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| author | Gerhard Sittig <gsi@denx.de> | 2013-08-23 18:01:44 +0200 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2013-08-28 10:48:44 +0200 |
| commit | b3bfce2bc205ff4fdb4ec0b048513557cef459cf (patch) | |
| tree | 5b006b07d78f10705e78e14911f3791de42cf0c6 /drivers/i2c/busses | |
| parent | 498c0146213aa5fbca3b63a6525e91c606c20c5e (diff) | |
| download | lwn-b3bfce2bc205ff4fdb4ec0b048513557cef459cf.tar.gz lwn-b3bfce2bc205ff4fdb4ec0b048513557cef459cf.zip | |
i2c: mpc: cleanup clock API use
make the MPC I2C driver get, prepare and enable the gated clock item for
register access during probe; disable and unprepare the clock upon
remove(), put is done by the devm approach; hold a reference to the
clock over the period of use
clock lookup is non-fatal in this implementation as not all platforms
may provide clock specs in their device tree, but failure to enable a
clock when specified is considered fatal
Signed-off-by: Gerhard Sittig <gsi@denx.de>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c/busses')
| -rw-r--r-- | drivers/i2c/busses/i2c-mpc.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c index f4060939e959..b80c76888cab 100644 --- a/drivers/i2c/busses/i2c-mpc.c +++ b/drivers/i2c/busses/i2c-mpc.c @@ -20,6 +20,7 @@ #include <linux/of_platform.h> #include <linux/slab.h> +#include <linux/clk.h> #include <linux/io.h> #include <linux/fsl_devices.h> #include <linux/i2c.h> @@ -66,6 +67,7 @@ struct mpc_i2c { #ifdef CONFIG_PM_SLEEP u8 fdr, dfsrr; #endif + struct clk *clk_per; }; struct mpc_i2c_divider { @@ -622,6 +624,8 @@ static int fsl_i2c_probe(struct platform_device *op) int result = 0; int plen; struct resource res; + struct clk *clk; + int err; match = of_match_device(mpc_i2c_of_match, &op->dev); if (!match) @@ -652,6 +656,21 @@ static int fsl_i2c_probe(struct platform_device *op) } } + /* + * enable clock for the I2C peripheral (non fatal), + * keep a reference upon successful allocation + */ + clk = devm_clk_get(&op->dev, NULL); + if (!IS_ERR(clk)) { + err = clk_prepare_enable(clk); + if (err) { + dev_err(&op->dev, "failed to enable clock\n"); + goto fail_request; + } else { + i2c->clk_per = clk; + } + } + if (of_get_property(op->dev.of_node, "fsl,preserve-clocking", NULL)) { clock = MPC_I2C_CLOCK_PRESERVE; } else { @@ -697,6 +716,8 @@ static int fsl_i2c_probe(struct platform_device *op) return result; fail_add: + if (i2c->clk_per) + clk_disable_unprepare(i2c->clk_per); free_irq(i2c->irq, i2c); fail_request: irq_dispose_mapping(i2c->irq); @@ -712,6 +733,9 @@ static int fsl_i2c_remove(struct platform_device *op) i2c_del_adapter(&i2c->adap); + if (i2c->clk_per) + clk_disable_unprepare(i2c->clk_per); + if (i2c->irq) free_irq(i2c->irq, i2c); |