diff options
Diffstat (limited to 'arch/arm/mach-s3c2442/gta02-fiq.c')
| -rw-r--r-- | arch/arm/mach-s3c2442/gta02-fiq.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c2442/gta02-fiq.c b/arch/arm/mach-s3c2442/gta02-fiq.c new file mode 100644 index 00000000000..600eb64cf9f --- /dev/null +++ b/arch/arm/mach-s3c2442/gta02-fiq.c @@ -0,0 +1,144 @@ +#include <linux/kernel.h> + +#include <asm/fiq.h> +#include <plat/pwm.h> +#include <mach/regs-irq.h> +#include <mach/irqs.h> +#include <linux/io.h> +#include <linux/hdq.h> + +/* ------------------------------------------------------------------------------- + * GTA02 FIQ related + * + * Calls into vibrator and hdq and based on the return values + * determines if we the FIQ source be kept alive + */ + +#define DIVISOR_FROM_US(x) ((x) << 3) + +#ifdef CONFIG_HDQ_GPIO_BITBANG +#define FIQ_DIVISOR_HDQ DIVISOR_FROM_US(HDQ_SAMPLE_PERIOD_US) +extern int hdq_fiq_handler(void); +#endif + +#ifdef CONFIG_LEDS_GTA02_VIBRATOR +#define FIQ_DIVISOR_VIBRATOR DIVISOR_FROM_US(100) +extern int gta02_vibrator_fiq_handler(void); +#endif + +/* Global data related to our fiq source */ +static uint32_t gta02_fiq_ack_mask; +static struct s3c2410_pwm gta02_fiq_pwm_timer; +static uint16_t gta02_fiq_timer_index; +static int gta02_fiq_irq; + +void gta02_fiq_handler(void) +{ + uint16_t divisor = 0xffff; + + /* disable further timer interrupts if nobody has any work + * or adjust rate according to who still has work + * + * CAUTION: it means forground code must disable FIQ around + * its own non-atomic S3C2410_INTMSK changes... not common + * thankfully and taken care of by the fiq-basis patch + */ + +#ifdef CONFIG_HDQ_GPIO_BITBANG + if (hdq_fiq_handler()) + divisor = FIQ_DIVISOR_HDQ; +#endif + +#ifdef CONFIG_LEDS_GTA02_VIBRATOR + if (gta02_vibrator_fiq_handler()) + divisor = FIQ_DIVISOR_VIBRATOR; +#endif + + if (divisor == 0xffff) /* mask the fiq irq source */ + __raw_writel(__raw_readl(S3C2410_INTMSK) | gta02_fiq_ack_mask, + S3C2410_INTMSK); + else /* still working, maybe at a different rate */ + __raw_writel(divisor, S3C2410_TCNTB(gta02_fiq_timer_index)); + + __raw_writel(gta02_fiq_ack_mask, S3C2410_SRCPND); +} + +void gta02_fiq_kick(void) +{ + unsigned long flags; + uint32_t tcon; + + /* we have to take care about FIQ because this modification is + * non-atomic, FIQ could come in after the read and before the + * writeback and its changes to the register would be lost + * (platform INTMSK mod code is taken care of already) + */ + local_save_flags(flags); + local_fiq_disable(); + /* allow FIQs to resume */ + __raw_writel(__raw_readl(S3C2410_INTMSK) & + ~(1 << (gta02_fiq_irq - S3C2410_CPUIRQ_OFFSET)), + S3C2410_INTMSK); + tcon = __raw_readl(S3C2410_TCON) & ~S3C2410_TCON_T2START; + /* fake the timer to a count of 1 */ + __raw_writel(1, S3C2410_TCNTB(gta02_fiq_timer_index)); + __raw_writel(tcon | S3C2410_TCON_T2MANUALUPD, S3C2410_TCON); + __raw_writel(tcon | S3C2410_TCON_T2MANUALUPD | S3C2410_TCON_T2START, + S3C2410_TCON); + __raw_writel(tcon | S3C2410_TCON_T2START, S3C2410_TCON); + local_irq_restore(flags); +} + +int gta02_fiq_enable(void) +{ + int irq_index_fiq = IRQ_TIMER2; + int rc = 0; + + local_fiq_disable(); + + gta02_fiq_irq = irq_index_fiq; + gta02_fiq_ack_mask = 1 << (irq_index_fiq - S3C2410_CPUIRQ_OFFSET); + gta02_fiq_timer_index = (irq_index_fiq - IRQ_TIMER0); + + /* set up the timer to operate as a pwm device */ + + rc = s3c2410_pwm_init(>a02_fiq_pwm_timer); + if (rc) + goto bail; + + gta02_fiq_pwm_timer.timerid = PWM0 + gta02_fiq_timer_index; + gta02_fiq_pwm_timer.prescaler = (6 - 1) / 2; + gta02_fiq_pwm_timer.divider = S3C2410_TCFG1_MUX3_DIV2; + /* default rate == ~32us */ + gta02_fiq_pwm_timer.counter = gta02_fiq_pwm_timer.comparer = 3000; + + rc = s3c2410_pwm_enable(>a02_fiq_pwm_timer); + if (rc) + goto bail; + + s3c2410_pwm_start(>a02_fiq_pwm_timer); + + /* let our selected interrupt be a magic FIQ interrupt */ + __raw_writel(gta02_fiq_ack_mask, S3C2410_INTMOD); + + /* it's ready to go as soon as we unmask the source in S3C2410_INTMSK */ + local_fiq_enable(); + + set_fiq_c_handler(gta02_fiq_handler); + + return 0; + +bail: + printk(KERN_ERR "Could not initialize FIQ for GTA02: %d\n", rc); + + return rc; +} + +void gta02_fiq_disable(void) +{ + __raw_writel(0, S3C2410_INTMOD); + local_fiq_disable(); + gta02_fiq_irq = 0; /* no active source interrupt now either */ + +} +/* -------------------- /GTA02 FIQ Handler ------------------------------------- */ |