran = i2c_dev->count;
/*
* If we did not get one ACK from slave when writing data, then we
@@ -586,11 +588,23 @@ static int sprd_i2c_remove(struct platform_device *pdev)
static int __maybe_unused sprd_i2c_suspend_noirq(struct device *pdev)
{
+ struct sprd_i2c *i2c_dev = dev_get_drvdata(pdev);
+
+ i2c_lock_adapter(&i2c_dev->adap);
+ i2c_dev->is_suspended = true;
+ i2c_unlock_adapter(&i2c_dev->adap);
+
return pm_runtime_force_suspend(pdev);
}
static int __maybe_unused sprd_i2c_resume_noirq(struct device *pdev)
{
+ struct sprd_i2c *i2c_dev = dev_get_drvdata(pdev);
+
+ i2c_lock_adapter(&i2c_dev->adap);
+ i2c_dev->is_suspended = false;
+ i2c_unlock_adapter(&i2c_dev->adap);
+
return pm_runtime_force_resume(pdev);
}
diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index 036a03f0d0a6866001d0badd11cb9b30516ca5de..1667b6e7674f4a0439befcd544d74753e41d43f3 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -280,7 +280,7 @@ static noinline int i2cdev_ioctl_rdwr(struct i2c_client *client,
*/
if (msgs[i].flags & I2C_M_RECV_LEN) {
if (!(msgs[i].flags & I2C_M_RD) ||
- msgs[i].buf[0] < 1 ||
+ msgs[i].len < 1 || msgs[i].buf[0] < 1 ||
msgs[i].len < msgs[i].buf[0] +
I2C_SMBUS_BLOCK_MAX) {
res = -EINVAL;