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Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

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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
This commit is contained in:
Linus Torvalds 2020-01-11 15:40:43 -08:00
commit 6327edceb6
4 changed files with 23 additions and 15 deletions
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6
Documentation/devicetree/bindings/i2c/i2c-at91.txt
View File

@ -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 :

2
drivers/i2c/busses/i2c-at91-core.c
View File

@ -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,

17
drivers/i2c/busses/i2c-bcm2835.c
View File

@ -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);

13
drivers/i2c/i2c-core-base.c
View File

@ -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);