[PATCH v3 2/2] i2c: mv64xxx: Fix clock resource by adding an optional bus clock
Gregory CLEMENT
gregory.clement at free-electrons.com
Fri Jan 12 02:39:56 PST 2018
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 at free-electrons.com>
---
.../devicetree/bindings/i2c/i2c-mv64xxx.txt | 20 ++++++++++++++++++++
drivers/i2c/busses/i2c-mv64xxx.c | 12 +++++++++++-
2 files changed, 31 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
index 5c30026921ae..3d76bb19492f 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
@@ -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 for the functional part
+ of the controller
+
+ - clock-names : names of used clocks, mandatory if the second clock is
+ used, the name must be "core", and "axi" (the latter is
+ only for Armada 7K/8K).
+
Examples:
i2c at 11000 {
@@ -42,3 +51,14 @@ For the Armada XP:
interrupts = <29>;
clock-frequency = <100000>;
};
+
+For the Armada 7040:
+
+ i2c at 701000 {
+ compatible = "marvell,mv78230-i2c";
+ reg = <0x701000 0x20>;
+ interrupts = <29>;
+ clock-frequency = <100000>;
+ clock-names = "core", "axi";
+ clocks = <&core_clock>, <&axi_clock>;
+ };
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index f69066266faa..cce37d8ecf41 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -135,6 +135,7 @@ struct mv64xxx_i2c_data {
u32 freq_m;
u32 freq_n;
struct clk *clk;
+ struct clk *axi_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->axi_clk = devm_clk_get(&pd->dev, "axi");
+ if (IS_ERR(drv_data->axi_clk) &&
+ PTR_ERR(drv_data->axi_clk) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+ if (!IS_ERR(drv_data->axi_clk))
+ clk_prepare_enable(drv_data->axi_clk);
+
drv_data->irq = platform_get_irq(pd, 0);
if (pdata) {
@@ -950,6 +958,7 @@ mv64xxx_i2c_probe(struct platform_device *pd)
exit_reset:
reset_control_assert(drv_data->rstc);
exit_clk:
+ clk_disable_unprepare(drv_data->axi_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->axi_clk);
clk_disable_unprepare(drv_data->clk);
return 0;
--
2.15.1
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