misc: atmel_tclib: get and use slow clock
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 timer counters.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
diff --git a/drivers/pwm/pwm-atmel-tcb.c b/drivers/pwm/pwm-atmel-tcb.c
index 6da01b3..75db585 100644
--- a/drivers/pwm/pwm-atmel-tcb.c
+++ b/drivers/pwm/pwm-atmel-tcb.c
@@ -305,7 +305,7 @@
*/
if (i == 5) {
i = slowclk;
- rate = 32768;
+ rate = clk_get_rate(tc->slow_clk);
min = div_u64(NSEC_PER_SEC, rate);
max = min << tc->tcb_config->counter_width;
@@ -387,9 +387,9 @@
tcbpwm = devm_kzalloc(&pdev->dev, sizeof(*tcbpwm), GFP_KERNEL);
if (tcbpwm == NULL) {
- atmel_tc_free(tc);
+ err = -ENOMEM;
dev_err(&pdev->dev, "failed to allocate memory\n");
- return -ENOMEM;
+ goto err_free_tc;
}
tcbpwm->chip.dev = &pdev->dev;
@@ -400,17 +400,27 @@
tcbpwm->chip.npwm = NPWM;
tcbpwm->tc = tc;
+ err = clk_prepare_enable(tc->slow_clk);
+ if (err)
+ goto err_free_tc;
+
spin_lock_init(&tcbpwm->lock);
err = pwmchip_add(&tcbpwm->chip);
- if (err < 0) {
- atmel_tc_free(tc);
- return err;
- }
+ if (err < 0)
+ goto err_disable_clk;
platform_set_drvdata(pdev, tcbpwm);
return 0;
+
+err_disable_clk:
+ clk_disable_unprepare(tcbpwm->tc->slow_clk);
+
+err_free_tc:
+ atmel_tc_free(tc);
+
+ return err;
}
static int atmel_tcb_pwm_remove(struct platform_device *pdev)
@@ -418,6 +428,8 @@
struct atmel_tcb_pwm_chip *tcbpwm = platform_get_drvdata(pdev);
int err;
+ clk_disable_unprepare(tcbpwm->tc->slow_clk);
+
err = pwmchip_remove(&tcbpwm->chip);
if (err < 0)
return err;