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Subject[PATCH] i2c-ocores: add common clock support
Date
Allow bus clock specification as a common clock handle. This makes this
controller easier to use in a setup based on common clock framework.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
.../devicetree/bindings/i2c/i2c-ocores.txt | 4 ++-
drivers/i2c/busses/i2c-ocores.c | 38 ++++++++++++++++++++--
2 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/i2c/i2c-ocores.txt b/Documentation/devicetree/bindings/i2c/i2c-ocores.txt
index 1637c29..4b4c5a3 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-ocores.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-ocores.txt
@@ -4,7 +4,9 @@ Required properties:
- compatible : "opencores,i2c-ocores" or "aeroflexgaisler,i2cmst"
- reg : bus address start and address range size of device
- interrupts : interrupt number
-- clock-frequency : frequency of bus clock in Hz
+- clk : handle to bus clock (mutually exclusive with
+ clock-frequency)
+- clock-frequency : frequency of bus clock in Hz (mutually exclusive with clk)
- #address-cells : should be <1>
- #size-cells : should be <0>

diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
index 7249b5b..f97c5c8 100644
--- a/drivers/i2c/busses/i2c-ocores.c
+++ b/drivers/i2c/busses/i2c-ocores.c
@@ -12,6 +12,7 @@
* kind, whether express or implied.
*/

+#include <linux/clk.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
@@ -36,6 +37,7 @@ struct ocores_i2c {
int nmsgs;
int state; /* see STATE_ */
int clock_khz;
+ struct clk *clk;
void (*setreg)(struct ocores_i2c *i2c, int reg, u8 value);
u8 (*getreg)(struct ocores_i2c *i2c, int reg);
};
@@ -320,9 +322,23 @@ static int ocores_i2c_of_probe(struct platform_device *pdev,
}

if (of_property_read_u32(np, "clock-frequency", &val)) {
- dev_err(&pdev->dev,
- "Missing required parameter 'clock-frequency'\n");
- return -ENODEV;
+ struct clk *clk = devm_clk_get(&pdev->dev, NULL);
+
+ if (!IS_ERR(clk)) {
+ int ret = clk_prepare_enable(clk);
+
+ if (ret) {
+ dev_err(&pdev->dev,
+ "clk_prepare_enable failed: %d\n", ret);
+ return ret;
+ }
+ i2c->clk = clk;
+ val = clk_get_rate(clk);
+ } else {
+ dev_err(&pdev->dev,
+ "Missing required parameter 'clock-frequency'\n");
+ return -ENODEV;
+ }
}
i2c->clock_khz = val / 1000;

@@ -446,6 +462,9 @@ static int ocores_i2c_remove(struct platform_device *pdev)
/* remove adapter & data */
i2c_del_adapter(&i2c->adap);

+ if (i2c->clk)
+ clk_disable_unprepare(i2c->clk);
+
return 0;
}

@@ -458,6 +477,9 @@ static int ocores_i2c_suspend(struct device *dev)
/* make sure the device is disabled */
oc_setreg(i2c, OCI2C_CONTROL, ctrl & ~(OCI2C_CTRL_EN|OCI2C_CTRL_IEN));

+ if (i2c->clk)
+ clk_disable_unprepare(i2c->clk);
+
return 0;
}

@@ -465,6 +487,16 @@ static int ocores_i2c_resume(struct device *dev)
{
struct ocores_i2c *i2c = dev_get_drvdata(dev);

+ if (i2c->clk) {
+ int ret = clk_prepare_enable(i2c->clk);
+
+ if (ret) {
+ dev_err(&pdev->dev,
+ "clk_prepare_enable failed: %d\n", ret);
+ return ret;
+ }
+ }
+
ocores_init(i2c);

return 0;
--
1.8.1.4


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