diff options
Diffstat (limited to 'arch/arm/mach-s3c2440/fiq_c_isr.c')
| -rw-r--r-- | arch/arm/mach-s3c2440/fiq_c_isr.c | 56 |
1 files changed, 47 insertions, 9 deletions
diff --git a/arch/arm/mach-s3c2440/fiq_c_isr.c b/arch/arm/mach-s3c2440/fiq_c_isr.c index 12f45276b03..a71a234d86c 100644 --- a/arch/arm/mach-s3c2440/fiq_c_isr.c +++ b/arch/arm/mach-s3c2440/fiq_c_isr.c @@ -18,6 +18,9 @@ #include <asm/plat-s3c24xx/cpu.h> #include <asm/plat-s3c24xx/irq.h> +#include <asm/arch/pwm.h> +#include <asm/plat-s3c/regs-timer.h> + /* * Major Caveats for using FIQ * --------------------------- @@ -66,6 +69,10 @@ static u8 u8aFiqStack[4096]; u32 _fiq_ack_mask; /* used by isr exit define */ unsigned long _fiq_count_fiqs; /* used by isr exit define */ static int _fiq_irq; /* private ; irq index we were started with, or 0 */ +struct s3c2410_pwm pwm_timer_fiq; +int _fiq_timer_index; +u16 _fiq_timer_divisor; + /* this function must live in the monolithic kernel somewhere! A module is * NOT good enough! @@ -110,23 +117,45 @@ static struct attribute_group s3c2440_fiq_attr_group = { * you still need to clear the source interrupt in S3C2410_INTMSK to get * anything good happening */ -static void fiq_init_irq_source(int irq_index_fiq) +static int fiq_init_irq_source(int irq_index_fiq) { + int rc = 0; + if (!irq_index_fiq) /* no interrupt */ - return; + goto bail; - printk(KERN_INFO"Enabling FIQ using int idx %d\n", - irq_index_fiq - S3C2410_CPUIRQ_OFFSET); local_fiq_disable(); _fiq_irq = irq_index_fiq; _fiq_ack_mask = 1 << (irq_index_fiq - S3C2410_CPUIRQ_OFFSET); + timer_index = (irq_index_fiq - IRQ_TIMER0); + + /* set up the timer to operate as a pwm device */ + + rc = s3c2410_pwm_init(&pwm_timer_fiq); + if (rc) + goto bail; + + pwm_timer_fiq.timerid = PWM0 + timer_index; + pwm_timer_fiq.prescaler = (6 - 1) / 2; + pwm_timer_fiq.divider = S3C2410_TCFG1_MUX3_DIV2; + /* default rate == ~32us */ + pwm_timer_fiq.counter = pwm_timer_fiq.comparer = + timer_divisor = 64; + + rc = s3c2410_pwm_enable(&pwm_timer_fiq); + if (rc) + goto bail; + + s3c2410_pwm_start(&pwm_timer_fiq); /* let our selected interrupt be a magic FIQ interrupt */ __raw_writel(_fiq_ack_mask, S3C2410_INTMOD); /* it's ready to go as soon as we unmask the source in S3C2410_INTMSK */ local_fiq_enable(); +bail: + return rc; } @@ -139,15 +168,13 @@ static void fiq_disable_irq_source(void) _fiq_irq = 0; /* no active source interrupt now either */ } -/* this starts FIQ timer events... they continue until the FIQ ISR sees that - * its work is done and it turns off the timer. After setting up the fiq_ipc - * struct with new work, you call this to start FIQ timer actions up again. - * Only the FIQ ISR decides when it is done and controls turning off the - * timer events. +/* + * fiq_kick() forces a FIQ event to happen shortly after leaving the routine */ void fiq_kick(void) { unsigned long flags; + u32 tcon; /* we have to take care about FIQ because this modification is * non-atomic, FIQ could come in after the read and before the @@ -156,15 +183,24 @@ void fiq_kick(void) */ local_save_flags(flags); local_fiq_disable(); + /* allow FIQs to resume */ __raw_writel(__raw_readl(S3C2410_INTMSK) & ~(1 << (_fiq_irq - S3C2410_CPUIRQ_OFFSET)), S3C2410_INTMSK); + tcon = __raw_readl(S3C2410_TCON) & ~S3C2410_TCON_T3START; + /* fake the timer to a count of 1 */ + __raw_writel(1, S3C2410_TCNTB(timer_index)); + __raw_writel(tcon | S3C2410_TCON_T3MANUALUPD, S3C2410_TCON); + __raw_writel(tcon | S3C2410_TCON_T3MANUALUPD | S3C2410_TCON_T3START, + S3C2410_TCON); + __raw_writel(tcon | S3C2410_TCON_T3START, S3C2410_TCON); local_irq_restore(flags); } EXPORT_SYMBOL_GPL(fiq_kick); + static int __init sc32440_fiq_probe(struct platform_device *pdev) { struct resource *r = platform_get_resource(pdev, IORESOURCE_IRQ, 0); @@ -172,6 +208,8 @@ static int __init sc32440_fiq_probe(struct platform_device *pdev) if (!r) return -EIO; /* configure for the interrupt we are meant to use */ + printk(KERN_INFO"Enabling FIQ using irq %d\n", r->start); + fiq_init_irq_source(r->start); return sysfs_create_group(&pdev->dev.kobj, &s3c2440_fiq_attr_group); |