From: Tao Ren taoren@fb.com
[ Upstream commit 86fe57fc47b17b3528fa5497fc57e158d846c4ea ]
TIMER_INTR_MASK register (Base Address of Timer + 0x38) is not designed for masking interrupts on ast2500 chips, and it's not even listed in ast2400 datasheet, so it's not safe to access TIMER_INTR_MASK on aspeed chips.
Similarly, TIMER_INTR_STATE register (Base Address of Timer + 0x34) is not interrupt status register on ast2400 and ast2500 chips. Although there is no side effect to reset the register in fttmr010_common_init(), it's just misleading to do so.
Besides, "count_down" is renamed to "is_aspeed" in "fttmr010" structure, and more comments are added so the code is more readble.
Signed-off-by: Tao Ren taoren@fb.com Reviewed-by: Linus Walleij linus.walleij@linaro.org Signed-off-by: Daniel Lezcano daniel.lezcano@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/clocksource/timer-fttmr010.c | 73 ++++++++++++++++------------ 1 file changed, 42 insertions(+), 31 deletions(-)
diff --git a/drivers/clocksource/timer-fttmr010.c b/drivers/clocksource/timer-fttmr010.c index cf93f6419b514..fadff7915dd9c 100644 --- a/drivers/clocksource/timer-fttmr010.c +++ b/drivers/clocksource/timer-fttmr010.c @@ -21,7 +21,7 @@ #include <linux/delay.h>
/* - * Register definitions for the timers + * Register definitions common for all the timer variants. */ #define TIMER1_COUNT (0x00) #define TIMER1_LOAD (0x04) @@ -36,9 +36,10 @@ #define TIMER3_MATCH1 (0x28) #define TIMER3_MATCH2 (0x2c) #define TIMER_CR (0x30) -#define TIMER_INTR_STATE (0x34) -#define TIMER_INTR_MASK (0x38)
+/* + * Control register (TMC30) bit fields for fttmr010/gemini/moxart timers. + */ #define TIMER_1_CR_ENABLE BIT(0) #define TIMER_1_CR_CLOCK BIT(1) #define TIMER_1_CR_INT BIT(2) @@ -53,8 +54,9 @@ #define TIMER_3_CR_UPDOWN BIT(11)
/* - * The Aspeed AST2400 moves bits around in the control register - * and lacks bits for setting the timer to count upwards. + * Control register (TMC30) bit fields for aspeed ast2400/ast2500 timers. + * The aspeed timers move bits around in the control register and lacks + * bits for setting the timer to count upwards. */ #define TIMER_1_CR_ASPEED_ENABLE BIT(0) #define TIMER_1_CR_ASPEED_CLOCK BIT(1) @@ -66,6 +68,18 @@ #define TIMER_3_CR_ASPEED_CLOCK BIT(9) #define TIMER_3_CR_ASPEED_INT BIT(10)
+/* + * Interrupt status/mask register definitions for fttmr010/gemini/moxart + * timers. + * The registers don't exist and they are not needed on aspeed timers + * because: + * - aspeed timer overflow interrupt is controlled by bits in Control + * Register (TMC30). + * - aspeed timers always generate interrupt when either one of the + * Match registers equals to Status register. + */ +#define TIMER_INTR_STATE (0x34) +#define TIMER_INTR_MASK (0x38) #define TIMER_1_INT_MATCH1 BIT(0) #define TIMER_1_INT_MATCH2 BIT(1) #define TIMER_1_INT_OVERFLOW BIT(2) @@ -80,7 +94,7 @@ struct fttmr010 { void __iomem *base; unsigned int tick_rate; - bool count_down; + bool is_aspeed; u32 t1_enable_val; struct clock_event_device clkevt; #ifdef CONFIG_ARM @@ -130,7 +144,7 @@ static int fttmr010_timer_set_next_event(unsigned long cycles, cr &= ~fttmr010->t1_enable_val; writel(cr, fttmr010->base + TIMER_CR);
- if (fttmr010->count_down) { + if (fttmr010->is_aspeed) { /* * ASPEED Timer Controller will load TIMER1_LOAD register * into TIMER1_COUNT register when the timer is re-enabled. @@ -175,16 +189,17 @@ static int fttmr010_timer_set_oneshot(struct clock_event_device *evt)
/* Setup counter start from 0 or ~0 */ writel(0, fttmr010->base + TIMER1_COUNT); - if (fttmr010->count_down) + if (fttmr010->is_aspeed) { writel(~0, fttmr010->base + TIMER1_LOAD); - else + } else { writel(0, fttmr010->base + TIMER1_LOAD);
- /* Enable interrupt */ - cr = readl(fttmr010->base + TIMER_INTR_MASK); - cr &= ~(TIMER_1_INT_OVERFLOW | TIMER_1_INT_MATCH2); - cr |= TIMER_1_INT_MATCH1; - writel(cr, fttmr010->base + TIMER_INTR_MASK); + /* Enable interrupt */ + cr = readl(fttmr010->base + TIMER_INTR_MASK); + cr &= ~(TIMER_1_INT_OVERFLOW | TIMER_1_INT_MATCH2); + cr |= TIMER_1_INT_MATCH1; + writel(cr, fttmr010->base + TIMER_INTR_MASK); + }
return 0; } @@ -201,9 +216,8 @@ static int fttmr010_timer_set_periodic(struct clock_event_device *evt) writel(cr, fttmr010->base + TIMER_CR);
/* Setup timer to fire at 1/HZ intervals. */ - if (fttmr010->count_down) { + if (fttmr010->is_aspeed) { writel(period, fttmr010->base + TIMER1_LOAD); - writel(0, fttmr010->base + TIMER1_MATCH1); } else { cr = 0xffffffff - (period - 1); writel(cr, fttmr010->base + TIMER1_COUNT); @@ -281,23 +295,21 @@ static int __init fttmr010_common_init(struct device_node *np, bool is_aspeed) }
/* - * The Aspeed AST2400 moves bits around in the control register, - * otherwise it works the same. + * The Aspeed timers move bits around in the control register. */ if (is_aspeed) { fttmr010->t1_enable_val = TIMER_1_CR_ASPEED_ENABLE | TIMER_1_CR_ASPEED_INT; - /* Downward not available */ - fttmr010->count_down = true; + fttmr010->is_aspeed = true; } else { fttmr010->t1_enable_val = TIMER_1_CR_ENABLE | TIMER_1_CR_INT; - }
- /* - * Reset the interrupt mask and status - */ - writel(TIMER_INT_ALL_MASK, fttmr010->base + TIMER_INTR_MASK); - writel(0, fttmr010->base + TIMER_INTR_STATE); + /* + * Reset the interrupt mask and status + */ + writel(TIMER_INT_ALL_MASK, fttmr010->base + TIMER_INTR_MASK); + writel(0, fttmr010->base + TIMER_INTR_STATE); + }
/* * Enable timer 1 count up, timer 2 count up, except on Aspeed, @@ -306,9 +318,8 @@ static int __init fttmr010_common_init(struct device_node *np, bool is_aspeed) if (is_aspeed) val = TIMER_2_CR_ASPEED_ENABLE; else { - val = TIMER_2_CR_ENABLE; - if (!fttmr010->count_down) - val |= TIMER_1_CR_UPDOWN | TIMER_2_CR_UPDOWN; + val = TIMER_2_CR_ENABLE | TIMER_1_CR_UPDOWN | + TIMER_2_CR_UPDOWN; } writel(val, fttmr010->base + TIMER_CR);
@@ -321,7 +332,7 @@ static int __init fttmr010_common_init(struct device_node *np, bool is_aspeed) writel(0, fttmr010->base + TIMER2_MATCH1); writel(0, fttmr010->base + TIMER2_MATCH2);
- if (fttmr010->count_down) { + if (fttmr010->is_aspeed) { writel(~0, fttmr010->base + TIMER2_LOAD); clocksource_mmio_init(fttmr010->base + TIMER2_COUNT, "FTTMR010-TIMER2", @@ -371,7 +382,7 @@ static int __init fttmr010_common_init(struct device_node *np, bool is_aspeed)
#ifdef CONFIG_ARM /* Also use this timer for delays */ - if (fttmr010->count_down) + if (fttmr010->is_aspeed) fttmr010->delay_timer.read_current_timer = fttmr010_read_current_timer_down; else