misc: atmel_tclib: 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 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>
This commit is contained in:
Boris Brezillon 2015-08-16 11:23:46 +02:00 committed by Alexandre Belloni
parent eed9fb9df4
commit 7d8d05d114
4 changed files with 34 additions and 9 deletions

View File

@ -193,10 +193,17 @@ static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
struct clk *t2_clk = tc->clk[2];
int irq = tc->irq[2];
/* try to enable t2 clk to avoid future errors in mode change */
ret = clk_prepare_enable(t2_clk);
ret = clk_prepare_enable(tc->slow_clk);
if (ret)
return ret;
/* try to enable t2 clk to avoid future errors in mode change */
ret = clk_prepare_enable(t2_clk);
if (ret) {
clk_disable_unprepare(tc->slow_clk);
return ret;
}
clk_disable(t2_clk);
clkevt.regs = tc->regs;
@ -209,6 +216,7 @@ static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
ret = request_irq(irq, ch2_irq, IRQF_TIMER, "tc_clkevt", &clkevt);
if (ret) {
clk_unprepare(t2_clk);
clk_disable_unprepare(tc->slow_clk);
return ret;
}

View File

@ -125,6 +125,10 @@ static int __init tc_probe(struct platform_device *pdev)
if (IS_ERR(clk))
return PTR_ERR(clk);
tc->slow_clk = devm_clk_get(&pdev->dev, "slow_clk");
if (IS_ERR(tc->slow_clk))
return PTR_ERR(tc->slow_clk);
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
tc->regs = devm_ioremap_resource(&pdev->dev, r);
if (IS_ERR(tc->regs))

View File

@ -305,7 +305,7 @@ static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
*/
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 @@ static int atmel_tcb_pwm_probe(struct platform_device *pdev)
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 @@ static int atmel_tcb_pwm_probe(struct platform_device *pdev)
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 @@ static int atmel_tcb_pwm_remove(struct platform_device *pdev)
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;

View File

@ -67,6 +67,7 @@ struct atmel_tc {
const struct atmel_tcb_config *tcb_config;
int irq[3];
struct clk *clk[3];
struct clk *slow_clk;
struct list_head node;
bool allocated;
};