Hi,
This series immproves the Atmel TCB clocksource driver to address the
most urgent shortcomings:
- the current tcb_clksrc driver is probed too late to be able to be used at
boot and we now have SoCs that don't have a PIT. They currently are not able
to boot an upstream kernel.
- using the PIT doesn't work well with preempt-rt because its interrupt is
shared (in particular with the UART) and their interrupt flags are
incompatible). This also happen with the threadedirq command line
switch.
- there is currently no high resolution sched_clock.
The plan is to get those changes upstream as soon as possible as they are fixing
real issues that people are facing. There are further changes needed on the
clocksource driver to try to stop wasting a TCB channel.
The PWM TCB driver will also be changed to actually use the reviewed binding
and this will allow to get rid of atmel_tclib.
Changes in v2:
- collected acks from Thierry and Arnd
- dropped most of the atmel_tclib changes that coud be separated.
- added a patch from kbuild
- dropped the patch removing the PIT from the defconfig
- moved the atmel_tcb.h inclusion in drivers/pwm/pwm-atmel-tcb.c as requested
by Thierry
- stopped using atmel_tcb_config
- reworked the irq number parsing to only care for channel 2
Alexandre Belloni (8):
ARM: at91: move SoC specific definitions to SoC folder
clocksource/drivers/tcb_clksrc: stop depending on atmel_tclib
clocksource/drivers/tcb_clksrc: Use tcb as sched_clock
ARM: at91: Implement clocksource selection
clocksource/drivers/tcb_clksrc: move Kconfig option
clocksource/drivers/timer-atmel-pit: rework Kconfig option
clocksource/drivers/tcb_clksrc: Rename the file for consistency
misc: atmel_tclib: do not probe already used TCBs
kbuild test robot (1):
clocksource/drivers/timer-atmel-tcb: tc_clksrc_suspend() can be static
arch/arm/mach-at91/Kconfig | 23 ++++
drivers/clocksource/Kconfig | 12 +-
drivers/clocksource/Makefile | 2 +-
.../{tcb_clksrc.c => timer-atmel-tcb.c} | 130 ++++++++++++------
drivers/misc/Kconfig | 24 ----
drivers/misc/atmel_tclib.c | 5 +-
drivers/pwm/pwm-atmel-tcb.c | 2 +-
.../atmel_tc.h => soc/at91/atmel_tcb.h} | 4 +-
8 files changed, 129 insertions(+), 73 deletions(-)
rename drivers/clocksource/{tcb_clksrc.c => timer-atmel-tcb.c} (79%)
rename include/{linux/atmel_tc.h => soc/at91/atmel_tcb.h} (99%)
--
2.20.1
atmel_tclib is probed too late in the boot process to be able to use the
TCB as the boot clocksource. This is an issue for SoCs without the PIT
(sams70, samv70 and samv71 families) as they simply currently can't boot.
Get rid of the atmel_tclib dependency and probe everything on our own using
the correct device tree binding.
This also allows getting rid of ATMEL_TCB_CLKSRC_BLOCK and makes the driver
a bit more flexible as the TCB is not hardcoded in the kernel anymore.
Signed-off-by: Alexandre Belloni <[email protected]>
---
drivers/clocksource/tcb_clksrc.c | 108 +++++++++++++++++++------------
drivers/misc/Kconfig | 14 +---
2 files changed, 70 insertions(+), 52 deletions(-)
diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 138a12090149..bf68504da94a 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -9,7 +9,8 @@
#include <linux/err.h>
#include <linux/ioport.h>
#include <linux/io.h>
-#include <linux/platform_device.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
#include <linux/syscore_ops.h>
#include <soc/at91/atmel_tcb.h>
@@ -28,13 +29,6 @@
* source, used in either periodic or oneshot mode. This runs
* at 32 KiHZ, and can handle delays of up to two seconds.
*
- * A boot clocksource and clockevent source are also currently needed,
- * unless the relevant platforms (ARM/AT91, AVR32/AT32) are changed so
- * this code can be used when init_timers() is called, well before most
- * devices are set up. (Some low end AT91 parts, which can run uClinux,
- * have only the timers in one TC block... they currently don't support
- * the tclib code, because of that initialization issue.)
- *
* REVISIT behavior during system suspend states... we should disable
* all clocks and save the power. Easily done for clockevent devices,
* but clocksources won't necessarily get the needed notifications.
@@ -112,7 +106,6 @@ void tc_clksrc_resume(struct clocksource *cs)
}
static struct clocksource clksrc = {
- .name = "tcb_clksrc",
.rating = 200,
.read = tc_get_cycles,
.mask = CLOCKSOURCE_MASK(32),
@@ -214,7 +207,6 @@ static int tc_next_event(unsigned long delta, struct clock_event_device *d)
static struct tc_clkevt_device clkevt = {
.clkevt = {
- .name = "tc_clkevt",
.features = CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_ONESHOT,
/* Should be lower than at91rm9200's system timer */
@@ -330,39 +322,73 @@ static void __init tcb_setup_single_chan(struct atmel_tc *tc, int mck_divisor_id
writel(ATMEL_TC_SYNC, tcaddr + ATMEL_TC_BCR);
}
-static int __init tcb_clksrc_init(void)
-{
- static char bootinfo[] __initdata
- = KERN_DEBUG "%s: tc%d at %d.%03d MHz\n";
+static const u8 atmel_tcb_divisors[5] = { 2, 8, 32, 128, 0, };
+
+static const struct of_device_id atmel_tcb_of_match[] = {
+ { .compatible = "atmel,at91rm9200-tcb", .data = (void *)16, },
+ { .compatible = "atmel,at91sam9x5-tcb", .data = (void *)32, },
+ { /* sentinel */ }
+};
- struct platform_device *pdev;
- struct atmel_tc *tc;
+static int __init tcb_clksrc_init(struct device_node *node)
+{
+ struct atmel_tc tc;
struct clk *t0_clk;
+ const struct of_device_id *match;
u32 rate, divided_rate = 0;
int best_divisor_idx = -1;
int clk32k_divisor_idx = -1;
+ int bits;
int i;
int ret;
- tc = atmel_tc_alloc(CONFIG_ATMEL_TCB_CLKSRC_BLOCK);
- if (!tc) {
- pr_debug("can't alloc TC for clocksource\n");
- return -ENODEV;
+ /* Protect against multiple calls */
+ if (tcaddr)
+ return 0;
+
+ tc.regs = of_iomap(node->parent, 0);
+ if (!tc.regs)
+ return -ENXIO;
+
+ t0_clk = of_clk_get_by_name(node->parent, "t0_clk");
+ if (IS_ERR(t0_clk))
+ return PTR_ERR(t0_clk);
+
+ tc.slow_clk = of_clk_get_by_name(node->parent, "slow_clk");
+ if (IS_ERR(tc.slow_clk))
+ return PTR_ERR(tc.slow_clk);
+
+ tc.clk[0] = t0_clk;
+ tc.clk[1] = of_clk_get_by_name(node->parent, "t1_clk");
+ if (IS_ERR(tc.clk[1]))
+ tc.clk[1] = t0_clk;
+ tc.clk[2] = of_clk_get_by_name(node->parent, "t2_clk");
+ if (IS_ERR(tc.clk[2]))
+ tc.clk[2] = t0_clk;
+
+ tc.irq[2] = of_irq_get(node->parent, 2);
+ if (tc.irq[2] <= 0) {
+ tc.irq[2] = of_irq_get(node->parent, 0);
+ if (tc.irq[2] <= 0)
+ return -EINVAL;
}
- tcaddr = tc->regs;
- pdev = tc->pdev;
- t0_clk = tc->clk[0];
+ match = of_match_node(atmel_tcb_of_match, node->parent);
+ bits = (uintptr_t)match->data;
+
+ for (i = 0; i < ARRAY_SIZE(tc.irq); i++)
+ writel(ATMEL_TC_ALL_IRQ, tc.regs + ATMEL_TC_REG(i, IDR));
+
ret = clk_prepare_enable(t0_clk);
if (ret) {
pr_debug("can't enable T0 clk\n");
- goto err_free_tc;
+ return ret;
}
/* How fast will we be counting? Pick something over 5 MHz. */
rate = (u32) clk_get_rate(t0_clk);
- for (i = 0; i < 5; i++) {
- unsigned divisor = atmel_tc_divisors[i];
+ for (i = 0; i < ARRAY_SIZE(atmel_tcb_divisors); i++) {
+ unsigned divisor = atmel_tcb_divisors[i];
unsigned tmp;
/* remember 32 KiHz clock for later */
@@ -381,27 +407,29 @@ static int __init tcb_clksrc_init(void)
best_divisor_idx = i;
}
-
- printk(bootinfo, clksrc.name, CONFIG_ATMEL_TCB_CLKSRC_BLOCK,
- divided_rate / 1000000,
+ clksrc.name = kbasename(node->parent->full_name);
+ clkevt.clkevt.name = kbasename(node->parent->full_name);
+ pr_debug("%s at %d.%03d MHz\n", clksrc.name, divided_rate / 1000000,
((divided_rate % 1000000) + 500) / 1000);
- if (tc->tcb_config && tc->tcb_config->counter_width == 32) {
+ tcaddr = tc.regs;
+
+ if (bits == 32) {
/* use apropriate function to read 32 bit counter */
clksrc.read = tc_get_cycles32;
/* setup ony channel 0 */
- tcb_setup_single_chan(tc, best_divisor_idx);
+ tcb_setup_single_chan(&tc, best_divisor_idx);
} else {
- /* tclib will give us three clocks no matter what the
+ /* we have three clocks no matter what the
* underlying platform supports.
*/
- ret = clk_prepare_enable(tc->clk[1]);
+ ret = clk_prepare_enable(tc.clk[1]);
if (ret) {
pr_debug("can't enable T1 clk\n");
goto err_disable_t0;
}
/* setup both channel 0 & 1 */
- tcb_setup_dual_chan(tc, best_divisor_idx);
+ tcb_setup_dual_chan(&tc, best_divisor_idx);
}
/* and away we go! */
@@ -410,7 +438,7 @@ static int __init tcb_clksrc_init(void)
goto err_disable_t1;
/* channel 2: periodic and oneshot timer support */
- ret = setup_clkevents(tc, clk32k_divisor_idx);
+ ret = setup_clkevents(&tc, clk32k_divisor_idx);
if (ret)
goto err_unregister_clksrc;
@@ -420,14 +448,14 @@ static int __init tcb_clksrc_init(void)
clocksource_unregister(&clksrc);
err_disable_t1:
- if (!tc->tcb_config || tc->tcb_config->counter_width != 32)
- clk_disable_unprepare(tc->clk[1]);
+ if (bits != 32)
+ clk_disable_unprepare(tc.clk[1]);
err_disable_t0:
clk_disable_unprepare(t0_clk);
-err_free_tc:
- atmel_tc_free(tc);
+ tcaddr = NULL;
+
return ret;
}
-arch_initcall(tcb_clksrc_init);
+TIMER_OF_DECLARE(atmel_tcb_clksrc, "atmel,tcb-timer", tcb_clksrc_init);
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 42ab8ec92a04..268a01d3d6f3 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -61,7 +61,8 @@ config ATMEL_TCLIB
config ATMEL_TCB_CLKSRC
bool "TC Block Clocksource"
- depends on ATMEL_TCLIB
+ depends on ARCH_AT91
+ select TIMER_OF if OF
default y
help
Select this to get a high precision clocksource based on a
@@ -72,17 +73,6 @@ config ATMEL_TCB_CLKSRC
may be used as a clock event device supporting oneshot mode
(delays of up to two seconds) based on the 32 KiHz clock.
-config ATMEL_TCB_CLKSRC_BLOCK
- int
- depends on ATMEL_TCB_CLKSRC
- default 0
- range 0 1
- help
- Some chips provide more than one TC block, so you have the
- choice of which one to use for the clock framework. The other
- TC can be used for other purposes, such as PWM generation and
- interval timing.
-
config DUMMY_IRQ
tristate "Dummy IRQ handler"
default n
--
2.20.1
For the sake of consistency, let's rename the file to a name similar
to other file names in this directory.
Signed-off-by: Alexandre Belloni <[email protected]>
---
drivers/clocksource/Makefile | 2 +-
drivers/clocksource/{tcb_clksrc.c => timer-atmel-tcb.c} | 0
2 files changed, 1 insertion(+), 1 deletion(-)
rename drivers/clocksource/{tcb_clksrc.c => timer-atmel-tcb.c} (100%)
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index be6e0fbc7489..923b9b60c909 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -3,7 +3,7 @@ obj-$(CONFIG_TIMER_OF) += timer-of.o
obj-$(CONFIG_TIMER_PROBE) += timer-probe.o
obj-$(CONFIG_ATMEL_PIT) += timer-atmel-pit.o
obj-$(CONFIG_ATMEL_ST) += timer-atmel-st.o
-obj-$(CONFIG_ATMEL_TCB_CLKSRC) += tcb_clksrc.o
+obj-$(CONFIG_ATMEL_TCB_CLKSRC) += timer-atmel-tcb.o
obj-$(CONFIG_X86_PM_TIMER) += acpi_pm.o
obj-$(CONFIG_SCx200HR_TIMER) += scx200_hrt.o
obj-$(CONFIG_CS5535_CLOCK_EVENT_SRC) += timer-cs5535.o
diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/timer-atmel-tcb.c
similarity index 100%
rename from drivers/clocksource/tcb_clksrc.c
rename to drivers/clocksource/timer-atmel-tcb.c
--
2.20.1
From: kbuild test robot <[email protected]>
Statisticize tc_clksrc_suspend and tc_clksrc_resume.
Signed-off-by: kbuild test robot <[email protected]>
Signed-off-by: Alexandre Belloni <[email protected]>
---
drivers/clocksource/timer-atmel-tcb.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/clocksource/timer-atmel-tcb.c b/drivers/clocksource/timer-atmel-tcb.c
index 9de8c10ab546..6ed31f9def7e 100644
--- a/drivers/clocksource/timer-atmel-tcb.c
+++ b/drivers/clocksource/timer-atmel-tcb.c
@@ -66,7 +66,7 @@ static u64 tc_get_cycles32(struct clocksource *cs)
return readl_relaxed(tcaddr + ATMEL_TC_REG(0, CV));
}
-void tc_clksrc_suspend(struct clocksource *cs)
+static void tc_clksrc_suspend(struct clocksource *cs)
{
int i;
@@ -81,7 +81,7 @@ void tc_clksrc_suspend(struct clocksource *cs)
bmr_cache = readl(tcaddr + ATMEL_TC_BMR);
}
-void tc_clksrc_resume(struct clocksource *cs)
+static void tc_clksrc_resume(struct clocksource *cs)
{
int i;
--
2.20.1
Allow building the PIT driver when COMPILE_TEST is enabled. Also remove its
default value so it can be disabled.
Signed-off-by: Alexandre Belloni <[email protected]>
---
drivers/clocksource/Kconfig | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index e38ef4906e30..c73736f87600 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -399,8 +399,11 @@ config ARMV7M_SYSTICK
This options enables support for the ARMv7M system timer unit
config ATMEL_PIT
+ bool "Atmel PIT support" if COMPILE_TEST
+ depends on HAS_IOMEM
select TIMER_OF if OF
- def_bool SOC_AT91SAM9 || SOC_SAMA5
+ help
+ Support for the Periodic Interval Timer found on Atmel SoCs.
config ATMEL_ST
bool "Atmel ST timer support" if COMPILE_TEST
--
2.20.1
Move the ATMEL_TCB_CLKSRC option to drivers/clocksource and make it silent
if COMPILE_TEST is not selected.
Signed-off-by: Alexandre Belloni <[email protected]>
---
drivers/clocksource/Kconfig | 7 +++++++
drivers/misc/Kconfig | 14 --------------
2 files changed, 7 insertions(+), 14 deletions(-)
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 171502a356aa..e38ef4906e30 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -410,6 +410,13 @@ config ATMEL_ST
help
Support for the Atmel ST timer.
+config ATMEL_TCB_CLKSRC
+ bool "Atmel TC Block timer driver" if COMPILE_TEST
+ depends on HAS_IOMEM
+ select TIMER_OF if OF
+ help
+ Support for Timer Counter Blocks on Atmel SoCs.
+
config CLKSRC_EXYNOS_MCT
bool "Exynos multi core timer driver" if COMPILE_TEST
depends on ARM || ARM64
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 268a01d3d6f3..c84033909395 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -59,20 +59,6 @@ config ATMEL_TCLIB
blocks found on many Atmel processors. This facilitates using
these blocks by different drivers despite processor differences.
-config ATMEL_TCB_CLKSRC
- bool "TC Block Clocksource"
- depends on ARCH_AT91
- select TIMER_OF if OF
- default y
- help
- Select this to get a high precision clocksource based on a
- TC block with a 5+ MHz base clock rate. Two timer channels
- are combined to make a single 32-bit timer.
-
- When GENERIC_CLOCKEVENTS is defined, the third timer channel
- may be used as a clock event device supporting oneshot mode
- (delays of up to two seconds) based on the 32 KiHz clock.
-
config DUMMY_IRQ
tristate "Dummy IRQ handler"
default n
--
2.20.1
Now that the driver is registered early enough, use the TCB as the
sched_clock which is much more accurate than the jiffies implementation.
Signed-off-by: Alexandre Belloni <[email protected]>
---
drivers/clocksource/tcb_clksrc.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index bf68504da94a..9de8c10ab546 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -11,6 +11,7 @@
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
+#include <linux/sched_clock.h>
#include <linux/syscore_ops.h>
#include <soc/at91/atmel_tcb.h>
@@ -114,6 +115,16 @@ static struct clocksource clksrc = {
.resume = tc_clksrc_resume,
};
+static u64 notrace tc_sched_clock_read(void)
+{
+ return tc_get_cycles(&clksrc);
+}
+
+static u64 notrace tc_sched_clock_read32(void)
+{
+ return tc_get_cycles32(&clksrc);
+}
+
#ifdef CONFIG_GENERIC_CLOCKEVENTS
struct tc_clkevt_device {
@@ -335,6 +346,7 @@ static int __init tcb_clksrc_init(struct device_node *node)
struct atmel_tc tc;
struct clk *t0_clk;
const struct of_device_id *match;
+ u64 (*tc_sched_clock)(void);
u32 rate, divided_rate = 0;
int best_divisor_idx = -1;
int clk32k_divisor_idx = -1;
@@ -419,6 +431,7 @@ static int __init tcb_clksrc_init(struct device_node *node)
clksrc.read = tc_get_cycles32;
/* setup ony channel 0 */
tcb_setup_single_chan(&tc, best_divisor_idx);
+ tc_sched_clock = tc_sched_clock_read32;
} else {
/* we have three clocks no matter what the
* underlying platform supports.
@@ -430,6 +443,7 @@ static int __init tcb_clksrc_init(struct device_node *node)
}
/* setup both channel 0 & 1 */
tcb_setup_dual_chan(&tc, best_divisor_idx);
+ tc_sched_clock = tc_sched_clock_read;
}
/* and away we go! */
@@ -442,6 +456,8 @@ static int __init tcb_clksrc_init(struct device_node *node)
if (ret)
goto err_unregister_clksrc;
+ sched_clock_register(tc_sched_clock, 32, divided_rate);
+
return 0;
err_unregister_clksrc:
--
2.20.1
The TCBs that have children are using the proper DT bindings and don't need
to be handled by tclib.
Cc: Arnd Bergmann <[email protected]>
Signed-off-by: Alexandre Belloni <[email protected]>
---
drivers/misc/atmel_tclib.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/misc/atmel_tclib.c b/drivers/misc/atmel_tclib.c
index 194f774ab3a1..c1f5aba1c6f2 100644
--- a/drivers/misc/atmel_tclib.c
+++ b/drivers/misc/atmel_tclib.c
@@ -111,6 +111,9 @@ static int __init tc_probe(struct platform_device *pdev)
struct resource *r;
unsigned int i;
+ if (of_get_child_count(pdev->dev.of_node))
+ return 0;
+
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return -EINVAL;
--
2.20.1
Move linux/atmel_tc.h to the SoC specific folder include/soc/at91.
Signed-off-by: Alexandre Belloni <[email protected]>
Acked-by: Thierry Reding <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
---
drivers/clocksource/tcb_clksrc.c | 2 +-
drivers/misc/atmel_tclib.c | 2 +-
drivers/pwm/pwm-atmel-tcb.c | 2 +-
include/{linux/atmel_tc.h => soc/at91/atmel_tcb.h} | 4 ++--
4 files changed, 5 insertions(+), 5 deletions(-)
rename include/{linux/atmel_tc.h => soc/at91/atmel_tcb.h} (99%)
diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 43f4d5c4d6fa..138a12090149 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -11,7 +11,7 @@
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/syscore_ops.h>
-#include <linux/atmel_tc.h>
+#include <soc/at91/atmel_tcb.h>
/*
diff --git a/drivers/misc/atmel_tclib.c b/drivers/misc/atmel_tclib.c
index ac24a4bd63f7..194f774ab3a1 100644
--- a/drivers/misc/atmel_tclib.c
+++ b/drivers/misc/atmel_tclib.c
@@ -1,4 +1,3 @@
-#include <linux/atmel_tc.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/init.h>
@@ -10,6 +9,7 @@
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/of.h>
+#include <soc/at91/atmel_tcb.h>
/*
* This is a thin library to solve the problem of how to portably allocate
diff --git a/drivers/pwm/pwm-atmel-tcb.c b/drivers/pwm/pwm-atmel-tcb.c
index 0d0f8376bc35..7da1fdb4d269 100644
--- a/drivers/pwm/pwm-atmel-tcb.c
+++ b/drivers/pwm/pwm-atmel-tcb.c
@@ -17,10 +17,10 @@
#include <linux/ioport.h>
#include <linux/io.h>
#include <linux/platform_device.h>
-#include <linux/atmel_tc.h>
#include <linux/pwm.h>
#include <linux/of_device.h>
#include <linux/slab.h>
+#include <soc/at91/atmel_tcb.h>
#define NPWM 6
diff --git a/include/linux/atmel_tc.h b/include/soc/at91/atmel_tcb.h
similarity index 99%
rename from include/linux/atmel_tc.h
rename to include/soc/at91/atmel_tcb.h
index 468fdfa643f0..c3c7200ce151 100644
--- a/include/linux/atmel_tc.h
+++ b/include/soc/at91/atmel_tcb.h
@@ -7,8 +7,8 @@
* (at your option) any later version.
*/
-#ifndef ATMEL_TC_H
-#define ATMEL_TC_H
+#ifndef __SOC_ATMEL_TCB_H
+#define __SOC_ATMEL_TCB_H
#include <linux/compiler.h>
#include <linux/list.h>
--
2.20.1
Allow selecting and unselecting the PIT clocksource driver so it doesn't
have to be compiled when unused.
Signed-off-by: Alexandre Belloni <[email protected]>
---
arch/arm/mach-at91/Kconfig | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
index 903f23c309df..da1d97a06c53 100644
--- a/arch/arm/mach-at91/Kconfig
+++ b/arch/arm/mach-at91/Kconfig
@@ -107,6 +107,29 @@ config SOC_AT91SAM9
AT91SAM9X35
AT91SAM9XE
+comment "Clocksource driver selection"
+
+config ATMEL_CLOCKSOURCE_PIT
+ bool "Periodic Interval Timer (PIT) support"
+ depends on SOC_AT91SAM9 || SOC_SAMA5
+ default SOC_AT91SAM9 || SOC_SAMA5
+ select ATMEL_PIT
+ help
+ Select this to get a clocksource based on the Atmel Periodic Interval
+ Timer. It has a relatively low resolution and the TC Block clocksource
+ should be preferred.
+
+config ATMEL_CLOCKSOURCE_TCB
+ bool "Timer Counter Blocks (TCB) support"
+ default SOC_AT91RM9200 || SOC_AT91SAM9 || SOC_SAMA5
+ select ATMEL_TCB_CLKSRC
+ help
+ Select this to get a high precision clocksource based on a
+ TC block with a 5+ MHz base clock rate.
+ On platforms with 16-bit counters, two timer channels are combined
+ to make a single 32-bit timer.
+ It can also be used as a clock event device supporting oneshot mode.
+
config HAVE_AT91_UTMI
bool
--
2.20.1
Arnd can you ack this patch? I would like to take the series via my tree.
On 15/04/2019 17:08, Alexandre Belloni wrote:
> Move the ATMEL_TCB_CLKSRC option to drivers/clocksource and make it silent
> if COMPILE_TEST is not selected.
>
> Signed-off-by: Alexandre Belloni <[email protected]>
> ---
> drivers/clocksource/Kconfig | 7 +++++++
> drivers/misc/Kconfig | 14 --------------
> 2 files changed, 7 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
> index 171502a356aa..e38ef4906e30 100644
> --- a/drivers/clocksource/Kconfig
> +++ b/drivers/clocksource/Kconfig
> @@ -410,6 +410,13 @@ config ATMEL_ST
> help
> Support for the Atmel ST timer.
>
> +config ATMEL_TCB_CLKSRC
> + bool "Atmel TC Block timer driver" if COMPILE_TEST
> + depends on HAS_IOMEM
> + select TIMER_OF if OF
> + help
> + Support for Timer Counter Blocks on Atmel SoCs.
> +
> config CLKSRC_EXYNOS_MCT
> bool "Exynos multi core timer driver" if COMPILE_TEST
> depends on ARM || ARM64
> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> index 268a01d3d6f3..c84033909395 100644
> --- a/drivers/misc/Kconfig
> +++ b/drivers/misc/Kconfig
> @@ -59,20 +59,6 @@ config ATMEL_TCLIB
> blocks found on many Atmel processors. This facilitates using
> these blocks by different drivers despite processor differences.
>
> -config ATMEL_TCB_CLKSRC
> - bool "TC Block Clocksource"
> - depends on ARCH_AT91
> - select TIMER_OF if OF
> - default y
> - help
> - Select this to get a high precision clocksource based on a
> - TC block with a 5+ MHz base clock rate. Two timer channels
> - are combined to make a single 32-bit timer.
> -
> - When GENERIC_CLOCKEVENTS is defined, the third timer channel
> - may be used as a clock event device supporting oneshot mode
> - (delays of up to two seconds) based on the 32 KiHz clock.
> -
> config DUMMY_IRQ
> tristate "Dummy IRQ handler"
> default n
>
--
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On Mon, Apr 15, 2019 at 05:08:56PM +0200, Alexandre Belloni wrote:
> The TCBs that have children are using the proper DT bindings and don't need
> to be handled by tclib.
>
> Cc: Arnd Bergmann <[email protected]>
> Signed-off-by: Alexandre Belloni <[email protected]>
> ---
> drivers/misc/atmel_tclib.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/misc/atmel_tclib.c b/drivers/misc/atmel_tclib.c
> index 194f774ab3a1..c1f5aba1c6f2 100644
> --- a/drivers/misc/atmel_tclib.c
> +++ b/drivers/misc/atmel_tclib.c
> @@ -111,6 +111,9 @@ static int __init tc_probe(struct platform_device *pdev)
> struct resource *r;
> unsigned int i;
>
> + if (of_get_child_count(pdev->dev.of_node))
> + return 0;
> +
> irq = platform_get_irq(pdev, 0);
> if (irq < 0)
> return -EINVAL;
This lead to a panic during shutdown, as tc_shutdown is called on the
device that has not been initialized and it has not been designed for
this.
--
Romain Izard
On 17/04/2019 13:50:25+0200, Romain Izard wrote:
> On Mon, Apr 15, 2019 at 05:08:56PM +0200, Alexandre Belloni wrote:
> > The TCBs that have children are using the proper DT bindings and don't need
> > to be handled by tclib.
> >
> > Cc: Arnd Bergmann <[email protected]>
> > Signed-off-by: Alexandre Belloni <[email protected]>
> > ---
> > drivers/misc/atmel_tclib.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/misc/atmel_tclib.c b/drivers/misc/atmel_tclib.c
> > index 194f774ab3a1..c1f5aba1c6f2 100644
> > --- a/drivers/misc/atmel_tclib.c
> > +++ b/drivers/misc/atmel_tclib.c
> > @@ -111,6 +111,9 @@ static int __init tc_probe(struct platform_device *pdev)
> > struct resource *r;
> > unsigned int i;
> >
> > + if (of_get_child_count(pdev->dev.of_node))
> > + return 0;
> > +
> > irq = platform_get_irq(pdev, 0);
> > if (irq < 0)
> > return -EINVAL;
>
> This lead to a panic during shutdown, as tc_shutdown is called on the
> device that has not been initialized and it has not been designed for
> this.
>
Yes, I saw that yesterday, the solution is to return -EBUSY instead of
0. That's what I had in my original series and I changed it before
submitting to avoid the error message at boot but this was not a good
idea.
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com