[PATCH v3 1/3] MIPS: Loongson32: Remove deprecated PWM timer clocksource

From: Keguang Zhang
Date: Thu Mar 30 2023 - 07:05:51 EST


The Loongson1 PWM timer will be moved to clocksource framework.
Then, the old driver is no longer needed.
Remove the deprecated code and update the Kconfig.

Signed-off-by: Keguang Zhang <keguang.zhang@xxxxxxxxx>
---
V2 -> V3: Remove the reference to regs-pwm.h
V1 -> V2: Delete the obsolete header file regs-pwm.h
---
.../include/asm/mach-loongson32/loongson1.h | 1 -
.../include/asm/mach-loongson32/regs-pwm.h | 25 ---
arch/mips/loongson32/Kconfig | 37 ---
arch/mips/loongson32/common/time.c | 210 ------------------
4 files changed, 273 deletions(-)
delete mode 100644 arch/mips/include/asm/mach-loongson32/regs-pwm.h

diff --git a/arch/mips/include/asm/mach-loongson32/loongson1.h b/arch/mips/include/asm/mach-loongson32/loongson1.h
index eb3ddbec1752..d8f9dec0ecc3 100644
--- a/arch/mips/include/asm/mach-loongson32/loongson1.h
+++ b/arch/mips/include/asm/mach-loongson32/loongson1.h
@@ -47,7 +47,6 @@

#include <regs-clk.h>
#include <regs-mux.h>
-#include <regs-pwm.h>
#include <regs-rtc.h>
#include <regs-wdt.h>

diff --git a/arch/mips/include/asm/mach-loongson32/regs-pwm.h b/arch/mips/include/asm/mach-loongson32/regs-pwm.h
deleted file mode 100644
index ec870c82d492..000000000000
--- a/arch/mips/include/asm/mach-loongson32/regs-pwm.h
+++ /dev/null
@@ -1,25 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
-/*
- * Copyright (c) 2014 Zhang, Keguang <keguang.zhang@xxxxxxxxx>
- *
- * Loongson 1 PWM Register Definitions.
- */
-
-#ifndef __ASM_MACH_LOONGSON32_REGS_PWM_H
-#define __ASM_MACH_LOONGSON32_REGS_PWM_H
-
-/* Loongson 1 PWM Timer Register Definitions */
-#define PWM_CNT 0x0
-#define PWM_HRC 0x4
-#define PWM_LRC 0x8
-#define PWM_CTRL 0xc
-
-/* PWM Control Register Bits */
-#define CNT_RST BIT(7)
-#define INT_SR BIT(6)
-#define INT_EN BIT(5)
-#define PWM_SINGLE BIT(4)
-#define PWM_OE BIT(3)
-#define CNT_EN BIT(0)
-
-#endif /* __ASM_MACH_LOONGSON32_REGS_PWM_H */
diff --git a/arch/mips/loongson32/Kconfig b/arch/mips/loongson32/Kconfig
index 2ef9da0016df..a7c500959577 100644
--- a/arch/mips/loongson32/Kconfig
+++ b/arch/mips/loongson32/Kconfig
@@ -35,41 +35,4 @@ config LOONGSON1_LS1C
select COMMON_CLK
endchoice

-menuconfig CEVT_CSRC_LS1X
- bool "Use PWM Timer for clockevent/clocksource"
- select MIPS_EXTERNAL_TIMER
- depends on CPU_LOONGSON32
- help
- This option changes the default clockevent/clocksource to PWM Timer,
- and is required by Loongson1 CPUFreq support.
-
- If unsure, say N.
-
-choice
- prompt "Select clockevent/clocksource"
- depends on CEVT_CSRC_LS1X
- default TIMER_USE_PWM0
-
-config TIMER_USE_PWM0
- bool "Use PWM Timer 0"
- help
- Use PWM Timer 0 as the default clockevent/clocksourcer.
-
-config TIMER_USE_PWM1
- bool "Use PWM Timer 1"
- help
- Use PWM Timer 1 as the default clockevent/clocksourcer.
-
-config TIMER_USE_PWM2
- bool "Use PWM Timer 2"
- help
- Use PWM Timer 2 as the default clockevent/clocksourcer.
-
-config TIMER_USE_PWM3
- bool "Use PWM Timer 3"
- help
- Use PWM Timer 3 as the default clockevent/clocksourcer.
-
-endchoice
-
endif # MACH_LOONGSON32
diff --git a/arch/mips/loongson32/common/time.c b/arch/mips/loongson32/common/time.c
index 965c04aa56fd..74ad2b17918d 100644
--- a/arch/mips/loongson32/common/time.c
+++ b/arch/mips/loongson32/common/time.c
@@ -5,208 +5,8 @@

#include <linux/clk.h>
#include <linux/of_clk.h>
-#include <linux/interrupt.h>
-#include <linux/sizes.h>
#include <asm/time.h>

-#include <loongson1.h>
-#include <platform.h>
-
-#ifdef CONFIG_CEVT_CSRC_LS1X
-
-#if defined(CONFIG_TIMER_USE_PWM1)
-#define LS1X_TIMER_BASE LS1X_PWM1_BASE
-#define LS1X_TIMER_IRQ LS1X_PWM1_IRQ
-
-#elif defined(CONFIG_TIMER_USE_PWM2)
-#define LS1X_TIMER_BASE LS1X_PWM2_BASE
-#define LS1X_TIMER_IRQ LS1X_PWM2_IRQ
-
-#elif defined(CONFIG_TIMER_USE_PWM3)
-#define LS1X_TIMER_BASE LS1X_PWM3_BASE
-#define LS1X_TIMER_IRQ LS1X_PWM3_IRQ
-
-#else
-#define LS1X_TIMER_BASE LS1X_PWM0_BASE
-#define LS1X_TIMER_IRQ LS1X_PWM0_IRQ
-#endif
-
-DEFINE_RAW_SPINLOCK(ls1x_timer_lock);
-
-static void __iomem *timer_reg_base;
-static uint32_t ls1x_jiffies_per_tick;
-
-static inline void ls1x_pwmtimer_set_period(uint32_t period)
-{
- __raw_writel(period, timer_reg_base + PWM_HRC);
- __raw_writel(period, timer_reg_base + PWM_LRC);
-}
-
-static inline void ls1x_pwmtimer_restart(void)
-{
- __raw_writel(0x0, timer_reg_base + PWM_CNT);
- __raw_writel(INT_EN | CNT_EN, timer_reg_base + PWM_CTRL);
-}
-
-void __init ls1x_pwmtimer_init(void)
-{
- timer_reg_base = ioremap(LS1X_TIMER_BASE, SZ_16);
- if (!timer_reg_base)
- panic("Failed to remap timer registers");
-
- ls1x_jiffies_per_tick = DIV_ROUND_CLOSEST(mips_hpt_frequency, HZ);
-
- ls1x_pwmtimer_set_period(ls1x_jiffies_per_tick);
- ls1x_pwmtimer_restart();
-}
-
-static u64 ls1x_clocksource_read(struct clocksource *cs)
-{
- unsigned long flags;
- int count;
- u32 jifs;
- static int old_count;
- static u32 old_jifs;
-
- raw_spin_lock_irqsave(&ls1x_timer_lock, flags);
- /*
- * Although our caller may have the read side of xtime_lock,
- * this is now a seqlock, and we are cheating in this routine
- * by having side effects on state that we cannot undo if
- * there is a collision on the seqlock and our caller has to
- * retry. (Namely, old_jifs and old_count.) So we must treat
- * jiffies as volatile despite the lock. We read jiffies
- * before latching the timer count to guarantee that although
- * the jiffies value might be older than the count (that is,
- * the counter may underflow between the last point where
- * jiffies was incremented and the point where we latch the
- * count), it cannot be newer.
- */
- jifs = jiffies;
- /* read the count */
- count = __raw_readl(timer_reg_base + PWM_CNT);
-
- /*
- * It's possible for count to appear to go the wrong way for this
- * reason:
- *
- * The timer counter underflows, but we haven't handled the resulting
- * interrupt and incremented jiffies yet.
- *
- * Previous attempts to handle these cases intelligently were buggy, so
- * we just do the simple thing now.
- */
- if (count < old_count && jifs == old_jifs)
- count = old_count;
-
- old_count = count;
- old_jifs = jifs;
-
- raw_spin_unlock_irqrestore(&ls1x_timer_lock, flags);
-
- return (u64) (jifs * ls1x_jiffies_per_tick) + count;
-}
-
-static struct clocksource ls1x_clocksource = {
- .name = "ls1x-pwmtimer",
- .read = ls1x_clocksource_read,
- .mask = CLOCKSOURCE_MASK(24),
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
-};
-
-static irqreturn_t ls1x_clockevent_isr(int irq, void *devid)
-{
- struct clock_event_device *cd = devid;
-
- ls1x_pwmtimer_restart();
- cd->event_handler(cd);
-
- return IRQ_HANDLED;
-}
-
-static int ls1x_clockevent_set_state_periodic(struct clock_event_device *cd)
-{
- raw_spin_lock(&ls1x_timer_lock);
- ls1x_pwmtimer_set_period(ls1x_jiffies_per_tick);
- ls1x_pwmtimer_restart();
- __raw_writel(INT_EN | CNT_EN, timer_reg_base + PWM_CTRL);
- raw_spin_unlock(&ls1x_timer_lock);
-
- return 0;
-}
-
-static int ls1x_clockevent_tick_resume(struct clock_event_device *cd)
-{
- raw_spin_lock(&ls1x_timer_lock);
- __raw_writel(INT_EN | CNT_EN, timer_reg_base + PWM_CTRL);
- raw_spin_unlock(&ls1x_timer_lock);
-
- return 0;
-}
-
-static int ls1x_clockevent_set_state_shutdown(struct clock_event_device *cd)
-{
- raw_spin_lock(&ls1x_timer_lock);
- __raw_writel(__raw_readl(timer_reg_base + PWM_CTRL) & ~CNT_EN,
- timer_reg_base + PWM_CTRL);
- raw_spin_unlock(&ls1x_timer_lock);
-
- return 0;
-}
-
-static int ls1x_clockevent_set_next(unsigned long evt,
- struct clock_event_device *cd)
-{
- raw_spin_lock(&ls1x_timer_lock);
- ls1x_pwmtimer_set_period(evt);
- ls1x_pwmtimer_restart();
- raw_spin_unlock(&ls1x_timer_lock);
-
- return 0;
-}
-
-static struct clock_event_device ls1x_clockevent = {
- .name = "ls1x-pwmtimer",
- .features = CLOCK_EVT_FEAT_PERIODIC,
- .rating = 300,
- .irq = LS1X_TIMER_IRQ,
- .set_next_event = ls1x_clockevent_set_next,
- .set_state_shutdown = ls1x_clockevent_set_state_shutdown,
- .set_state_periodic = ls1x_clockevent_set_state_periodic,
- .set_state_oneshot = ls1x_clockevent_set_state_shutdown,
- .tick_resume = ls1x_clockevent_tick_resume,
-};
-
-static void __init ls1x_time_init(void)
-{
- struct clock_event_device *cd = &ls1x_clockevent;
- int ret;
-
- if (!mips_hpt_frequency)
- panic("Invalid timer clock rate");
-
- ls1x_pwmtimer_init();
-
- clockevent_set_clock(cd, mips_hpt_frequency);
- cd->max_delta_ns = clockevent_delta2ns(0xffffff, cd);
- cd->max_delta_ticks = 0xffffff;
- cd->min_delta_ns = clockevent_delta2ns(0x000300, cd);
- cd->min_delta_ticks = 0x000300;
- cd->cpumask = cpumask_of(smp_processor_id());
- clockevents_register_device(cd);
-
- ls1x_clocksource.rating = 200 + mips_hpt_frequency / 10000000;
- ret = clocksource_register_hz(&ls1x_clocksource, mips_hpt_frequency);
- if (ret)
- panic(KERN_ERR "Failed to register clocksource: %d\n", ret);
-
- if (request_irq(LS1X_TIMER_IRQ, ls1x_clockevent_isr,
- IRQF_PERCPU | IRQF_TIMER, "ls1x-pwmtimer",
- &ls1x_clockevent))
- pr_err("Failed to register ls1x-pwmtimer interrupt\n");
-}
-#endif /* CONFIG_CEVT_CSRC_LS1X */
-
void __init plat_time_init(void)
{
struct clk *clk = NULL;
@@ -214,20 +14,10 @@ void __init plat_time_init(void)
/* initialize LS1X clocks */
of_clk_init(NULL);

-#ifdef CONFIG_CEVT_CSRC_LS1X
- /* setup LS1X PWM timer */
- clk = clk_get(NULL, "ls1x-pwmtimer");
- if (IS_ERR(clk))
- panic("unable to get timer clock, err=%ld", PTR_ERR(clk));
-
- mips_hpt_frequency = clk_get_rate(clk);
- ls1x_time_init();
-#else
/* setup mips r4k timer */
clk = clk_get(NULL, "cpu_clk");
if (IS_ERR(clk))
panic("unable to get cpu clock, err=%ld", PTR_ERR(clk));

mips_hpt_frequency = clk_get_rate(clk) / 2;
-#endif /* CONFIG_CEVT_CSRC_LS1X */
}
--
2.34.1