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path: root/drivers/i2c/i2c-core-base.c
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Diffstat (limited to 'drivers/i2c/i2c-core-base.c')
-rw-r--r--drivers/i2c/i2c-core-base.c212
1 files changed, 96 insertions, 116 deletions
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index f7829a74140c..5a00bf443d06 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -27,7 +27,7 @@
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/errno.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/i2c-smbus.h>
#include <linux/idr.h>
@@ -134,52 +134,22 @@ static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
/* i2c bus recovery routines */
static int get_scl_gpio_value(struct i2c_adapter *adap)
{
- return gpio_get_value(adap->bus_recovery_info->scl_gpio);
+ return gpiod_get_value_cansleep(adap->bus_recovery_info->scl_gpiod);
}
static void set_scl_gpio_value(struct i2c_adapter *adap, int val)
{
- gpio_set_value(adap->bus_recovery_info->scl_gpio, val);
+ gpiod_set_value_cansleep(adap->bus_recovery_info->scl_gpiod, val);
}
static int get_sda_gpio_value(struct i2c_adapter *adap)
{
- return gpio_get_value(adap->bus_recovery_info->sda_gpio);
+ return gpiod_get_value_cansleep(adap->bus_recovery_info->sda_gpiod);
}
-static int i2c_get_gpios_for_recovery(struct i2c_adapter *adap)
+static void set_sda_gpio_value(struct i2c_adapter *adap, int val)
{
- struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
- struct device *dev = &adap->dev;
- int ret = 0;
-
- ret = gpio_request_one(bri->scl_gpio, GPIOF_OPEN_DRAIN |
- GPIOF_OUT_INIT_HIGH, "i2c-scl");
- if (ret) {
- dev_warn(dev, "Can't get SCL gpio: %d\n", bri->scl_gpio);
- return ret;
- }
-
- if (bri->get_sda) {
- if (gpio_request_one(bri->sda_gpio, GPIOF_IN, "i2c-sda")) {
- /* work without SDA polling */
- dev_warn(dev, "Can't get SDA gpio: %d. Not using SDA polling\n",
- bri->sda_gpio);
- bri->get_sda = NULL;
- }
- }
-
- return ret;
-}
-
-static void i2c_put_gpios_for_recovery(struct i2c_adapter *adap)
-{
- struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
-
- if (bri->get_sda)
- gpio_free(bri->sda_gpio);
-
- gpio_free(bri->scl_gpio);
+ gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val);
}
/*
@@ -190,7 +160,7 @@ static void i2c_put_gpios_for_recovery(struct i2c_adapter *adap)
#define RECOVERY_NDELAY 5000
#define RECOVERY_CLK_CNT 9
-static int i2c_generic_recovery(struct i2c_adapter *adap)
+int i2c_generic_scl_recovery(struct i2c_adapter *adap)
{
struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
int i = 0, val = 1, ret = 0;
@@ -199,6 +169,8 @@ static int i2c_generic_recovery(struct i2c_adapter *adap)
bri->prepare_recovery(adap);
bri->set_scl(adap, val);
+ if (bri->set_sda)
+ bri->set_sda(adap, 1);
ndelay(RECOVERY_NDELAY);
/*
@@ -227,33 +199,25 @@ static int i2c_generic_recovery(struct i2c_adapter *adap)
if (bri->get_sda && !bri->get_sda(adap))
ret = -EBUSY;
+ /* If all went well, send STOP for a sane bus state. */
+ if (ret == 0 && bri->set_sda) {
+ bri->set_scl(adap, 0);
+ ndelay(RECOVERY_NDELAY / 2);
+ bri->set_sda(adap, 0);
+ ndelay(RECOVERY_NDELAY / 2);
+ bri->set_scl(adap, 1);
+ ndelay(RECOVERY_NDELAY / 2);
+ bri->set_sda(adap, 1);
+ ndelay(RECOVERY_NDELAY / 2);
+ }
+
if (bri->unprepare_recovery)
bri->unprepare_recovery(adap);
return ret;
}
-
-int i2c_generic_scl_recovery(struct i2c_adapter *adap)
-{
- return i2c_generic_recovery(adap);
-}
EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery);
-int i2c_generic_gpio_recovery(struct i2c_adapter *adap)
-{
- int ret;
-
- ret = i2c_get_gpios_for_recovery(adap);
- if (ret)
- return ret;
-
- ret = i2c_generic_recovery(adap);
- i2c_put_gpios_for_recovery(adap);
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(i2c_generic_gpio_recovery);
-
int i2c_recover_bus(struct i2c_adapter *adap)
{
if (!adap->bus_recovery_info)
@@ -277,21 +241,19 @@ static void i2c_init_recovery(struct i2c_adapter *adap)
goto err;
}
- /* Generic GPIO recovery */
- if (bri->recover_bus == i2c_generic_gpio_recovery) {
- if (!gpio_is_valid(bri->scl_gpio)) {
- err_str = "invalid SCL gpio";
- goto err;
- }
-
- if (gpio_is_valid(bri->sda_gpio))
- bri->get_sda = get_sda_gpio_value;
- else
- bri->get_sda = NULL;
-
+ if (bri->scl_gpiod && bri->recover_bus == i2c_generic_scl_recovery) {
bri->get_scl = get_scl_gpio_value;
bri->set_scl = set_scl_gpio_value;
- } else if (bri->recover_bus == i2c_generic_scl_recovery) {
+ if (bri->sda_gpiod) {
+ bri->get_sda = get_sda_gpio_value;
+ /* FIXME: add proper flag instead of '0' once available */
+ if (gpiod_get_direction(bri->sda_gpiod) == 0)
+ bri->set_sda = set_sda_gpio_value;
+ }
+ return;
+ }
+
+ if (bri->recover_bus == i2c_generic_scl_recovery) {
/* Generic SCL recovery */
if (!bri->set_scl || !bri->get_scl) {
err_str = "no {get|set}_scl() found";
@@ -1976,63 +1938,35 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
EXPORT_SYMBOL(i2c_transfer);
/**
- * i2c_master_send - issue a single I2C message in master transmit mode
- * @client: Handle to slave device
- * @buf: Data that will be written to the slave
- * @count: How many bytes to write, must be less than 64k since msg.len is u16
- *
- * Returns negative errno, or else the number of bytes written.
- */
-int i2c_master_send(const struct i2c_client *client, const char *buf, int count)
-{
- int ret;
- struct i2c_adapter *adap = client->adapter;
- struct i2c_msg msg;
-
- msg.addr = client->addr;
- msg.flags = client->flags & I2C_M_TEN;
- msg.len = count;
- msg.buf = (char *)buf;
-
- ret = i2c_transfer(adap, &msg, 1);
-
- /*
- * If everything went ok (i.e. 1 msg transmitted), return #bytes
- * transmitted, else error code.
- */
- return (ret == 1) ? count : ret;
-}
-EXPORT_SYMBOL(i2c_master_send);
-
-/**
- * i2c_master_recv - issue a single I2C message in master receive mode
+ * i2c_transfer_buffer_flags - issue a single I2C message transferring data
+ * to/from a buffer
* @client: Handle to slave device
- * @buf: Where to store data read from slave
- * @count: How many bytes to read, must be less than 64k since msg.len is u16
+ * @buf: Where the data is stored
+ * @count: How many bytes to transfer, must be less than 64k since msg.len is u16
+ * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads
*
- * Returns negative errno, or else the number of bytes read.
+ * Returns negative errno, or else the number of bytes transferred.
*/
-int i2c_master_recv(const struct i2c_client *client, char *buf, int count)
+int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf,
+ int count, u16 flags)
{
- struct i2c_adapter *adap = client->adapter;
- struct i2c_msg msg;
int ret;
+ struct i2c_msg msg = {
+ .addr = client->addr,
+ .flags = flags | (client->flags & I2C_M_TEN),
+ .len = count,
+ .buf = buf,
+ };
- msg.addr = client->addr;
- msg.flags = client->flags & I2C_M_TEN;
- msg.flags |= I2C_M_RD;
- msg.len = count;
- msg.buf = buf;
-
- ret = i2c_transfer(adap, &msg, 1);
+ ret = i2c_transfer(client->adapter, &msg, 1);
/*
- * If everything went ok (i.e. 1 msg received), return #bytes received,
- * else error code.
+ * If everything went ok (i.e. 1 msg transferred), return #bytes
+ * transferred, else error code.
*/
return (ret == 1) ? count : ret;
}
-EXPORT_SYMBOL(i2c_master_recv);
+EXPORT_SYMBOL(i2c_transfer_buffer_flags);
/* ----------------------------------------------------
* the i2c address scanning function
@@ -2265,6 +2199,52 @@ void i2c_put_adapter(struct i2c_adapter *adap)
}
EXPORT_SYMBOL(i2c_put_adapter);
+/**
+ * i2c_get_dma_safe_msg_buf() - get a DMA safe buffer for the given i2c_msg
+ * @msg: the message to be checked
+ * @threshold: the minimum number of bytes for which using DMA makes sense
+ *
+ * Return: NULL if a DMA safe buffer was not obtained. Use msg->buf with PIO.
+ * Or a valid pointer to be used with DMA. After use, release it by
+ * calling i2c_release_dma_safe_msg_buf().
+ *
+ * This function must only be called from process context!
+ */
+u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold)
+{
+ if (msg->len < threshold)
+ return NULL;
+
+ if (msg->flags & I2C_M_DMA_SAFE)
+ return msg->buf;
+
+ pr_debug("using bounce buffer for addr=0x%02x, len=%d\n",
+ msg->addr, msg->len);
+
+ if (msg->flags & I2C_M_RD)
+ return kzalloc(msg->len, GFP_KERNEL);
+ else
+ return kmemdup(msg->buf, msg->len, GFP_KERNEL);
+}
+EXPORT_SYMBOL_GPL(i2c_get_dma_safe_msg_buf);
+
+/**
+ * i2c_release_dma_safe_msg_buf - release DMA safe buffer and sync with i2c_msg
+ * @msg: the message to be synced with
+ * @buf: the buffer obtained from i2c_get_dma_safe_msg_buf(). May be NULL.
+ */
+void i2c_release_dma_safe_msg_buf(struct i2c_msg *msg, u8 *buf)
+{
+ if (!buf || buf == msg->buf)
+ return;
+
+ if (msg->flags & I2C_M_RD)
+ memcpy(msg->buf, buf, msg->len);
+
+ kfree(buf);
+}
+EXPORT_SYMBOL_GPL(i2c_release_dma_safe_msg_buf);
+
MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
MODULE_DESCRIPTION("I2C-Bus main module");
MODULE_LICENSE("GPL");