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Commit 7d8d05d1 authored by Boris Brezillon's avatar Boris Brezillon Committed by Alexandre Belloni
Browse files

misc: atmel_tclib: get and use slow clock 



Commit dca1a4b5 ("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: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: default avatarThierry Reding <thierry.reding@gmail.com>
parent eed9fb9d

drivers/clocksource/tcb_clksrc.c

+9 −1
Original line number Diff line number Diff line
@@ -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];



	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)

	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;

	}

drivers/misc/atmel_tclib.c

+4 −0
Original line number Diff line number Diff line
@@ -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))

drivers/pwm/pwm-atmel-tcb.c

+19 −7
Original line number Diff line number Diff line
@@ -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;

include/linux/atmel_tc.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

};