2023-03-02 09:13:04

by Uwe Kleine-König

Subject: [PATCH] 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 <[email protected]>
---
drivers/misc/sram.c | 17 +++++------------
drivers/misc/sram.h | 1 -
2 files changed, 5 insertions(+), 13 deletions(-)

diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c
index f0e7f02605eb..dec92580a42c 100644
--- 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 d2058d8c8f1d..397205b8bf6f 100644
--- 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;

base-commit: c0927a7a5391f7d8e593e5e50ead7505a23cadf9
--
2.39.1

2023-03-06 12:01:47

by Philipp Zabel

Subject: Re: [PATCH] misc: sram: Improve and simplify clk handling

On Thu, Mar 02, 2023 at 10:12:51AM +0100, Uwe Kleine-K?nig wrote:
> 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-K?nig <[email protected]>

Reviewed-by: Philipp Zabel <[email protected]>

regards
Philipp