OpenCloudOS-Kernel/drivers/clocksource/sh_tmu.c

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/*
* SuperH Timer Support - TMU
*
* Copyright (C) 2009 Magnus Damm
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/clk.h>
#include <linux/clockchips.h>
#include <linux/clocksource.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
#include <linux/sh_timer.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
enum sh_tmu_model {
SH_TMU,
SH_TMU_SH3,
};
struct sh_tmu_device;
struct sh_tmu_channel {
struct sh_tmu_device *tmu;
unsigned int index;
void __iomem *base;
int irq;
unsigned long periodic;
struct clock_event_device ced;
struct clocksource cs;
bool cs_enabled;
unsigned int enable_count;
};
struct sh_tmu_device {
struct platform_device *pdev;
void __iomem *mapbase;
struct clk *clk;
clocksource: sh_tmu: Compute rate before registration again With the upcoming NTP correction related rate adjustments to be implemented in the clockevents core, the latter needs to get informed about every rate change of a clockevent device made after its registration. Currently, sh_tmu violates this requirement in that it registers its clockevent device with a dummy rate and sets its final rate through clockevents_config() called from its ->set_state_oneshot() and ->set_state_periodic() functions respectively. This patch moves the setting of the clockevent device's rate to its registration. Note that there has been some back and forth regarding this question with respect to the clocksource also provided by this driver: commit 66f49121ffa4 ("clocksource: sh_tmu: compute mult and shift before registration") moves the rate determination from the clocksource's ->enable() function to before its registration. OTOH, the later commit 0aeac458d9eb ("clocksource: sh_tmu: __clocksource_updatefreq_hz() update") basically reverts this, saying "Without this patch the old code uses clocksource_register() together with a hack that assumes a never changing clock rate." However, I checked all current sh_tmu users in arch/sh as well as in arch/arm/mach-shmobile carefully and right now, none of them changes any rate in any clock tree relevant to sh_tmu after their respective time_init(). Since all sh_tmu instances are created after time_init(), none of them should ever observe any clock rate changes. What's more, both, a clocksource as well as a clockevent device, can immediately get selected for use at their registration and thus, enabled at this point already. So it's probably safer to assume a "never changing clock rate" here. - Move the struct sh_tmu_channel's ->rate member to struct sh_tmu_device: it's a property of the underlying clock which is in turn specific to the sh_tmu_device. - Determine the ->rate value in sh_tmu_setup() at device probing rather than at first usage. - Set the clockevent device's rate at its registration. - Although not strictly necessary for the upcoming clockevent core changes, set the clocksource's rate at its registration for consistency. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-02-07 05:12:00 +08:00
unsigned long rate;
enum sh_tmu_model model;
raw_spinlock_t lock; /* Protect the shared start/stop register */
struct sh_tmu_channel *channels;
unsigned int num_channels;
bool has_clockevent;
bool has_clocksource;
};
#define TSTR -1 /* shared register */
#define TCOR 0 /* channel register */
#define TCNT 1 /* channel register */
#define TCR 2 /* channel register */
#define TCR_UNF (1 << 8)
#define TCR_UNIE (1 << 5)
#define TCR_TPSC_CLK4 (0 << 0)
#define TCR_TPSC_CLK16 (1 << 0)
#define TCR_TPSC_CLK64 (2 << 0)
#define TCR_TPSC_CLK256 (3 << 0)
#define TCR_TPSC_CLK1024 (4 << 0)
#define TCR_TPSC_MASK (7 << 0)
static inline unsigned long sh_tmu_read(struct sh_tmu_channel *ch, int reg_nr)
{
unsigned long offs;
if (reg_nr == TSTR) {
switch (ch->tmu->model) {
case SH_TMU_SH3:
return ioread8(ch->tmu->mapbase + 2);
case SH_TMU:
return ioread8(ch->tmu->mapbase + 4);
}
}
offs = reg_nr << 2;
if (reg_nr == TCR)
return ioread16(ch->base + offs);
else
return ioread32(ch->base + offs);
}
static inline void sh_tmu_write(struct sh_tmu_channel *ch, int reg_nr,
unsigned long value)
{
unsigned long offs;
if (reg_nr == TSTR) {
switch (ch->tmu->model) {
case SH_TMU_SH3:
return iowrite8(value, ch->tmu->mapbase + 2);
case SH_TMU:
return iowrite8(value, ch->tmu->mapbase + 4);
}
}
offs = reg_nr << 2;
if (reg_nr == TCR)
iowrite16(value, ch->base + offs);
else
iowrite32(value, ch->base + offs);
}
static void sh_tmu_start_stop_ch(struct sh_tmu_channel *ch, int start)
{
unsigned long flags, value;
/* start stop register shared by multiple timer channels */
raw_spin_lock_irqsave(&ch->tmu->lock, flags);
value = sh_tmu_read(ch, TSTR);
if (start)
value |= 1 << ch->index;
else
value &= ~(1 << ch->index);
sh_tmu_write(ch, TSTR, value);
raw_spin_unlock_irqrestore(&ch->tmu->lock, flags);
}
static int __sh_tmu_enable(struct sh_tmu_channel *ch)
{
int ret;
/* enable clock */
ret = clk_enable(ch->tmu->clk);
if (ret) {
dev_err(&ch->tmu->pdev->dev, "ch%u: cannot enable clock\n",
ch->index);
return ret;
}
/* make sure channel is disabled */
sh_tmu_start_stop_ch(ch, 0);
/* maximum timeout */
sh_tmu_write(ch, TCOR, 0xffffffff);
sh_tmu_write(ch, TCNT, 0xffffffff);
/* configure channel to parent clock / 4, irq off */
sh_tmu_write(ch, TCR, TCR_TPSC_CLK4);
/* enable channel */
sh_tmu_start_stop_ch(ch, 1);
return 0;
}
static int sh_tmu_enable(struct sh_tmu_channel *ch)
{
if (ch->enable_count++ > 0)
return 0;
pm_runtime_get_sync(&ch->tmu->pdev->dev);
dev_pm_syscore_device(&ch->tmu->pdev->dev, true);
return __sh_tmu_enable(ch);
}
static void __sh_tmu_disable(struct sh_tmu_channel *ch)
{
/* disable channel */
sh_tmu_start_stop_ch(ch, 0);
/* disable interrupts in TMU block */
sh_tmu_write(ch, TCR, TCR_TPSC_CLK4);
/* stop clock */
clk_disable(ch->tmu->clk);
}
static void sh_tmu_disable(struct sh_tmu_channel *ch)
{
if (WARN_ON(ch->enable_count == 0))
return;
if (--ch->enable_count > 0)
return;
__sh_tmu_disable(ch);
dev_pm_syscore_device(&ch->tmu->pdev->dev, false);
pm_runtime_put(&ch->tmu->pdev->dev);
}
static void sh_tmu_set_next(struct sh_tmu_channel *ch, unsigned long delta,
int periodic)
{
/* stop timer */
sh_tmu_start_stop_ch(ch, 0);
/* acknowledge interrupt */
sh_tmu_read(ch, TCR);
/* enable interrupt */
sh_tmu_write(ch, TCR, TCR_UNIE | TCR_TPSC_CLK4);
/* reload delta value in case of periodic timer */
if (periodic)
sh_tmu_write(ch, TCOR, delta);
else
sh_tmu_write(ch, TCOR, 0xffffffff);
sh_tmu_write(ch, TCNT, delta);
/* start timer */
sh_tmu_start_stop_ch(ch, 1);
}
static irqreturn_t sh_tmu_interrupt(int irq, void *dev_id)
{
struct sh_tmu_channel *ch = dev_id;
/* disable or acknowledge interrupt */
if (clockevent_state_oneshot(&ch->ced))
sh_tmu_write(ch, TCR, TCR_TPSC_CLK4);
else
sh_tmu_write(ch, TCR, TCR_UNIE | TCR_TPSC_CLK4);
/* notify clockevent layer */
ch->ced.event_handler(&ch->ced);
return IRQ_HANDLED;
}
static struct sh_tmu_channel *cs_to_sh_tmu(struct clocksource *cs)
{
return container_of(cs, struct sh_tmu_channel, cs);
}
static u64 sh_tmu_clocksource_read(struct clocksource *cs)
{
struct sh_tmu_channel *ch = cs_to_sh_tmu(cs);
return sh_tmu_read(ch, TCNT) ^ 0xffffffff;
}
static int sh_tmu_clocksource_enable(struct clocksource *cs)
{
struct sh_tmu_channel *ch = cs_to_sh_tmu(cs);
int ret;
if (WARN_ON(ch->cs_enabled))
return 0;
ret = sh_tmu_enable(ch);
clocksource: sh_tmu: Compute rate before registration again With the upcoming NTP correction related rate adjustments to be implemented in the clockevents core, the latter needs to get informed about every rate change of a clockevent device made after its registration. Currently, sh_tmu violates this requirement in that it registers its clockevent device with a dummy rate and sets its final rate through clockevents_config() called from its ->set_state_oneshot() and ->set_state_periodic() functions respectively. This patch moves the setting of the clockevent device's rate to its registration. Note that there has been some back and forth regarding this question with respect to the clocksource also provided by this driver: commit 66f49121ffa4 ("clocksource: sh_tmu: compute mult and shift before registration") moves the rate determination from the clocksource's ->enable() function to before its registration. OTOH, the later commit 0aeac458d9eb ("clocksource: sh_tmu: __clocksource_updatefreq_hz() update") basically reverts this, saying "Without this patch the old code uses clocksource_register() together with a hack that assumes a never changing clock rate." However, I checked all current sh_tmu users in arch/sh as well as in arch/arm/mach-shmobile carefully and right now, none of them changes any rate in any clock tree relevant to sh_tmu after their respective time_init(). Since all sh_tmu instances are created after time_init(), none of them should ever observe any clock rate changes. What's more, both, a clocksource as well as a clockevent device, can immediately get selected for use at their registration and thus, enabled at this point already. So it's probably safer to assume a "never changing clock rate" here. - Move the struct sh_tmu_channel's ->rate member to struct sh_tmu_device: it's a property of the underlying clock which is in turn specific to the sh_tmu_device. - Determine the ->rate value in sh_tmu_setup() at device probing rather than at first usage. - Set the clockevent device's rate at its registration. - Although not strictly necessary for the upcoming clockevent core changes, set the clocksource's rate at its registration for consistency. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-02-07 05:12:00 +08:00
if (!ret)
ch->cs_enabled = true;
return ret;
}
static void sh_tmu_clocksource_disable(struct clocksource *cs)
{
struct sh_tmu_channel *ch = cs_to_sh_tmu(cs);
if (WARN_ON(!ch->cs_enabled))
return;
sh_tmu_disable(ch);
ch->cs_enabled = false;
}
static void sh_tmu_clocksource_suspend(struct clocksource *cs)
{
struct sh_tmu_channel *ch = cs_to_sh_tmu(cs);
if (!ch->cs_enabled)
return;
if (--ch->enable_count == 0) {
__sh_tmu_disable(ch);
pm_genpd_syscore_poweroff(&ch->tmu->pdev->dev);
}
}
static void sh_tmu_clocksource_resume(struct clocksource *cs)
{
struct sh_tmu_channel *ch = cs_to_sh_tmu(cs);
if (!ch->cs_enabled)
return;
if (ch->enable_count++ == 0) {
pm_genpd_syscore_poweron(&ch->tmu->pdev->dev);
__sh_tmu_enable(ch);
}
}
static int sh_tmu_register_clocksource(struct sh_tmu_channel *ch,
const char *name)
{
struct clocksource *cs = &ch->cs;
cs->name = name;
cs->rating = 200;
cs->read = sh_tmu_clocksource_read;
cs->enable = sh_tmu_clocksource_enable;
cs->disable = sh_tmu_clocksource_disable;
cs->suspend = sh_tmu_clocksource_suspend;
cs->resume = sh_tmu_clocksource_resume;
cs->mask = CLOCKSOURCE_MASK(32);
cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
dev_info(&ch->tmu->pdev->dev, "ch%u: used as clock source\n",
ch->index);
clocksource: sh_tmu: Compute rate before registration again With the upcoming NTP correction related rate adjustments to be implemented in the clockevents core, the latter needs to get informed about every rate change of a clockevent device made after its registration. Currently, sh_tmu violates this requirement in that it registers its clockevent device with a dummy rate and sets its final rate through clockevents_config() called from its ->set_state_oneshot() and ->set_state_periodic() functions respectively. This patch moves the setting of the clockevent device's rate to its registration. Note that there has been some back and forth regarding this question with respect to the clocksource also provided by this driver: commit 66f49121ffa4 ("clocksource: sh_tmu: compute mult and shift before registration") moves the rate determination from the clocksource's ->enable() function to before its registration. OTOH, the later commit 0aeac458d9eb ("clocksource: sh_tmu: __clocksource_updatefreq_hz() update") basically reverts this, saying "Without this patch the old code uses clocksource_register() together with a hack that assumes a never changing clock rate." However, I checked all current sh_tmu users in arch/sh as well as in arch/arm/mach-shmobile carefully and right now, none of them changes any rate in any clock tree relevant to sh_tmu after their respective time_init(). Since all sh_tmu instances are created after time_init(), none of them should ever observe any clock rate changes. What's more, both, a clocksource as well as a clockevent device, can immediately get selected for use at their registration and thus, enabled at this point already. So it's probably safer to assume a "never changing clock rate" here. - Move the struct sh_tmu_channel's ->rate member to struct sh_tmu_device: it's a property of the underlying clock which is in turn specific to the sh_tmu_device. - Determine the ->rate value in sh_tmu_setup() at device probing rather than at first usage. - Set the clockevent device's rate at its registration. - Although not strictly necessary for the upcoming clockevent core changes, set the clocksource's rate at its registration for consistency. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-02-07 05:12:00 +08:00
clocksource_register_hz(cs, ch->tmu->rate);
return 0;
}
static struct sh_tmu_channel *ced_to_sh_tmu(struct clock_event_device *ced)
{
return container_of(ced, struct sh_tmu_channel, ced);
}
static void sh_tmu_clock_event_start(struct sh_tmu_channel *ch, int periodic)
{
sh_tmu_enable(ch);
if (periodic) {
clocksource: sh_tmu: Compute rate before registration again With the upcoming NTP correction related rate adjustments to be implemented in the clockevents core, the latter needs to get informed about every rate change of a clockevent device made after its registration. Currently, sh_tmu violates this requirement in that it registers its clockevent device with a dummy rate and sets its final rate through clockevents_config() called from its ->set_state_oneshot() and ->set_state_periodic() functions respectively. This patch moves the setting of the clockevent device's rate to its registration. Note that there has been some back and forth regarding this question with respect to the clocksource also provided by this driver: commit 66f49121ffa4 ("clocksource: sh_tmu: compute mult and shift before registration") moves the rate determination from the clocksource's ->enable() function to before its registration. OTOH, the later commit 0aeac458d9eb ("clocksource: sh_tmu: __clocksource_updatefreq_hz() update") basically reverts this, saying "Without this patch the old code uses clocksource_register() together with a hack that assumes a never changing clock rate." However, I checked all current sh_tmu users in arch/sh as well as in arch/arm/mach-shmobile carefully and right now, none of them changes any rate in any clock tree relevant to sh_tmu after their respective time_init(). Since all sh_tmu instances are created after time_init(), none of them should ever observe any clock rate changes. What's more, both, a clocksource as well as a clockevent device, can immediately get selected for use at their registration and thus, enabled at this point already. So it's probably safer to assume a "never changing clock rate" here. - Move the struct sh_tmu_channel's ->rate member to struct sh_tmu_device: it's a property of the underlying clock which is in turn specific to the sh_tmu_device. - Determine the ->rate value in sh_tmu_setup() at device probing rather than at first usage. - Set the clockevent device's rate at its registration. - Although not strictly necessary for the upcoming clockevent core changes, set the clocksource's rate at its registration for consistency. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-02-07 05:12:00 +08:00
ch->periodic = (ch->tmu->rate + HZ/2) / HZ;
sh_tmu_set_next(ch, ch->periodic, 1);
}
}
static int sh_tmu_clock_event_shutdown(struct clock_event_device *ced)
{
struct sh_tmu_channel *ch = ced_to_sh_tmu(ced);
clocksource/drivers/sh_tmu: Fix traceback spotted in -next Traceback in -next due to commit 'clockevents/drivers/sh_tmu: Migrate to new 'set-state' interface'. Commit ("clockevents/drivers/sh_tmu: Migrate to new 'set-state' interface") in -next causes the following traceback. This is seen with qemu runs for the sh target. ------------[ cut here ]------------ WARNING: at drivers/clocksource/sh_tmu.c:202 Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 4.2.0-rc3-next-20150720 #1 task: 8c411ed8 ti: 8c40e000 task.ti: 8c40e000 PC is at sh_tmu_disable+0x40/0x60 PR is at sh_tmu_clock_event_shutdown+0x8/0x20 PC : 8c271220 SP : 8c40ff10 SR : 400081f1 TEA : 00000000 R0 : 8c271240 R1 : 8fc08cfc R2 : 00000000 R3 : 3fffffff R4 : 8fc08c00 R5 : 00000001 R6 : 00000002 R7 : ffffffff R8 : 00000001 R9 : 8fc08c20 R10 : 00000000 R11 : 00000000 R12 : 8c012820 R13 : 00000000 R14 : 00000000 MACH: 3b9ac9ff MACL: 80000000 GBR : 00000000 PR : 8c271248 Call trace: [<8c065836>] clockevents_switch_state+0x16/0x60 [<8c06588c>] clockevents_shutdown+0xc/0x40 [<8c066330>] tick_check_new_device+0x90/0xc0 [<8c065556>] clockevents_register_device+0x56/0x120 [<8c0662a0>] tick_check_new_device+0x0/0xc0 [<8c27167a>] sh_tmu_probe+0x29a/0x4e0 [<8c18a994>] kasprintf+0x14/0x20 [<8c442782>] early_platform_driver_probe+0x20e/0x2bc [<8c1fade0>] platform_match+0x0/0x100 [<8c33babc>] printk+0x0/0x24 [<8c434892>] start_kernel+0x32e/0x574 [<8c33babc>] printk+0x0/0x24 [<8c17d320>] strlen+0x0/0x58 [<8c43430c>] unknown_bootoption+0x0/0x1e0 [<8c011024>] _stext+0x24/0x30 ---[ end trace cb88537fdc8fa200 ]--- Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
2015-07-21 10:31:14 +08:00
if (clockevent_state_oneshot(ced) || clockevent_state_periodic(ced))
sh_tmu_disable(ch);
return 0;
}
static int sh_tmu_clock_event_set_state(struct clock_event_device *ced,
int periodic)
{
struct sh_tmu_channel *ch = ced_to_sh_tmu(ced);
/* deal with old setting first */
if (clockevent_state_oneshot(ced) || clockevent_state_periodic(ced))
sh_tmu_disable(ch);
dev_info(&ch->tmu->pdev->dev, "ch%u: used for %s clock events\n",
ch->index, periodic ? "periodic" : "oneshot");
sh_tmu_clock_event_start(ch, periodic);
return 0;
}
static int sh_tmu_clock_event_set_oneshot(struct clock_event_device *ced)
{
return sh_tmu_clock_event_set_state(ced, 0);
}
static int sh_tmu_clock_event_set_periodic(struct clock_event_device *ced)
{
return sh_tmu_clock_event_set_state(ced, 1);
}
static int sh_tmu_clock_event_next(unsigned long delta,
struct clock_event_device *ced)
{
struct sh_tmu_channel *ch = ced_to_sh_tmu(ced);
BUG_ON(!clockevent_state_oneshot(ced));
/* program new delta value */
sh_tmu_set_next(ch, delta, 0);
return 0;
}
static void sh_tmu_clock_event_suspend(struct clock_event_device *ced)
{
pm_genpd_syscore_poweroff(&ced_to_sh_tmu(ced)->tmu->pdev->dev);
}
static void sh_tmu_clock_event_resume(struct clock_event_device *ced)
{
pm_genpd_syscore_poweron(&ced_to_sh_tmu(ced)->tmu->pdev->dev);
}
static void sh_tmu_register_clockevent(struct sh_tmu_channel *ch,
const char *name)
{
struct clock_event_device *ced = &ch->ced;
int ret;
ced->name = name;
ced->features = CLOCK_EVT_FEAT_PERIODIC;
ced->features |= CLOCK_EVT_FEAT_ONESHOT;
ced->rating = 200;
ced->cpumask = cpu_possible_mask;
ced->set_next_event = sh_tmu_clock_event_next;
ced->set_state_shutdown = sh_tmu_clock_event_shutdown;
ced->set_state_periodic = sh_tmu_clock_event_set_periodic;
ced->set_state_oneshot = sh_tmu_clock_event_set_oneshot;
ced->suspend = sh_tmu_clock_event_suspend;
ced->resume = sh_tmu_clock_event_resume;
dev_info(&ch->tmu->pdev->dev, "ch%u: used for clock events\n",
ch->index);
clocksource: sh_tmu: Compute rate before registration again With the upcoming NTP correction related rate adjustments to be implemented in the clockevents core, the latter needs to get informed about every rate change of a clockevent device made after its registration. Currently, sh_tmu violates this requirement in that it registers its clockevent device with a dummy rate and sets its final rate through clockevents_config() called from its ->set_state_oneshot() and ->set_state_periodic() functions respectively. This patch moves the setting of the clockevent device's rate to its registration. Note that there has been some back and forth regarding this question with respect to the clocksource also provided by this driver: commit 66f49121ffa4 ("clocksource: sh_tmu: compute mult and shift before registration") moves the rate determination from the clocksource's ->enable() function to before its registration. OTOH, the later commit 0aeac458d9eb ("clocksource: sh_tmu: __clocksource_updatefreq_hz() update") basically reverts this, saying "Without this patch the old code uses clocksource_register() together with a hack that assumes a never changing clock rate." However, I checked all current sh_tmu users in arch/sh as well as in arch/arm/mach-shmobile carefully and right now, none of them changes any rate in any clock tree relevant to sh_tmu after their respective time_init(). Since all sh_tmu instances are created after time_init(), none of them should ever observe any clock rate changes. What's more, both, a clocksource as well as a clockevent device, can immediately get selected for use at their registration and thus, enabled at this point already. So it's probably safer to assume a "never changing clock rate" here. - Move the struct sh_tmu_channel's ->rate member to struct sh_tmu_device: it's a property of the underlying clock which is in turn specific to the sh_tmu_device. - Determine the ->rate value in sh_tmu_setup() at device probing rather than at first usage. - Set the clockevent device's rate at its registration. - Although not strictly necessary for the upcoming clockevent core changes, set the clocksource's rate at its registration for consistency. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-02-07 05:12:00 +08:00
clockevents_config_and_register(ced, ch->tmu->rate, 0x300, 0xffffffff);
ret = request_irq(ch->irq, sh_tmu_interrupt,
IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
dev_name(&ch->tmu->pdev->dev), ch);
if (ret) {
dev_err(&ch->tmu->pdev->dev, "ch%u: failed to request irq %d\n",
ch->index, ch->irq);
return;
}
}
static int sh_tmu_register(struct sh_tmu_channel *ch, const char *name,
bool clockevent, bool clocksource)
{
if (clockevent) {
ch->tmu->has_clockevent = true;
sh_tmu_register_clockevent(ch, name);
} else if (clocksource) {
ch->tmu->has_clocksource = true;
sh_tmu_register_clocksource(ch, name);
}
return 0;
}
static int sh_tmu_channel_setup(struct sh_tmu_channel *ch, unsigned int index,
bool clockevent, bool clocksource,
struct sh_tmu_device *tmu)
{
/* Skip unused channels. */
if (!clockevent && !clocksource)
return 0;
ch->tmu = tmu;
ch->index = index;
if (tmu->model == SH_TMU_SH3)
ch->base = tmu->mapbase + 4 + ch->index * 12;
else
ch->base = tmu->mapbase + 8 + ch->index * 12;
ch->irq = platform_get_irq(tmu->pdev, index);
if (ch->irq < 0) {
dev_err(&tmu->pdev->dev, "ch%u: failed to get irq\n",
ch->index);
return ch->irq;
}
ch->cs_enabled = false;
ch->enable_count = 0;
return sh_tmu_register(ch, dev_name(&tmu->pdev->dev),
clockevent, clocksource);
}
static int sh_tmu_map_memory(struct sh_tmu_device *tmu)
{
struct resource *res;
res = platform_get_resource(tmu->pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&tmu->pdev->dev, "failed to get I/O memory\n");
return -ENXIO;
}
tmu->mapbase = ioremap_nocache(res->start, resource_size(res));
if (tmu->mapbase == NULL)
return -ENXIO;
return 0;
}
static int sh_tmu_parse_dt(struct sh_tmu_device *tmu)
{
struct device_node *np = tmu->pdev->dev.of_node;
tmu->model = SH_TMU;
tmu->num_channels = 3;
of_property_read_u32(np, "#renesas,channels", &tmu->num_channels);
if (tmu->num_channels != 2 && tmu->num_channels != 3) {
dev_err(&tmu->pdev->dev, "invalid number of channels %u\n",
tmu->num_channels);
return -EINVAL;
}
return 0;
}
static int sh_tmu_setup(struct sh_tmu_device *tmu, struct platform_device *pdev)
{
unsigned int i;
int ret;
tmu->pdev = pdev;
raw_spin_lock_init(&tmu->lock);
if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) {
ret = sh_tmu_parse_dt(tmu);
if (ret < 0)
return ret;
} else if (pdev->dev.platform_data) {
const struct platform_device_id *id = pdev->id_entry;
struct sh_timer_config *cfg = pdev->dev.platform_data;
tmu->model = id->driver_data;
tmu->num_channels = hweight8(cfg->channels_mask);
} else {
dev_err(&tmu->pdev->dev, "missing platform data\n");
return -ENXIO;
}
/* Get hold of clock. */
tmu->clk = clk_get(&tmu->pdev->dev, "fck");
if (IS_ERR(tmu->clk)) {
dev_err(&tmu->pdev->dev, "cannot get clock\n");
return PTR_ERR(tmu->clk);
}
ret = clk_prepare(tmu->clk);
if (ret < 0)
goto err_clk_put;
clocksource: sh_tmu: Compute rate before registration again With the upcoming NTP correction related rate adjustments to be implemented in the clockevents core, the latter needs to get informed about every rate change of a clockevent device made after its registration. Currently, sh_tmu violates this requirement in that it registers its clockevent device with a dummy rate and sets its final rate through clockevents_config() called from its ->set_state_oneshot() and ->set_state_periodic() functions respectively. This patch moves the setting of the clockevent device's rate to its registration. Note that there has been some back and forth regarding this question with respect to the clocksource also provided by this driver: commit 66f49121ffa4 ("clocksource: sh_tmu: compute mult and shift before registration") moves the rate determination from the clocksource's ->enable() function to before its registration. OTOH, the later commit 0aeac458d9eb ("clocksource: sh_tmu: __clocksource_updatefreq_hz() update") basically reverts this, saying "Without this patch the old code uses clocksource_register() together with a hack that assumes a never changing clock rate." However, I checked all current sh_tmu users in arch/sh as well as in arch/arm/mach-shmobile carefully and right now, none of them changes any rate in any clock tree relevant to sh_tmu after their respective time_init(). Since all sh_tmu instances are created after time_init(), none of them should ever observe any clock rate changes. What's more, both, a clocksource as well as a clockevent device, can immediately get selected for use at their registration and thus, enabled at this point already. So it's probably safer to assume a "never changing clock rate" here. - Move the struct sh_tmu_channel's ->rate member to struct sh_tmu_device: it's a property of the underlying clock which is in turn specific to the sh_tmu_device. - Determine the ->rate value in sh_tmu_setup() at device probing rather than at first usage. - Set the clockevent device's rate at its registration. - Although not strictly necessary for the upcoming clockevent core changes, set the clocksource's rate at its registration for consistency. Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-02-07 05:12:00 +08:00
/* Determine clock rate. */
ret = clk_enable(tmu->clk);
if (ret < 0)
goto err_clk_unprepare;
tmu->rate = clk_get_rate(tmu->clk) / 4;
clk_disable(tmu->clk);
/* Map the memory resource. */
ret = sh_tmu_map_memory(tmu);
if (ret < 0) {
dev_err(&tmu->pdev->dev, "failed to remap I/O memory\n");
goto err_clk_unprepare;
}
/* Allocate and setup the channels. */
tmu->channels = kzalloc(sizeof(*tmu->channels) * tmu->num_channels,
GFP_KERNEL);
if (tmu->channels == NULL) {
ret = -ENOMEM;
goto err_unmap;
}
/*
* Use the first channel as a clock event device and the second channel
* as a clock source.
*/
for (i = 0; i < tmu->num_channels; ++i) {
ret = sh_tmu_channel_setup(&tmu->channels[i], i,
i == 0, i == 1, tmu);
if (ret < 0)
goto err_unmap;
}
platform_set_drvdata(pdev, tmu);
return 0;
err_unmap:
kfree(tmu->channels);
iounmap(tmu->mapbase);
err_clk_unprepare:
clk_unprepare(tmu->clk);
err_clk_put:
clk_put(tmu->clk);
return ret;
}
static int sh_tmu_probe(struct platform_device *pdev)
{
struct sh_tmu_device *tmu = platform_get_drvdata(pdev);
int ret;
if (!is_early_platform_device(pdev)) {
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);
}
if (tmu) {
dev_info(&pdev->dev, "kept as earlytimer\n");
goto out;
}
tmu = kzalloc(sizeof(*tmu), GFP_KERNEL);
if (tmu == NULL)
return -ENOMEM;
ret = sh_tmu_setup(tmu, pdev);
if (ret) {
kfree(tmu);
pm_runtime_idle(&pdev->dev);
return ret;
}
if (is_early_platform_device(pdev))
return 0;
out:
if (tmu->has_clockevent || tmu->has_clocksource)
pm_runtime_irq_safe(&pdev->dev);
else
pm_runtime_idle(&pdev->dev);
return 0;
}
static int sh_tmu_remove(struct platform_device *pdev)
{
return -EBUSY; /* cannot unregister clockevent and clocksource */
}
static const struct platform_device_id sh_tmu_id_table[] = {
{ "sh-tmu", SH_TMU },
{ "sh-tmu-sh3", SH_TMU_SH3 },
{ }
};
MODULE_DEVICE_TABLE(platform, sh_tmu_id_table);
static const struct of_device_id sh_tmu_of_table[] __maybe_unused = {
{ .compatible = "renesas,tmu" },
{ }
};
MODULE_DEVICE_TABLE(of, sh_tmu_of_table);
static struct platform_driver sh_tmu_device_driver = {
.probe = sh_tmu_probe,
.remove = sh_tmu_remove,
.driver = {
.name = "sh_tmu",
.of_match_table = of_match_ptr(sh_tmu_of_table),
},
.id_table = sh_tmu_id_table,
};
static int __init sh_tmu_init(void)
{
return platform_driver_register(&sh_tmu_device_driver);
}
static void __exit sh_tmu_exit(void)
{
platform_driver_unregister(&sh_tmu_device_driver);
}
early_platform_init("earlytimer", &sh_tmu_device_driver);
subsys_initcall(sh_tmu_init);
module_exit(sh_tmu_exit);
MODULE_AUTHOR("Magnus Damm");
MODULE_DESCRIPTION("SuperH TMU Timer Driver");
MODULE_LICENSE("GPL v2");