diff options
Diffstat (limited to 'arch/arm/mach-s3c2440/gta02-fiq.c')
-rw-r--r-- | arch/arm/mach-s3c2440/gta02-fiq.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c2440/gta02-fiq.c b/arch/arm/mach-s3c2440/gta02-fiq.c new file mode 100644 index 00000000000..d91c52341d5 --- /dev/null +++ b/arch/arm/mach-s3c2440/gta02-fiq.c @@ -0,0 +1,135 @@ +#include <linux/kernel.h> + +#include <asm/fiq.h> +#include <mach/regs-irq.h> +#include <plat/regs-timer.h> +#include <mach/irqs.h> +#include <linux/io.h> +#include <linux/pwm.h> +#include <linux/err.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 + +/* Global data related to our fiq source */ +static uint32_t gta02_fiq_ack_mask; +static const int gta02_gta02_fiq_timer_id = 2; + +struct pwm_device* gta02_fiq_timer; + +void gta02_fiq_handler(void) +{ + unsigned long intmask; + int keep_running = 0; + /* 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 + keep_running = hdq_fiq_handler(); +#endif + if (!keep_running) { + /* Disable irq */ + intmask = __raw_readl(S3C2410_INTMSK); + intmask |= (gta02_fiq_ack_mask); + __raw_writel(intmask, S3C2410_INTMSK); + } + + __raw_writel(gta02_fiq_ack_mask, S3C2410_SRCPND); +} + +void gta02_fiq_kick(void) +{ + unsigned long flags; + unsigned long intmask; + /* 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 */ + intmask = __raw_readl(S3C2410_INTMSK); + intmask &= ~(gta02_fiq_ack_mask); + __raw_writel(intmask, S3C2410_INTMSK); + + local_irq_restore(flags); + +} + +int gta02_fiq_enable(void) +{ + int ret = 0; + + local_fiq_disable(); + + gta02_fiq_timer = pwm_request(gta02_gta02_fiq_timer_id, "fiq timer"); + + if (IS_ERR(gta02_fiq_timer)) { + ret = PTR_ERR(gta02_fiq_timer); + printk("GTA02 FIQ: Could not request fiq timer: %d\n", ret); + return ret; + } + + gta02_fiq_ack_mask = 1 << (IRQ_TIMER0 + gta02_gta02_fiq_timer_id + - S3C2410_CPUIRQ_OFFSET); + + + ret = pwm_config(gta02_fiq_timer, HDQ_SAMPLE_PERIOD_US * 1000, + HDQ_SAMPLE_PERIOD_US * 1000); + if (ret) { + printk("GTA02 FIQ: Could not configure fiq timer: %d\n", ret); + goto err; + } + + set_fiq_c_handler(gta02_fiq_handler); + + __raw_writel(gta02_fiq_ack_mask, S3C2410_INTMOD); + + pwm_enable(gta02_fiq_timer); + + local_fiq_enable(); + + return 0; + +err: + pwm_free(gta02_fiq_timer); + + return ret; +} + +void gta02_fiq_disable(void) +{ + local_fiq_disable(); + + if (!gta02_fiq_timer) + return; + + __raw_writel(0, S3C2410_INTMOD); + set_fiq_c_handler(NULL); + + pwm_disable(gta02_fiq_timer); + + pwm_free(gta02_fiq_timer); + + gta02_fiq_timer = NULL; +} +/* -------------------- /GTA02 FIQ Handler ------------------------------------- */ |