2022-04-21 00:41:41

by Arnd Bergmann

[permalink] [raw]
Subject: [PATCH 17/41] ARM: omap1: move 32k counter from plat-omap to mach-omap1

From: Arnd Bergmann <[email protected]>

omap2 stopped using this code with commit 8d39ff3d1696 ("ARM: OMAP2+:
Remove unused legacy code for timer"), so just move it to mach-omap1 now,
along with the other half of that driver.

Signed-off-by: Arnd Bergmann <[email protected]>
---
arch/arm/mach-omap1/Kconfig | 16 +++
arch/arm/mach-omap1/timer32k.c | 96 ++++++++++++++-
arch/arm/plat-omap/Kconfig | 17 ---
arch/arm/plat-omap/Makefile | 2 +-
arch/arm/plat-omap/counter_32k.c | 114 ------------------
arch/arm/plat-omap/include/plat/counter-32k.h | 1 -
6 files changed, 110 insertions(+), 136 deletions(-)
delete mode 100644 arch/arm/plat-omap/counter_32k.c
delete mode 100644 arch/arm/plat-omap/include/plat/counter-32k.h

diff --git a/arch/arm/mach-omap1/Kconfig b/arch/arm/mach-omap1/Kconfig
index 208c700c2455..04155b5ce978 100644
--- a/arch/arm/mach-omap1/Kconfig
+++ b/arch/arm/mach-omap1/Kconfig
@@ -53,6 +53,22 @@ config OMAP_MUX_WARNINGS
to change the pin multiplexing setup. When there are no warnings
printed, it's safe to deselect OMAP_MUX for your product.

+config OMAP_32K_TIMER
+ bool "Use 32KHz timer"
+ depends on ARCH_OMAP16XX
+ default ARCH_OMAP16XX
+ help
+ Select this option if you want to enable the OMAP 32KHz timer.
+ This timer saves power compared to the OMAP_MPU_TIMER, and has
+ support for no tick during idle. The 32KHz timer provides less
+ intra-tick resolution than OMAP_MPU_TIMER. The 32KHz timer is
+ currently only available for OMAP16XX, 24XX, 34XX, OMAP4/5 and DRA7XX.
+
+ On OMAP2PLUS this value is only used for CONFIG_HZ and
+ CLOCK_TICK_RATE compile time calculation.
+ The actual timer selection is done in the board file
+ through the (DT_)MACHINE_START structure.
+
comment "OMAP Board Type"

config MACH_OMAP_INNOVATOR
diff --git a/arch/arm/mach-omap1/timer32k.c b/arch/arm/mach-omap1/timer32k.c
index 780fdf03c3ce..11958ccd894d 100644
--- a/arch/arm/mach-omap1/timer32k.c
+++ b/arch/arm/mach-omap1/timer32k.c
@@ -45,15 +45,13 @@
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/io.h>
+#include <linux/sched_clock.h>

#include <asm/irq.h>
#include <asm/mach/irq.h>
#include <asm/mach/time.h>

-#include <plat/counter-32k.h>
-
#include <mach/hardware.h>
-
#include "common.h"

/*
@@ -159,6 +157,98 @@ static __init void omap_init_32k_timer(void)
OMAP_32K_TICKS_PER_SEC, 1, 0xfffffffe);
}

+/* OMAP2_32KSYNCNT_CR_OFF: offset of 32ksync counter register */
+#define OMAP2_32KSYNCNT_REV_OFF 0x0
+#define OMAP2_32KSYNCNT_REV_SCHEME (0x3 << 30)
+#define OMAP2_32KSYNCNT_CR_OFF_LOW 0x10
+#define OMAP2_32KSYNCNT_CR_OFF_HIGH 0x30
+
+/*
+ * 32KHz clocksource ... always available, on pretty most chips except
+ * OMAP 730 and 1510. Other timers could be used as clocksources, with
+ * higher resolution in free-running counter modes (e.g. 12 MHz xtal),
+ * but systems won't necessarily want to spend resources that way.
+ */
+static void __iomem *sync32k_cnt_reg;
+
+static u64 notrace omap_32k_read_sched_clock(void)
+{
+ return sync32k_cnt_reg ? readl_relaxed(sync32k_cnt_reg) : 0;
+}
+
+/**
+ * omap_read_persistent_clock64 - Return time from a persistent clock.
+ *
+ * Reads the time from a source which isn't disabled during PM, the
+ * 32k sync timer. Convert the cycles elapsed since last read into
+ * nsecs and adds to a monotonically increasing timespec64.
+ */
+static struct timespec64 persistent_ts;
+static cycles_t cycles;
+static unsigned int persistent_mult, persistent_shift;
+
+static void omap_read_persistent_clock64(struct timespec64 *ts)
+{
+ unsigned long long nsecs;
+ cycles_t last_cycles;
+
+ last_cycles = cycles;
+ cycles = sync32k_cnt_reg ? readl_relaxed(sync32k_cnt_reg) : 0;
+
+ nsecs = clocksource_cyc2ns(cycles - last_cycles,
+ persistent_mult, persistent_shift);
+
+ timespec64_add_ns(&persistent_ts, nsecs);
+
+ *ts = persistent_ts;
+}
+
+/**
+ * omap_init_clocksource_32k - setup and register counter 32k as a
+ * kernel clocksource
+ * @pbase: base addr of counter_32k module
+ * @size: size of counter_32k to map
+ *
+ * Returns 0 upon success or negative error code upon failure.
+ *
+ */
+int __init omap_init_clocksource_32k(void __iomem *vbase)
+{
+ int ret;
+
+ /*
+ * 32k sync Counter IP register offsets vary between the
+ * highlander version and the legacy ones.
+ * The 'SCHEME' bits(30-31) of the revision register is used
+ * to identify the version.
+ */
+ if (readl_relaxed(vbase + OMAP2_32KSYNCNT_REV_OFF) &
+ OMAP2_32KSYNCNT_REV_SCHEME)
+ sync32k_cnt_reg = vbase + OMAP2_32KSYNCNT_CR_OFF_HIGH;
+ else
+ sync32k_cnt_reg = vbase + OMAP2_32KSYNCNT_CR_OFF_LOW;
+
+ /*
+ * 120000 rough estimate from the calculations in
+ * __clocksource_update_freq_scale.
+ */
+ clocks_calc_mult_shift(&persistent_mult, &persistent_shift,
+ 32768, NSEC_PER_SEC, 120000);
+
+ ret = clocksource_mmio_init(sync32k_cnt_reg, "32k_counter", 32768,
+ 250, 32, clocksource_mmio_readl_up);
+ if (ret) {
+ pr_err("32k_counter: can't register clocksource\n");
+ return ret;
+ }
+
+ sched_clock_register(omap_32k_read_sched_clock, 32, 32768);
+ register_persistent_clock(omap_read_persistent_clock64);
+ pr_info("OMAP clocksource: 32k_counter at 32768 Hz\n");
+
+ return 0;
+}
+
/*
* ---------------------------------------------------------------------------
* Timer initialization
diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
index 272670ef1e92..dfa19d5030e3 100644
--- a/arch/arm/plat-omap/Kconfig
+++ b/arch/arm/plat-omap/Kconfig
@@ -72,23 +72,6 @@ config OMAP_MPU_TIMER
timer provides more intra-tick resolution than the 32KHz timer,
but consumes more power.

-config OMAP_32K_TIMER
- bool "Use 32KHz timer"
- depends on ARCH_OMAP16XX || ARCH_OMAP2PLUS
- default y if (ARCH_OMAP16XX || ARCH_OMAP2PLUS)
- help
- Select this option if you want to enable the OMAP 32KHz timer.
- This timer saves power compared to the OMAP_MPU_TIMER, and has
- support for no tick during idle. The 32KHz timer provides less
- intra-tick resolution than OMAP_MPU_TIMER. The 32KHz timer is
- currently only available for OMAP16XX, 24XX, 34XX, OMAP4/5 and DRA7XX.
-
- On OMAP2PLUS this value is only used for CONFIG_HZ and
- CLOCK_TICK_RATE compile time calculation.
- The actual timer selection is done in the board file
- through the (DT_)MACHINE_START structure.
-
-
config OMAP3_L2_AUX_SECURE_SAVE_RESTORE
bool "OMAP3 HS/EMU save and restore for L2 AUX control register"
depends on ARCH_OMAP3 && PM
diff --git a/arch/arm/plat-omap/Makefile b/arch/arm/plat-omap/Makefile
index 371f2ed00eda..98a7b607873a 100644
--- a/arch/arm/plat-omap/Makefile
+++ b/arch/arm/plat-omap/Makefile
@@ -6,7 +6,7 @@
ccflags-$(CONFIG_ARCH_MULTIPLATFORM) := -I$(srctree)/arch/arm/plat-omap/include

# Common support
-obj-y := sram.o dma.o counter_32k.o
+obj-y := sram.o dma.o

# omap_device support (OMAP2+ only at the moment)

diff --git a/arch/arm/plat-omap/counter_32k.c b/arch/arm/plat-omap/counter_32k.c
deleted file mode 100644
index 7a729ade2105..000000000000
--- a/arch/arm/plat-omap/counter_32k.c
+++ /dev/null
@@ -1,114 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * OMAP 32ksynctimer/counter_32k-related code
- *
- * Copyright (C) 2009 Texas Instruments
- * Copyright (C) 2010 Nokia Corporation
- * Tony Lindgren <[email protected]>
- * Added OMAP4 support - Santosh Shilimkar <[email protected]>
- *
- * NOTE: This timer is not the same timer as the old OMAP1 MPU timer.
- */
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/clk.h>
-#include <linux/err.h>
-#include <linux/io.h>
-#include <linux/clocksource.h>
-#include <linux/sched_clock.h>
-
-#include <asm/mach/time.h>
-
-#include <plat/counter-32k.h>
-
-/* OMAP2_32KSYNCNT_CR_OFF: offset of 32ksync counter register */
-#define OMAP2_32KSYNCNT_REV_OFF 0x0
-#define OMAP2_32KSYNCNT_REV_SCHEME (0x3 << 30)
-#define OMAP2_32KSYNCNT_CR_OFF_LOW 0x10
-#define OMAP2_32KSYNCNT_CR_OFF_HIGH 0x30
-
-/*
- * 32KHz clocksource ... always available, on pretty most chips except
- * OMAP 730 and 1510. Other timers could be used as clocksources, with
- * higher resolution in free-running counter modes (e.g. 12 MHz xtal),
- * but systems won't necessarily want to spend resources that way.
- */
-static void __iomem *sync32k_cnt_reg;
-
-static u64 notrace omap_32k_read_sched_clock(void)
-{
- return sync32k_cnt_reg ? readl_relaxed(sync32k_cnt_reg) : 0;
-}
-
-/**
- * omap_read_persistent_clock64 - Return time from a persistent clock.
- *
- * Reads the time from a source which isn't disabled during PM, the
- * 32k sync timer. Convert the cycles elapsed since last read into
- * nsecs and adds to a monotonically increasing timespec64.
- */
-static struct timespec64 persistent_ts;
-static cycles_t cycles;
-static unsigned int persistent_mult, persistent_shift;
-
-static void omap_read_persistent_clock64(struct timespec64 *ts)
-{
- unsigned long long nsecs;
- cycles_t last_cycles;
-
- last_cycles = cycles;
- cycles = sync32k_cnt_reg ? readl_relaxed(sync32k_cnt_reg) : 0;
-
- nsecs = clocksource_cyc2ns(cycles - last_cycles,
- persistent_mult, persistent_shift);
-
- timespec64_add_ns(&persistent_ts, nsecs);
-
- *ts = persistent_ts;
-}
-
-/**
- * omap_init_clocksource_32k - setup and register counter 32k as a
- * kernel clocksource
- * @pbase: base addr of counter_32k module
- * @size: size of counter_32k to map
- *
- * Returns 0 upon success or negative error code upon failure.
- *
- */
-int __init omap_init_clocksource_32k(void __iomem *vbase)
-{
- int ret;
-
- /*
- * 32k sync Counter IP register offsets vary between the
- * highlander version and the legacy ones.
- * The 'SCHEME' bits(30-31) of the revision register is used
- * to identify the version.
- */
- if (readl_relaxed(vbase + OMAP2_32KSYNCNT_REV_OFF) &
- OMAP2_32KSYNCNT_REV_SCHEME)
- sync32k_cnt_reg = vbase + OMAP2_32KSYNCNT_CR_OFF_HIGH;
- else
- sync32k_cnt_reg = vbase + OMAP2_32KSYNCNT_CR_OFF_LOW;
-
- /*
- * 120000 rough estimate from the calculations in
- * __clocksource_update_freq_scale.
- */
- clocks_calc_mult_shift(&persistent_mult, &persistent_shift,
- 32768, NSEC_PER_SEC, 120000);
-
- ret = clocksource_mmio_init(sync32k_cnt_reg, "32k_counter", 32768,
- 250, 32, clocksource_mmio_readl_up);
- if (ret) {
- pr_err("32k_counter: can't register clocksource\n");
- return ret;
- }
-
- sched_clock_register(omap_32k_read_sched_clock, 32, 32768);
- register_persistent_clock(omap_read_persistent_clock64);
- pr_info("OMAP clocksource: 32k_counter at 32768 Hz\n");
-
- return 0;
-}
diff --git a/arch/arm/plat-omap/include/plat/counter-32k.h b/arch/arm/plat-omap/include/plat/counter-32k.h
deleted file mode 100644
index da000d482ff2..000000000000
--- a/arch/arm/plat-omap/include/plat/counter-32k.h
+++ /dev/null
@@ -1 +0,0 @@
-int omap_init_clocksource_32k(void __iomem *vbase);
--
2.29.2


2022-04-22 18:03:03

by Tony Lindgren

[permalink] [raw]
Subject: Re: [PATCH 17/41] ARM: omap1: move 32k counter from plat-omap to mach-omap1

* Arnd Bergmann <[email protected]> [220419 13:36]:
> From: Arnd Bergmann <[email protected]>
>
> omap2 stopped using this code with commit 8d39ff3d1696 ("ARM: OMAP2+:
> Remove unused legacy code for timer"), so just move it to mach-omap1 now,
> along with the other half of that driver.

BTW, if omap1 gains devicetree support, chances are that the
drivers/clocksource/timer-ti-32k.c will be usable with minor
modifications.

Regards,

Tony