power/reset: at91-reset: get and use slow clock

Commit dca1a4b5ff ("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 <alexandre.belloni@free-electrons.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
This commit is contained in:
Alexandre Belloni 2015-08-11 11:12:48 +02:00 committed by Sebastian Reichel
parent 6e64180a7c
commit 2b2c6148fe

View file

@ -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
@ -205,9 +207,21 @@ static int __init 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;
ret = register_restart_handler(&at91_restart_nb);
if (ret)
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) {
clk_disable_unprepare(sclk);
return ret;
}
at91_reset_status(pdev);
@ -217,6 +231,7 @@ static int __init at91_reset_probe(struct platform_device *pdev)
static int __exit at91_reset_remove(struct platform_device *pdev)
{
unregister_restart_handler(&at91_restart_nb);
clk_disable_unprepare(sclk);
return 0;
}