Commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system
hang") added a workaround for the slow clock as it is not properly handled
by its users.

Get and use the slow clock as it is necessary for the at91 reset
controller.

Signed-off-by: Alexandre Belloni <[email protected]>
---
Cc: Sebastian Reichel <[email protected]>
Cc: Dmitry Eremin-Solenikov <[email protected]>
Cc: [email protected]
 drivers/power/reset/at91-reset.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c
index 3225c8590ed0..19fdd4c107dc 100644
--- a/drivers/power/reset/at91-reset.c
+++ b/drivers/power/reset/at91-reset.c
@@ -11,6 +11,7 @@
  * warranty of any kind, whether express or implied.
  */
 
+#include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
@@ -46,6 +47,7 @@ enum reset_type {
 };
 
 static void __iomem *at91_ramc_base[2], *at91_rstc_base;
+static struct clk *sclk;
 
 /*
 * unless the SDRAM is cleanly shutdown before we hit the
@@ -193,9 +195,21 @@ static int at91_reset_probe(struct platform_device *pdev)
        match = of_match_node(at91_reset_of_match, pdev->dev.of_node);
        at91_restart_nb.notifier_call = match->data;
 
+       sclk = devm_clk_get(&pdev->dev, NULL);
+       if (IS_ERR(sclk))
+               return PTR_ERR(sclk);
+
+       ret = clk_prepare_enable(sclk);
+       if (ret) {
+               dev_err(&pdev->dev, "Could not enable slow clock\n");
+               return ret;
+       }
+
        ret = register_restart_handler(&at91_restart_nb);
-       if (ret)
+       if (ret) {
+               clk_disable_unprepare(sclk);
                return ret;
+       }
 
        at91_reset_status(pdev);
 
-- 
2.1.4

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