Commit 91dc985c authored by Josh Cartwright's avatar Josh Cartwright Committed by Michal Simek

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: default avatarJosh Cartwright <josh.cartwright@ni.com>
Acked-by: default avatarMichal Simek <michal.simek@xilinx.com>
parent 0f586fbf
......@@ -109,5 +109,58 @@ cpu_clk: cpu_clk {
};
};
};
ttc0: ttc0@f8001000 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "xlnx,ttc";
reg = <0xF8001000 0x1000>;
clocks = <&cpu_clk 3>;
clock-names = "cpu_1x";
clock-ranges;
ttc0_0: ttc0.0 {
status = "disabled";
reg = <0>;
interrupts = <0 10 4>;
};
ttc0_1: ttc0.1 {
status = "disabled";
reg = <1>;
interrupts = <0 11 4>;
};
ttc0_2: ttc0.2 {
status = "disabled";
reg = <2>;
interrupts = <0 12 4>;
};
};
ttc1: ttc1@f8002000 {
#interrupt-parent = <&intc>;
#address-cells = <1>;
#size-cells = <0>;
compatible = "xlnx,ttc";
reg = <0xF8002000 0x1000>;
clocks = <&cpu_clk 3>;
clock-names = "cpu_1x";
clock-ranges;
ttc1_0: ttc1.0 {
status = "disabled";
reg = <0>;
interrupts = <0 37 4>;
};
ttc1_1: ttc1.1 {
status = "disabled";
reg = <1>;
interrupts = <0 38 4>;
};
ttc1_2: ttc1.2 {
status = "disabled";
reg = <2>;
interrupts = <0 39 4>;
};
};
};
};
......@@ -32,3 +32,13 @@ chosen {
&ps_clk {
clock-frequency = <33333330>;
};
&ttc0_0 {
status = "ok";
compatible = "xlnx,ttc-counter-clocksource";
};
&ttc0_1 {
status = "ok";
compatible = "xlnx,ttc-counter-clockevent";
};
......@@ -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
......@@ -77,8 +66,22 @@ struct xttcpss_timer {
void __iomem *base_addr;
};
static struct xttcpss_timer timers[2];
static struct clock_event_device xttcpss_clockevent;
struct xttcpss_timer_clocksource {
struct xttcpss_timer xttc;
struct clocksource cs;
};
#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", &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", &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);
struct device_node *np;
/* Calculate the parameters to allow the clockevent to operate using
integer math
*/
clockevents_calc_mult_shift(&xttcpss_clockevent, TIMER_RATE, 4);
for_each_compatible_node(np, NULL, "xlnx,ttc") {
struct device_node *np_chld;
void __iomem *base;
xttcpss_clockevent.max_delta_ns =
clockevent_delta2ns(0xfffe, &xttcpss_clockevent);
xttcpss_clockevent.min_delta_ns =
clockevent_delta2ns(1, &xttcpss_clockevent);
base = of_iomap(np, 0);
if (WARN_ON(!base))
return;
/* Indicate that clock event is on 1st CPU as SMP boot needs it */
for_each_available_child_of_node(np, np_chld) {
int (*cb)(struct device_node *np, void __iomem *base);
const struct of_device_id *match;
xttcpss_clockevent.cpumask = cpumask_of(0);
clockevents_register_device(&xttcpss_clockevent);
match = of_match_node(zynq_ttc_match, np_chld);
if (match) {
cb = match->data;
cb(np_chld, base);
}
}
}
}
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