misc: sram: Improve and simplify clk handling

The current code tries to get an associated clk, ignores any errors in the
process and if there is a clock enables it unconditionally for the whole
lifetime of the sram device.

Instead use an "optional" variant of devm_clk_get() which handles the case
where no clk is needed for the sram device and do proper error handling
for the remaining error cases. Also use an "enabled" variant of
devm_clk_get() to simplify. With that .probe() is the only function using
struct sram_dev::clk, so it can be replaced by a local variable.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Link: https://lore.kernel.org/r/20230302091251.1852454-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c
index f0e7f02..dec9258 100644 (file)
--- a/drivers/misc/sram.c
+++ b/drivers/misc/sram.c
@@ -381,6 +381,7 @@ static int sram_probe(struct platform_device *pdev)
        struct sram_dev *sram;
        int ret;
        struct resource *res;
+       struct clk *clk;
 
        config = of_device_get_match_data(&pdev->dev);
 
@@ -409,16 +410,14 @@ static int sram_probe(struct platform_device *pdev)
                        return PTR_ERR(sram->pool);
        }
 
-       sram->clk = devm_clk_get(sram->dev, NULL);
-       if (IS_ERR(sram->clk))
-               sram->clk = NULL;
-       else
-               clk_prepare_enable(sram->clk);
+       clk = devm_clk_get_optional_enabled(sram->dev, NULL);
+       if (IS_ERR(clk))
+               return PTR_ERR(clk);
 
        ret = sram_reserve_regions(sram,
                        platform_get_resource(pdev, IORESOURCE_MEM, 0));
        if (ret)
-               goto err_disable_clk;
+               return ret;
 
        platform_set_drvdata(pdev, sram);
 
@@ -436,9 +435,6 @@ static int sram_probe(struct platform_device *pdev)
 
 err_free_partitions:
        sram_free_partitions(sram);
-err_disable_clk:
-       if (sram->clk)
-               clk_disable_unprepare(sram->clk);
 
        return ret;
 }
@@ -452,9 +448,6 @@ static int sram_remove(struct platform_device *pdev)
        if (sram->pool && gen_pool_avail(sram->pool) < gen_pool_size(sram->pool))
                dev_err(sram->dev, "removed while SRAM allocated\n");
 
-       if (sram->clk)
-               clk_disable_unprepare(sram->clk);
-
        return 0;
 }
 

diff --git a/drivers/misc/sram.h b/drivers/misc/sram.h
index d2058d8..397205b 100644 (file)
--- a/drivers/misc/sram.h
+++ b/drivers/misc/sram.h
@@ -27,7 +27,6 @@ struct sram_dev {
        bool no_memory_wc;
 
        struct gen_pool *pool;
-       struct clk *clk;
 
        struct sram_partition *partition;
        u32 partitions;