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/*
* Copyright (C) 2013 Pengutronix
* Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License version 2 as published by the
* Free Software Foundation.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/clk.h>
#define TIMERn_CTRL 0x00
#define TIMERn_CTRL_PRESC(val) (((val) & 0xf) << 24)
#define TIMERn_CTRL_PRESC_1024 TIMERn_CTRL_PRESC(10)
#define TIMERn_CTRL_CLKSEL(val) (((val) & 0x3) << 16)
#define TIMERn_CTRL_CLKSEL_PRESCHFPERCLK TIMERn_CTRL_CLKSEL(0)
#define TIMERn_CTRL_OSMEN 0x00000010
#define TIMERn_CTRL_MODE(val) (((val) & 0x3) << 0)
#define TIMERn_CTRL_MODE_UP TIMERn_CTRL_MODE(0)
#define TIMERn_CTRL_MODE_DOWN TIMERn_CTRL_MODE(1)
#define TIMERn_CMD 0x04
#define TIMERn_CMD_START 0x00000001
#define TIMERn_CMD_STOP 0x00000002
#define TIMERn_IEN 0x0c
#define TIMERn_IF 0x10
#define TIMERn_IFS 0x14
#define TIMERn_IFC 0x18
#define TIMERn_IRQ_UF 0x00000002
#define TIMERn_TOP 0x1c
#define TIMERn_CNT 0x24
struct efm32_clock_event_ddata {
struct clock_event_device evtdev;
void __iomem *base;
unsigned periodic_top;
};
static int efm32_clock_event_shutdown(struct clock_event_device *evtdev)
{
struct efm32_clock_event_ddata *ddata =
container_of(evtdev, struct efm32_clock_event_ddata, evtdev);
writel_relaxed(TIMERn_CMD_STOP, ddata->base + TIMERn_CMD);
return 0;
}
static int efm32_clock_event_set_oneshot(struct clock_event_device *evtdev)
{
struct efm32_clock_event_ddata *ddata =
container_of(evtdev, struct efm32_clock_event_ddata, evtdev);
writel_relaxed(TIMERn_CMD_STOP, ddata->base + TIMERn_CMD);
writel_relaxed(TIMERn_CTRL_PRESC_1024 |
TIMERn_CTRL_CLKSEL_PRESCHFPERCLK |
TIMERn_CTRL_OSMEN |
TIMERn_CTRL_MODE_DOWN,
ddata->base + TIMERn_CTRL);
return 0;
}
static int efm32_clock_event_set_periodic(struct clock_event_device *evtdev)
{
struct efm32_clock_event_ddata *ddata =
container_of(evtdev, struct efm32_clock_event_ddata, evtdev);
writel_relaxed(TIMERn_CMD_STOP, ddata->base + TIMERn_CMD);
writel_relaxed(ddata->periodic_top, ddata->base + TIMERn_TOP);
writel_relaxed(TIMERn_CTRL_PRESC_1024 |
TIMERn_CTRL_CLKSEL_PRESCHFPERCLK |
TIMERn_CTRL_MODE_DOWN,
ddata->base + TIMERn_CTRL);
writel_relaxed(TIMERn_CMD_START, ddata->base + TIMERn_CMD);
return 0;
}
static int efm32_clock_event_set_next_event(unsigned long evt,
struct clock_event_device *evtdev)
{
struct efm32_clock_event_ddata *ddata =
container_of(evtdev, struct efm32_clock_event_ddata, evtdev);
writel_relaxed(TIMERn_CMD_STOP, ddata->base + TIMERn_CMD);
writel_relaxed(evt, ddata->base + TIMERn_CNT);
writel_relaxed(TIMERn_CMD_START, ddata->base + TIMERn_CMD);
return 0;
}
static irqreturn_t efm32_clock_event_handler(int irq, void *dev_id)
{
struct efm32_clock_event_ddata *ddata = dev_id;
writel_relaxed(TIMERn_IRQ_UF, ddata->base + TIMERn_IFC);
ddata->evtdev.event_handler(&ddata->evtdev);
return IRQ_HANDLED;
}
static struct efm32_clock_event_ddata clock_event_ddata = {
.evtdev = {
.name = "efm32 clockevent",
.features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
.set_state_shutdown = efm32_clock_event_shutdown,
.set_state_periodic = efm32_clock_event_set_periodic,
.set_state_oneshot = efm32_clock_event_set_oneshot,
.set_next_event = efm32_clock_event_set_next_event,
.rating = 200,
},
};
static struct irqaction efm32_clock_event_irq = {
.name = "efm32 clockevent",
.flags = IRQF_TIMER,
.handler = efm32_clock_event_handler,
.dev_id = &clock_event_ddata,
};
static int __init efm32_clocksource_init(struct device_node *np)
{
struct clk *clk;
void __iomem *base;
unsigned long rate;
int ret;
clk = of_clk_get(np, 0);
if (IS_ERR(clk)) {
ret = PTR_ERR(clk);
pr_err("failed to get clock for clocksource (%d)\n", ret);
goto err_clk_get;
}
ret = clk_prepare_enable(clk);
if (ret) {
pr_err("failed to enable timer clock for clocksource (%d)\n",
ret);
goto err_clk_enable;
}
rate = clk_get_rate(clk);
base = of_iomap(np, 0);
if (!base) {
ret = -EADDRNOTAVAIL;
pr_err("failed to map registers for clocksource\n");
goto err_iomap;
}
writel_relaxed(TIMERn_CTRL_PRESC_1024 |
TIMERn_CTRL_CLKSEL_PRESCHFPERCLK |
TIMERn_CTRL_MODE_UP, base + TIMERn_CTRL);
writel_relaxed(TIMERn_CMD_START, base + TIMERn_CMD);
ret = clocksource_mmio_init(base + TIMERn_CNT, "efm32 timer",
DIV_ROUND_CLOSEST(rate, 1024), 200, 16,
clocksource_mmio_readl_up);
if (ret) {
pr_err("failed to init clocksource (%d)\n", ret);
goto err_clocksource_init;
}
return 0;
err_clocksource_init:
iounmap(base);
err_iomap:
clk_disable_unprepare(clk);
err_clk_enable:
clk_put(clk);
err_clk_get:
return ret;
}
static int __init efm32_clockevent_init(struct device_node *np)
{
struct clk *clk;
void __iomem *base;
unsigned long rate;
int irq;
int ret;
clk = of_clk_get(np, 0);
if (IS_ERR(clk)) {
ret = PTR_ERR(clk);
pr_err("failed to get clock for clockevent (%d)\n", ret);
goto err_clk_get;
}
ret = clk_prepare_enable(clk);
if (ret) {
pr_err("failed to enable timer clock for clockevent (%d)\n",
ret);
goto err_clk_enable;
}
rate = clk_get_rate(clk);
base = of_iomap(np, 0);
if (!base) {
ret = -EADDRNOTAVAIL;
pr_err("failed to map registers for clockevent\n");
goto err_iomap;
}
irq = irq_of_parse_and_map(np, 0);
if (!irq) {
ret = -ENOENT;
pr_err("failed to get irq for clockevent\n");
goto err_get_irq;
}
writel_relaxed(TIMERn_IRQ_UF, base + TIMERn_IEN);
clock_event_ddata.base = base;
clock_event_ddata.periodic_top = DIV_ROUND_CLOSEST(rate, 1024 * HZ);
clockevents_config_and_register(&clock_event_ddata.evtdev,
DIV_ROUND_CLOSEST(rate, 1024),
0xf, 0xffff);
setup_irq(irq, &efm32_clock_event_irq);
return 0;
err_get_irq:
iounmap(base);
err_iomap:
clk_disable_unprepare(clk);
err_clk_enable:
clk_put(clk);
err_clk_get:
return ret;
}
/*
* This function asserts that we have exactly one clocksource and one
* clock_event_device in the end.
*/
static void __init efm32_timer_init(struct device_node *np)
{
static int has_clocksource, has_clockevent;
int ret;
if (!has_clocksource) {
ret = efm32_clocksource_init(np);
if (!ret) {
has_clocksource = 1;
return;
}
}
if (!has_clockevent) {
ret = efm32_clockevent_init(np);
if (!ret) {
has_clockevent = 1;
return;
}
}
}
CLOCKSOURCE_OF_DECLARE(efm32compat, "efm32,timer", efm32_timer_init);
CLOCKSOURCE_OF_DECLARE(efm32, "energymicro,efm32-timer", efm32_timer_init);
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