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i2c: mv64xxx: Fix clock resource by adding an optional bus clock 

On Armada 7K/8K we need to explicitly enable the bus clock. The bus clock
is optional because not all the SoCs need them but at least for Armada
7K/8K it is actually mandatory.

The binding documentation is updating accordingly.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
hifive-unleashed-5.1
Gregory CLEMENT 2018-01-16 17:35:39 +01:00 committed by Wolfram Sang
parent a9e94bb80e
commit 1534156e99
2 changed files with 31 additions and 1 deletions
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20
Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
View File

@ -25,6 +25,15 @@ default frequency is 100kHz
whenever you're using the "allwinner,sun6i-a31-i2c"
compatible.
- clocks: : pointers to the reference clocks for this device, the
first one is the one used for the clock on the i2c bus,
the second one is the clock used to acces the registers
of the controller
- clock-names : names of used clocks, mandatory if the second clock is
used, the name must be "core", and "reg" (the latter is
only for Armada 7K/8K).
Examples:
i2c@11000 {
@ -42,3 +51,14 @@ For the Armada XP:
interrupts = <29>;
clock-frequency = <100000>;
};
For the Armada 7040:
i2c@701000 {
compatible = "marvell,mv78230-i2c";
reg = <0x701000 0x20>;
interrupts = <29>;
clock-frequency = <100000>;
clock-names = "core", "reg";
clocks = <&core_clock>, <&reg_clock>;
};

12
drivers/i2c/busses/i2c-mv64xxx.c
View File

@ -135,6 +135,7 @@ struct mv64xxx_i2c_data {
u32 freq_m;
u32 freq_n;
struct clk *clk;
struct clk *reg_clk;
wait_queue_head_t waitq;
spinlock_t lock;
struct i2c_msg *msg;
@ -894,13 +895,20 @@ mv64xxx_i2c_probe(struct platform_device *pd)
init_waitqueue_head(&drv_data->waitq);
spin_lock_init(&drv_data->lock);
/* Not all platforms have a clk */
/* Not all platforms have clocks */
drv_data->clk = devm_clk_get(&pd->dev, NULL);
if (IS_ERR(drv_data->clk) && PTR_ERR(drv_data->clk) == -EPROBE_DEFER)
return -EPROBE_DEFER;
if (!IS_ERR(drv_data->clk))
clk_prepare_enable(drv_data->clk);
drv_data->reg_clk = devm_clk_get(&pd->dev, "reg");
if (IS_ERR(drv_data->reg_clk) &&
PTR_ERR(drv_data->reg_clk) == -EPROBE_DEFER)
return -EPROBE_DEFER;
if (!IS_ERR(drv_data->reg_clk))
clk_prepare_enable(drv_data->reg_clk);
drv_data->irq = platform_get_irq(pd, 0);
if (pdata) {
@ -950,6 +958,7 @@ exit_free_irq:
exit_reset:
reset_control_assert(drv_data->rstc);
exit_clk:
clk_disable_unprepare(drv_data->reg_clk);
clk_disable_unprepare(drv_data->clk);
return rc;
@ -963,6 +972,7 @@ mv64xxx_i2c_remove(struct platform_device *dev)
i2c_del_adapter(&drv_data->adapter);
free_irq(drv_data->irq, drv_data);
reset_control_assert(drv_data->rstc);
clk_disable_unprepare(drv_data->reg_clk);
clk_disable_unprepare(drv_data->clk);
return 0;