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authorLinus Torvalds <torvalds@linux-foundation.org>2020-01-11 15:40:43 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-01-11 15:40:43 -0800
commit6327edceb62bc4c91195e2dc6d5574a53005cb5a (patch)
tree9265680070e5bdaf81069de7bafa3d86dd0729a1
parent606e9ad20094f6d500166881d301f31a51bc8aa7 (diff)
parentcf8ce8b80f8bf9669f6ec4e71e16668430febdac (diff)
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Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c fixes from Wolfram Sang: "Two driver bugfixes, a documentation fix, and a removal of a spec violation for the bus recovery algorithm in the core" * 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: i2c: fix bus recovery stop mode timing i2c: bcm2835: Store pointer to bus clock dt-bindings: i2c: at91: fix i2c-sda-hold-time-ns documentation for sam9x60 i2c: at91: fix clk_offset for sam9x60
-rw-r--r--Documentation/devicetree/bindings/i2c/i2c-at91.txt6
-rw-r--r--drivers/i2c/busses/i2c-at91-core.c2
-rw-r--r--drivers/i2c/busses/i2c-bcm2835.c17
-rw-r--r--drivers/i2c/i2c-core-base.c13
4 files changed, 23 insertions, 15 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-at91.txt b/Documentation/devicetree/bindings/i2c/i2c-at91.txt
index 2210f4359c45..8347b1e7c080 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-at91.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-at91.txt
@@ -18,8 +18,10 @@ Optional properties:
- dma-names: should contain "tx" and "rx".
- atmel,fifo-size: maximum number of data the RX and TX FIFOs can store for FIFO
capable I2C controllers.
-- i2c-sda-hold-time-ns: TWD hold time, only available for "atmel,sama5d4-i2c"
- and "atmel,sama5d2-i2c".
+- i2c-sda-hold-time-ns: TWD hold time, only available for:
+ "atmel,sama5d4-i2c",
+ "atmel,sama5d2-i2c",
+ "microchip,sam9x60-i2c".
- Child nodes conforming to i2c bus binding
Examples :
diff --git a/drivers/i2c/busses/i2c-at91-core.c b/drivers/i2c/busses/i2c-at91-core.c
index e13af4874976..5137e6297022 100644
--- a/drivers/i2c/busses/i2c-at91-core.c
+++ b/drivers/i2c/busses/i2c-at91-core.c
@@ -174,7 +174,7 @@ static struct at91_twi_pdata sama5d2_config = {
static struct at91_twi_pdata sam9x60_config = {
.clk_max_div = 7,
- .clk_offset = 4,
+ .clk_offset = 3,
.has_unre_flag = true,
.has_alt_cmd = true,
.has_hold_field = true,
diff --git a/drivers/i2c/busses/i2c-bcm2835.c b/drivers/i2c/busses/i2c-bcm2835.c
index e01b2b57e724..5ab901ad615d 100644
--- a/drivers/i2c/busses/i2c-bcm2835.c
+++ b/drivers/i2c/busses/i2c-bcm2835.c
@@ -58,6 +58,7 @@ struct bcm2835_i2c_dev {
struct i2c_adapter adapter;
struct completion completion;
struct i2c_msg *curr_msg;
+ struct clk *bus_clk;
int num_msgs;
u32 msg_err;
u8 *msg_buf;
@@ -404,7 +405,6 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
struct resource *mem, *irq;
int ret;
struct i2c_adapter *adap;
- struct clk *bus_clk;
struct clk *mclk;
u32 bus_clk_rate;
@@ -427,11 +427,11 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
return PTR_ERR(mclk);
}
- bus_clk = bcm2835_i2c_register_div(&pdev->dev, mclk, i2c_dev);
+ i2c_dev->bus_clk = bcm2835_i2c_register_div(&pdev->dev, mclk, i2c_dev);
- if (IS_ERR(bus_clk)) {
+ if (IS_ERR(i2c_dev->bus_clk)) {
dev_err(&pdev->dev, "Could not register clock\n");
- return PTR_ERR(bus_clk);
+ return PTR_ERR(i2c_dev->bus_clk);
}
ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
@@ -442,13 +442,13 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
bus_clk_rate = 100000;
}
- ret = clk_set_rate_exclusive(bus_clk, bus_clk_rate);
+ ret = clk_set_rate_exclusive(i2c_dev->bus_clk, bus_clk_rate);
if (ret < 0) {
dev_err(&pdev->dev, "Could not set clock frequency\n");
return ret;
}
- ret = clk_prepare_enable(bus_clk);
+ ret = clk_prepare_enable(i2c_dev->bus_clk);
if (ret) {
dev_err(&pdev->dev, "Couldn't prepare clock");
return ret;
@@ -491,10 +491,9 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
static int bcm2835_i2c_remove(struct platform_device *pdev)
{
struct bcm2835_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
- struct clk *bus_clk = devm_clk_get(i2c_dev->dev, "div");
- clk_rate_exclusive_put(bus_clk);
- clk_disable_unprepare(bus_clk);
+ clk_rate_exclusive_put(i2c_dev->bus_clk);
+ clk_disable_unprepare(i2c_dev->bus_clk);
free_irq(i2c_dev->irq, i2c_dev);
i2c_del_adapter(&i2c_dev->adapter);
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 9f8dcd3f8385..35b209797d7b 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -186,10 +186,11 @@ int i2c_generic_scl_recovery(struct i2c_adapter *adap)
* If we can set SDA, we will always create a STOP to ensure additional
* pulses will do no harm. This is achieved by letting SDA follow SCL
* half a cycle later. Check the 'incomplete_write_byte' fault injector
- * for details.
+ * for details. Note that we must honour tsu:sto, 4us, but lets use 5us
+ * here for simplicity.
*/
bri->set_scl(adap, scl);
- ndelay(RECOVERY_NDELAY / 2);
+ ndelay(RECOVERY_NDELAY);
if (bri->set_sda)
bri->set_sda(adap, scl);
ndelay(RECOVERY_NDELAY / 2);
@@ -211,7 +212,13 @@ int i2c_generic_scl_recovery(struct i2c_adapter *adap)
scl = !scl;
bri->set_scl(adap, scl);
/* Creating STOP again, see above */
- ndelay(RECOVERY_NDELAY / 2);
+ if (scl) {
+ /* Honour minimum tsu:sto */
+ ndelay(RECOVERY_NDELAY);
+ } else {
+ /* Honour minimum tf and thd:dat */
+ ndelay(RECOVERY_NDELAY / 2);
+ }
if (bri->set_sda)
bri->set_sda(adap, scl);
ndelay(RECOVERY_NDELAY / 2);