From 216ab8f155fba659e06df240862cf59acb8b7be5 Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Sun, 16 Aug 2015 11:23:44 +0200 Subject: clocksource: atmel-st: get and use slow clock The current slow clock rate is hardcoded. Properly get the slow clock and use its rate. Signed-off-by: Alexandre Belloni Acked-by: Daniel Lezcano diff --git a/drivers/clocksource/timer-atmel-st.c b/drivers/clocksource/timer-atmel-st.c index 41b7b6d..29d21d6 100644 --- a/drivers/clocksource/timer-atmel-st.c +++ b/drivers/clocksource/timer-atmel-st.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include #include @@ -33,9 +34,7 @@ static unsigned long last_crtr; static u32 irqmask; static struct clock_event_device clkevt; static struct regmap *regmap_st; - -#define AT91_SLOW_CLOCK 32768 -#define RM9200_TIMER_LATCH ((AT91_SLOW_CLOCK + HZ/2) / HZ) +static int timer_latch; /* * The ST_CRTR is updated asynchronously to the master clock ... but @@ -82,8 +81,8 @@ static irqreturn_t at91rm9200_timer_interrupt(int irq, void *dev_id) if (sr & AT91_ST_PITS) { u32 crtr = read_CRTR(); - while (((crtr - last_crtr) & AT91_ST_CRTV) >= RM9200_TIMER_LATCH) { - last_crtr += RM9200_TIMER_LATCH; + while (((crtr - last_crtr) & AT91_ST_CRTV) >= timer_latch) { + last_crtr += timer_latch; clkevt.event_handler(&clkevt); } return IRQ_HANDLED; @@ -144,7 +143,7 @@ static int clkevt32k_set_periodic(struct clock_event_device *dev) /* PIT for periodic irqs; fixed rate of 1/HZ */ irqmask = AT91_ST_PITS; - regmap_write(regmap_st, AT91_ST_PIMR, RM9200_TIMER_LATCH); + regmap_write(regmap_st, AT91_ST_PIMR, timer_latch); regmap_write(regmap_st, AT91_ST_IER, irqmask); return 0; } @@ -197,7 +196,8 @@ static struct clock_event_device clkevt = { */ static void __init atmel_st_timer_init(struct device_node *node) { - unsigned int val; + struct clk *sclk; + unsigned int sclk_rate, val; int irq, ret; regmap_st = syscon_node_to_regmap(node); @@ -221,6 +221,19 @@ static void __init atmel_st_timer_init(struct device_node *node) if (ret) panic(pr_fmt("Unable to setup IRQ\n")); + sclk = of_clk_get(node, 0); + if (IS_ERR(sclk)) + panic(pr_fmt("Unable to get slow clock\n")); + + clk_prepare_enable(sclk); + if (ret) + panic(pr_fmt("Could not enable slow clock\n")); + + sclk_rate = clk_get_rate(sclk); + if (!sclk_rate) + panic(pr_fmt("Invalid slow clock rate\n")); + timer_latch = (sclk_rate + HZ / 2) / HZ; + /* The 32KiHz "Slow Clock" (tick every 30517.58 nanoseconds) is used * directly for the clocksource and all clockevents, after adjusting * its prescaler from the 1 Hz default. @@ -229,11 +242,11 @@ static void __init atmel_st_timer_init(struct device_node *node) /* Setup timer clockevent, with minimum of two ticks (important!!) */ clkevt.cpumask = cpumask_of(0); - clockevents_config_and_register(&clkevt, AT91_SLOW_CLOCK, + clockevents_config_and_register(&clkevt, sclk_rate, 2, AT91_ST_ALMV); /* register clocksource */ - clocksource_register_hz(&clk32k, AT91_SLOW_CLOCK); + clocksource_register_hz(&clk32k, sclk_rate); } CLOCKSOURCE_OF_DECLARE(atmel_st_timer, "atmel,at91rm9200-st", atmel_st_timer_init); -- cgit v0.10.2 From eed9fb9df47898ea62d71be7dcc3b36d95819a7c Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Sun, 16 Aug 2015 11:23:45 +0200 Subject: clocksource: tcb_clksrc: fix setup_clkevents error path t2_clk is already disabled before request_irq(), it must not be disabled again. Signed-off-by: Boris Brezillon Signed-off-by: Alexandre Belloni Acked-by: Daniel Lezcano diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c index d28d2fe..f8d11fc 100644 --- a/drivers/clocksource/tcb_clksrc.c +++ b/drivers/clocksource/tcb_clksrc.c @@ -208,7 +208,7 @@ 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_disable_unprepare(t2_clk); + clk_unprepare(t2_clk); return ret; } -- cgit v0.10.2 From 7d8d05d11473a169ab4d53bc7fc23d1fe3f1959f Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Sun, 16 Aug 2015 11:23:46 +0200 Subject: 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 Signed-off-by: Alexandre Belloni Acked-by: Greg Kroah-Hartman Acked-by: Daniel Lezcano Acked-by: Thierry Reding diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c index f8d11fc..6ee9140 100644 --- a/drivers/clocksource/tcb_clksrc.c +++ b/drivers/clocksource/tcb_clksrc.c @@ -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; } diff --git a/drivers/misc/atmel_tclib.c b/drivers/misc/atmel_tclib.c index 0ca05c3..ac24a4b 100644 --- a/drivers/misc/atmel_tclib.c +++ b/drivers/misc/atmel_tclib.c @@ -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)) 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 @@ 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; diff --git a/include/linux/atmel_tc.h b/include/linux/atmel_tc.h index b87c1c7..468fdfa 100644 --- a/include/linux/atmel_tc.h +++ b/include/linux/atmel_tc.h @@ -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; }; -- cgit v0.10.2