diff options
author | Josh Cartwright <josh.cartwright@ni.com> | 2012-10-31 19:56:14 (GMT) |
---|---|---|
committer | Michal Simek <michal.simek@xilinx.com> | 2012-11-14 15:10:42 (GMT) |
commit | 91dc985c5e51af7036c1ccf9cea1b05662c96791 (patch) | |
tree | dd34ce5f4a2946cacf11bfceecce653792158d31 /arch/arm/mach-zynq | |
parent | 0f586fbf6f6a9119392a5cb0f193ac11c753b09e (diff) | |
download | linux-91dc985c5e51af7036c1ccf9cea1b05662c96791.tar.xz |
ARM: zynq: add clk binding support to the ttc
Add support for retrieving TTC configuration from device tree. This
includes the ability to pull information about the driving clocks from
the of_clk bindings.
Signed-off-by: Josh Cartwright <josh.cartwright@ni.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Diffstat (limited to 'arch/arm/mach-zynq')
-rw-r--r-- | arch/arm/mach-zynq/timer.c | 287 |
1 files changed, 165 insertions, 122 deletions
diff --git a/arch/arm/mach-zynq/timer.c b/arch/arm/mach-zynq/timer.c index c93cbe5..9662306 100644 --- a/arch/arm/mach-zynq/timer.c +++ b/arch/arm/mach-zynq/timer.c @@ -23,31 +23,15 @@ #include <linux/clocksource.h> #include <linux/clockchips.h> #include <linux/io.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/slab.h> +#include <linux/clk-provider.h> #include <mach/zynq_soc.h> #include "common.h" -#define IRQ_TIMERCOUNTER0 42 - -/* - * This driver configures the 2 16-bit count-up timers as follows: - * - * T1: Timer 1, clocksource for generic timekeeping - * T2: Timer 2, clockevent source for hrtimers - * T3: Timer 3, <unused> - * - * The input frequency to the timer module for emulation is 2.5MHz which is - * common to all the timer channels (T1, T2, and T3). With a pre-scaler of 32, - * the timers are clocked at 78.125KHz (12.8 us resolution). - * - * The input frequency to the timer module in silicon will be 200MHz. With the - * pre-scaler of 32, the timers are clocked at 6.25MHz (160ns resolution). - */ -#define XTTCPSS_CLOCKSOURCE 0 /* Timer 1 as a generic timekeeping */ -#define XTTCPSS_CLOCKEVENT 1 /* Timer 2 as a clock event */ - -#define XTTCPSS_TIMER_BASE TTC0_BASE -#define XTTCPCC_EVENT_TIMER_IRQ (IRQ_TIMERCOUNTER0 + 1) /* * Timer Register Offset Definitions of Timer 1, Increment base address by 4 * and use same offsets for Timer 2 @@ -64,9 +48,14 @@ #define XTTCPSS_CNT_CNTRL_DISABLE_MASK 0x1 -/* Setup the timers to use pre-scaling */ - -#define TIMER_RATE (PERIPHERAL_CLOCK_RATE / 32) +/* Setup the timers to use pre-scaling, using a fixed value for now that will + * work across most input frequency, but it may need to be more dynamic + */ +#define PRESCALE_EXPONENT 11 /* 2 ^ PRESCALE_EXPONENT = PRESCALE */ +#define PRESCALE 2048 /* The exponent must match this */ +#define CLK_CNTRL_PRESCALE ((PRESCALE_EXPONENT - 1) << 1) +#define CLK_CNTRL_PRESCALE_EN 1 +#define CNT_CNTRL_RESET (1<<4) /** * struct xttcpss_timer - This definition defines local timer structure @@ -74,11 +63,25 @@ * @base_addr: Base address of timer **/ struct xttcpss_timer { - void __iomem *base_addr; + void __iomem *base_addr; +}; + +struct xttcpss_timer_clocksource { + struct xttcpss_timer xttc; + struct clocksource cs; }; -static struct xttcpss_timer timers[2]; -static struct clock_event_device xttcpss_clockevent; +#define to_xttcpss_timer_clksrc(x) \ + container_of(x, struct xttcpss_timer_clocksource, cs) + +struct xttcpss_timer_clockevent { + struct xttcpss_timer xttc; + struct clock_event_device ce; + struct clk *clk; +}; + +#define to_xttcpss_timer_clkevent(x) \ + container_of(x, struct xttcpss_timer_clockevent, ce) /** * xttcpss_set_interval - Set the timer interval value @@ -100,7 +103,7 @@ static void xttcpss_set_interval(struct xttcpss_timer *timer, /* Reset the counter (0x10) so that it starts from 0, one-shot mode makes this needed for timing to be right. */ - ctrl_reg |= 0x10; + ctrl_reg |= CNT_CNTRL_RESET; ctrl_reg &= ~XTTCPSS_CNT_CNTRL_DISABLE_MASK; __raw_writel(ctrl_reg, timer->base_addr + XTTCPSS_CNT_CNTRL_OFFSET); } @@ -115,90 +118,31 @@ static void xttcpss_set_interval(struct xttcpss_timer *timer, **/ static irqreturn_t xttcpss_clock_event_interrupt(int irq, void *dev_id) { - struct clock_event_device *evt = &xttcpss_clockevent; - struct xttcpss_timer *timer = dev_id; + struct xttcpss_timer_clockevent *xttce = dev_id; + struct xttcpss_timer *timer = &xttce->xttc; /* Acknowledge the interrupt and call event handler */ __raw_writel(__raw_readl(timer->base_addr + XTTCPSS_ISR_OFFSET), timer->base_addr + XTTCPSS_ISR_OFFSET); - evt->event_handler(evt); + xttce->ce.event_handler(&xttce->ce); return IRQ_HANDLED; } -static struct irqaction event_timer_irq = { - .name = "xttcpss clockevent", - .flags = IRQF_DISABLED | IRQF_TIMER, - .handler = xttcpss_clock_event_interrupt, -}; - /** - * xttcpss_timer_hardware_init - Initialize the timer hardware - * - * Initialize the hardware to start the clock source, get the clock - * event timer ready to use, and hook up the interrupt. - **/ -static void __init xttcpss_timer_hardware_init(void) -{ - /* Setup the clock source counter to be an incrementing counter - * with no interrupt and it rolls over at 0xFFFF. Pre-scale - it by 32 also. Let it start running now. - */ - timers[XTTCPSS_CLOCKSOURCE].base_addr = XTTCPSS_TIMER_BASE; - - __raw_writel(0x0, timers[XTTCPSS_CLOCKSOURCE].base_addr + - XTTCPSS_IER_OFFSET); - __raw_writel(0x9, timers[XTTCPSS_CLOCKSOURCE].base_addr + - XTTCPSS_CLK_CNTRL_OFFSET); - __raw_writel(0x10, timers[XTTCPSS_CLOCKSOURCE].base_addr + - XTTCPSS_CNT_CNTRL_OFFSET); - - /* Setup the clock event timer to be an interval timer which - * is prescaled by 32 using the interval interrupt. Leave it - * disabled for now. - */ - - timers[XTTCPSS_CLOCKEVENT].base_addr = XTTCPSS_TIMER_BASE + 4; - - __raw_writel(0x23, timers[XTTCPSS_CLOCKEVENT].base_addr + - XTTCPSS_CNT_CNTRL_OFFSET); - __raw_writel(0x9, timers[XTTCPSS_CLOCKEVENT].base_addr + - XTTCPSS_CLK_CNTRL_OFFSET); - __raw_writel(0x1, timers[XTTCPSS_CLOCKEVENT].base_addr + - XTTCPSS_IER_OFFSET); - - /* Setup IRQ the clock event timer */ - event_timer_irq.dev_id = &timers[XTTCPSS_CLOCKEVENT]; - setup_irq(XTTCPCC_EVENT_TIMER_IRQ, &event_timer_irq); -} - -/** - * __raw_readl_cycles - Reads the timer counter register + * __xttc_clocksource_read - Reads the timer counter register * * returns: Current timer counter register value **/ -static cycle_t __raw_readl_cycles(struct clocksource *cs) +static cycle_t __xttc_clocksource_read(struct clocksource *cs) { - struct xttcpss_timer *timer = &timers[XTTCPSS_CLOCKSOURCE]; + struct xttcpss_timer *timer = &to_xttcpss_timer_clksrc(cs)->xttc; return (cycle_t)__raw_readl(timer->base_addr + XTTCPSS_COUNT_VAL_OFFSET); } - -/* - * Instantiate and initialize the clock source structure - */ -static struct clocksource clocksource_xttcpss = { - .name = "xttcpss_timer1", - .rating = 200, /* Reasonable clock source */ - .read = __raw_readl_cycles, - .mask = CLOCKSOURCE_MASK(16), - .flags = CLOCK_SOURCE_IS_CONTINUOUS, -}; - - /** * xttcpss_set_next_event - Sets the time interval for next event * @@ -210,7 +154,8 @@ static struct clocksource clocksource_xttcpss = { static int xttcpss_set_next_event(unsigned long cycles, struct clock_event_device *evt) { - struct xttcpss_timer *timer = &timers[XTTCPSS_CLOCKEVENT]; + struct xttcpss_timer_clockevent *xttce = to_xttcpss_timer_clkevent(evt); + struct xttcpss_timer *timer = &xttce->xttc; xttcpss_set_interval(timer, cycles); return 0; @@ -225,12 +170,15 @@ static int xttcpss_set_next_event(unsigned long cycles, static void xttcpss_set_mode(enum clock_event_mode mode, struct clock_event_device *evt) { - struct xttcpss_timer *timer = &timers[XTTCPSS_CLOCKEVENT]; + struct xttcpss_timer_clockevent *xttce = to_xttcpss_timer_clkevent(evt); + struct xttcpss_timer *timer = &xttce->xttc; u32 ctrl_reg; switch (mode) { case CLOCK_EVT_MODE_PERIODIC: - xttcpss_set_interval(timer, TIMER_RATE / HZ); + xttcpss_set_interval(timer, + DIV_ROUND_CLOSEST(clk_get_rate(xttce->clk), + PRESCALE * HZ)); break; case CLOCK_EVT_MODE_ONESHOT: case CLOCK_EVT_MODE_UNUSED: @@ -251,15 +199,106 @@ static void xttcpss_set_mode(enum clock_event_mode mode, } } -/* - * Instantiate and initialize the clock event structure - */ -static struct clock_event_device xttcpss_clockevent = { - .name = "xttcpss_timer2", - .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, - .set_next_event = xttcpss_set_next_event, - .set_mode = xttcpss_set_mode, - .rating = 200, +static void __init zynq_ttc_setup_clocksource(struct device_node *np, + void __iomem *base) +{ + struct xttcpss_timer_clocksource *ttccs; + struct clk *clk; + int err; + u32 reg; + + ttccs = kzalloc(sizeof(*ttccs), GFP_KERNEL); + if (WARN_ON(!ttccs)) + return; + + err = of_property_read_u32(np, "reg", ®); + if (WARN_ON(err)) + return; + + clk = of_clk_get_by_name(np, "cpu_1x"); + if (WARN_ON(IS_ERR(clk))) + return; + + err = clk_prepare_enable(clk); + if (WARN_ON(err)) + return; + + ttccs->xttc.base_addr = base + reg * 4; + + ttccs->cs.name = np->name; + ttccs->cs.rating = 200; + ttccs->cs.read = __xttc_clocksource_read; + ttccs->cs.mask = CLOCKSOURCE_MASK(16); + ttccs->cs.flags = CLOCK_SOURCE_IS_CONTINUOUS; + + __raw_writel(0x0, ttccs->xttc.base_addr + XTTCPSS_IER_OFFSET); + __raw_writel(CLK_CNTRL_PRESCALE | CLK_CNTRL_PRESCALE_EN, + ttccs->xttc.base_addr + XTTCPSS_CLK_CNTRL_OFFSET); + __raw_writel(CNT_CNTRL_RESET, + ttccs->xttc.base_addr + XTTCPSS_CNT_CNTRL_OFFSET); + + err = clocksource_register_hz(&ttccs->cs, clk_get_rate(clk) / PRESCALE); + if (WARN_ON(err)) + return; +} + +static void __init zynq_ttc_setup_clockevent(struct device_node *np, + void __iomem *base) +{ + struct xttcpss_timer_clockevent *ttcce; + int err, irq; + u32 reg; + + ttcce = kzalloc(sizeof(*ttcce), GFP_KERNEL); + if (WARN_ON(!ttcce)) + return; + + err = of_property_read_u32(np, "reg", ®); + if (WARN_ON(err)) + return; + + ttcce->xttc.base_addr = base + reg * 4; + + ttcce->clk = of_clk_get_by_name(np, "cpu_1x"); + if (WARN_ON(IS_ERR(ttcce->clk))) + return; + + err = clk_prepare_enable(ttcce->clk); + if (WARN_ON(err)) + return; + + irq = irq_of_parse_and_map(np, 0); + if (WARN_ON(!irq)) + return; + + ttcce->ce.name = np->name; + ttcce->ce.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT; + ttcce->ce.set_next_event = xttcpss_set_next_event; + ttcce->ce.set_mode = xttcpss_set_mode; + ttcce->ce.rating = 200; + ttcce->ce.irq = irq; + + __raw_writel(0x23, ttcce->xttc.base_addr + XTTCPSS_CNT_CNTRL_OFFSET); + __raw_writel(CLK_CNTRL_PRESCALE | CLK_CNTRL_PRESCALE_EN, + ttcce->xttc.base_addr + XTTCPSS_CLK_CNTRL_OFFSET); + __raw_writel(0x1, ttcce->xttc.base_addr + XTTCPSS_IER_OFFSET); + + err = request_irq(irq, xttcpss_clock_event_interrupt, IRQF_TIMER, + np->name, ttcce); + if (WARN_ON(err)) + return; + + clockevents_config_and_register(&ttcce->ce, + clk_get_rate(ttcce->clk) / PRESCALE, + 1, 0xfffe); +} + +static const __initconst struct of_device_id zynq_ttc_match[] = { + { .compatible = "xlnx,ttc-counter-clocksource", + .data = zynq_ttc_setup_clocksource, }, + { .compatible = "xlnx,ttc-counter-clockevent", + .data = zynq_ttc_setup_clockevent, }, + {} }; /** @@ -270,21 +309,25 @@ static struct clock_event_device xttcpss_clockevent = { **/ void __init xttcpss_timer_init(void) { - xttcpss_timer_hardware_init(); - clocksource_register_hz(&clocksource_xttcpss, TIMER_RATE); - - /* Calculate the parameters to allow the clockevent to operate using - integer math - */ - clockevents_calc_mult_shift(&xttcpss_clockevent, TIMER_RATE, 4); - - xttcpss_clockevent.max_delta_ns = - clockevent_delta2ns(0xfffe, &xttcpss_clockevent); - xttcpss_clockevent.min_delta_ns = - clockevent_delta2ns(1, &xttcpss_clockevent); - - /* Indicate that clock event is on 1st CPU as SMP boot needs it */ - - xttcpss_clockevent.cpumask = cpumask_of(0); - clockevents_register_device(&xttcpss_clockevent); + struct device_node *np; + + for_each_compatible_node(np, NULL, "xlnx,ttc") { + struct device_node *np_chld; + void __iomem *base; + + base = of_iomap(np, 0); + if (WARN_ON(!base)) + return; + + for_each_available_child_of_node(np, np_chld) { + int (*cb)(struct device_node *np, void __iomem *base); + const struct of_device_id *match; + + match = of_match_node(zynq_ttc_match, np_chld); + if (match) { + cb = match->data; + cb(np_chld, base); + } + } + } } |