[tip: timers/core] clocksource/drivers/timer-mediatek: Split out CPUXGPT timers
From: tip-bot2 for AngeloGioacchino Del Regno
Date: Wed Apr 26 2023 - 05:14:24 EST
The following commit has been merged into the timers/core branch of tip:
Commit-ID: 49d576ea72a4fa5be15717babfa308b70b2bc5a4
Gitweb: https://git.kernel.org/tip/49d576ea72a4fa5be15717babfa308b70b2bc5a4
Author: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
AuthorDate: Thu, 09 Mar 2023 11:39:13 +01:00
Committer: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
CommitterDate: Mon, 24 Apr 2023 16:56:13 +02:00
clocksource/drivers/timer-mediatek: Split out CPUXGPT timers
On MediaTek platforms, CPUXGPT is the source for the AArch64 System
Timer, read through CNTVCT_EL0.
The handling for starting this timer ASAP was introduced in commit
327e93cf9a59 ("clocksource/drivers/timer-mediatek: Implement CPUXGPT timers")
which description also contains an important full explanation of the
reasons why this driver is necessary and cannot be a module.
In preparation for an eventual conversion of timer-mediatek to a
platform_driver that would be possibly built as a module, split out
the CPUXGPT timers driver to a new timer-mediatek-cpux.c driver.
This commit brings no functional changes.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Reviewed-by: Walter Chang <walter.chang@xxxxxxxxxxxx>
Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230309103913.116775-1-angelogioacchino.delregno@xxxxxxxxxxxxx
---
drivers/clocksource/Kconfig | 9 +-
drivers/clocksource/Makefile | 1 +-
drivers/clocksource/timer-mediatek-cpux.c | 140 +++++++++++++++++++++-
drivers/clocksource/timer-mediatek.c | 114 +-----------------
4 files changed, 150 insertions(+), 114 deletions(-)
create mode 100644 drivers/clocksource/timer-mediatek-cpux.c
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 5fc8f0e..526382d 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -479,6 +479,15 @@ config MTK_TIMER
help
Support for Mediatek timer driver.
+config MTK_CPUX_TIMER
+ bool "MediaTek CPUX timer driver" if COMPILE_TEST
+ depends on HAS_IOMEM
+ default ARCH_MEDIATEK
+ select TIMER_OF
+ select CLKSRC_MMIO
+ help
+ Support for MediaTek CPUXGPT timer driver.
+
config SPRD_TIMER
bool "Spreadtrum timer driver" if EXPERT
depends on HAS_IOMEM
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 64ab547..f12d398 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -51,6 +51,7 @@ obj-$(CONFIG_FSL_FTM_TIMER) += timer-fsl-ftm.o
obj-$(CONFIG_VF_PIT_TIMER) += timer-vf-pit.o
obj-$(CONFIG_CLKSRC_QCOM) += timer-qcom.o
obj-$(CONFIG_MTK_TIMER) += timer-mediatek.o
+obj-$(CONFIG_MTK_CPUX_TIMER) += timer-mediatek-cpux.o
obj-$(CONFIG_CLKSRC_PISTACHIO) += timer-pistachio.o
obj-$(CONFIG_CLKSRC_TI_32K) += timer-ti-32k.o
obj-$(CONFIG_OXNAS_RPS_TIMER) += timer-oxnas-rps.o
diff --git a/drivers/clocksource/timer-mediatek-cpux.c b/drivers/clocksource/timer-mediatek-cpux.c
new file mode 100644
index 0000000..a8e3df4
--- /dev/null
+++ b/drivers/clocksource/timer-mediatek-cpux.c
@@ -0,0 +1,140 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * MediaTek SoCs CPUX General Purpose Timer handling
+ *
+ * Based on timer-mediatek.c:
+ * Copyright (C) 2014 Matthias Brugger <matthias.bgg@xxxxxxxxx>
+ *
+ * Copyright (C) 2022 Collabora Ltd.
+ * AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/interrupt.h>
+#include <linux/irqreturn.h>
+#include <linux/sched_clock.h>
+#include <linux/slab.h>
+#include "timer-of.h"
+
+#define TIMER_SYNC_TICKS 3
+
+/* cpux mcusys wrapper */
+#define CPUX_CON_REG 0x0
+#define CPUX_IDX_REG 0x4
+
+/* cpux */
+#define CPUX_IDX_GLOBAL_CTRL 0x0
+ #define CPUX_ENABLE BIT(0)
+ #define CPUX_CLK_DIV_MASK GENMASK(10, 8)
+ #define CPUX_CLK_DIV1 BIT(8)
+ #define CPUX_CLK_DIV2 BIT(9)
+ #define CPUX_CLK_DIV4 BIT(10)
+#define CPUX_IDX_GLOBAL_IRQ 0x30
+
+static u32 mtk_cpux_readl(u32 reg_idx, struct timer_of *to)
+{
+ writel(reg_idx, timer_of_base(to) + CPUX_IDX_REG);
+ return readl(timer_of_base(to) + CPUX_CON_REG);
+}
+
+static void mtk_cpux_writel(u32 val, u32 reg_idx, struct timer_of *to)
+{
+ writel(reg_idx, timer_of_base(to) + CPUX_IDX_REG);
+ writel(val, timer_of_base(to) + CPUX_CON_REG);
+}
+
+static void mtk_cpux_set_irq(struct timer_of *to, bool enable)
+{
+ const unsigned long *irq_mask = cpumask_bits(cpu_possible_mask);
+ u32 val;
+
+ val = mtk_cpux_readl(CPUX_IDX_GLOBAL_IRQ, to);
+
+ if (enable)
+ val |= *irq_mask;
+ else
+ val &= ~(*irq_mask);
+
+ mtk_cpux_writel(val, CPUX_IDX_GLOBAL_IRQ, to);
+}
+
+static int mtk_cpux_clkevt_shutdown(struct clock_event_device *clkevt)
+{
+ /* Clear any irq */
+ mtk_cpux_set_irq(to_timer_of(clkevt), false);
+
+ /*
+ * Disabling CPUXGPT timer will crash the platform, especially
+ * if Trusted Firmware is using it (usually, for sleep states),
+ * so we only mask the IRQ and call it a day.
+ */
+ return 0;
+}
+
+static int mtk_cpux_clkevt_resume(struct clock_event_device *clkevt)
+{
+ mtk_cpux_set_irq(to_timer_of(clkevt), true);
+ return 0;
+}
+
+static struct timer_of to = {
+ /*
+ * There are per-cpu interrupts for the CPUX General Purpose Timer
+ * but since this timer feeds the AArch64 System Timer we can rely
+ * on the CPU timer PPIs as well, so we don't declare TIMER_OF_IRQ.
+ */
+ .flags = TIMER_OF_BASE | TIMER_OF_CLOCK,
+
+ .clkevt = {
+ .name = "mtk-cpuxgpt",
+ .cpumask = cpu_possible_mask,
+ .rating = 10,
+ .set_state_shutdown = mtk_cpux_clkevt_shutdown,
+ .tick_resume = mtk_cpux_clkevt_resume,
+ },
+};
+
+static int __init mtk_cpux_init(struct device_node *node)
+{
+ u32 freq, val;
+ int ret;
+
+ /* If this fails, bad things are about to happen... */
+ ret = timer_of_init(node, &to);
+ if (ret) {
+ WARN(1, "Cannot start CPUX timers.\n");
+ return ret;
+ }
+
+ /*
+ * Check if we're given a clock with the right frequency for this
+ * timer, otherwise warn but keep going with the setup anyway, as
+ * that makes it possible to still boot the kernel, even though
+ * it may not work correctly (random lockups, etc).
+ * The reason behind this is that having an early UART may not be
+ * possible for everyone and this gives a chance to retrieve kmsg
+ * for eventual debugging even on consumer devices.
+ */
+ freq = timer_of_rate(&to);
+ if (freq > 13000000)
+ WARN(1, "Requested unsupported timer frequency %u\n", freq);
+
+ /* Clock input is 26MHz, set DIV2 to achieve 13MHz clock */
+ val = mtk_cpux_readl(CPUX_IDX_GLOBAL_CTRL, &to);
+ val &= ~CPUX_CLK_DIV_MASK;
+ val |= CPUX_CLK_DIV2;
+ mtk_cpux_writel(val, CPUX_IDX_GLOBAL_CTRL, &to);
+
+ /* Enable all CPUXGPT timers */
+ val = mtk_cpux_readl(CPUX_IDX_GLOBAL_CTRL, &to);
+ mtk_cpux_writel(val | CPUX_ENABLE, CPUX_IDX_GLOBAL_CTRL, &to);
+
+ clockevents_config_and_register(&to.clkevt, timer_of_rate(&to),
+ TIMER_SYNC_TICKS, 0xffffffff);
+
+ return 0;
+}
+TIMER_OF_DECLARE(mtk_mt6795, "mediatek,mt6795-systimer", mtk_cpux_init);
diff --git a/drivers/clocksource/timer-mediatek.c b/drivers/clocksource/timer-mediatek.c
index d5b29fd..7bcb4a3 100644
--- a/drivers/clocksource/timer-mediatek.c
+++ b/drivers/clocksource/timer-mediatek.c
@@ -22,19 +22,6 @@
#define TIMER_SYNC_TICKS (3)
-/* cpux mcusys wrapper */
-#define CPUX_CON_REG 0x0
-#define CPUX_IDX_REG 0x4
-
-/* cpux */
-#define CPUX_IDX_GLOBAL_CTRL 0x0
- #define CPUX_ENABLE BIT(0)
- #define CPUX_CLK_DIV_MASK GENMASK(10, 8)
- #define CPUX_CLK_DIV1 BIT(8)
- #define CPUX_CLK_DIV2 BIT(9)
- #define CPUX_CLK_DIV4 BIT(10)
-#define CPUX_IDX_GLOBAL_IRQ 0x30
-
/* gpt */
#define GPT_IRQ_EN_REG 0x00
#define GPT_IRQ_ENABLE(val) BIT((val) - 1)
@@ -85,52 +72,6 @@
static void __iomem *gpt_sched_reg __read_mostly;
-static u32 mtk_cpux_readl(u32 reg_idx, struct timer_of *to)
-{
- writel(reg_idx, timer_of_base(to) + CPUX_IDX_REG);
- return readl(timer_of_base(to) + CPUX_CON_REG);
-}
-
-static void mtk_cpux_writel(u32 val, u32 reg_idx, struct timer_of *to)
-{
- writel(reg_idx, timer_of_base(to) + CPUX_IDX_REG);
- writel(val, timer_of_base(to) + CPUX_CON_REG);
-}
-
-static void mtk_cpux_set_irq(struct timer_of *to, bool enable)
-{
- const unsigned long *irq_mask = cpumask_bits(cpu_possible_mask);
- u32 val;
-
- val = mtk_cpux_readl(CPUX_IDX_GLOBAL_IRQ, to);
-
- if (enable)
- val |= *irq_mask;
- else
- val &= ~(*irq_mask);
-
- mtk_cpux_writel(val, CPUX_IDX_GLOBAL_IRQ, to);
-}
-
-static int mtk_cpux_clkevt_shutdown(struct clock_event_device *clkevt)
-{
- /* Clear any irq */
- mtk_cpux_set_irq(to_timer_of(clkevt), false);
-
- /*
- * Disabling CPUXGPT timer will crash the platform, especially
- * if Trusted Firmware is using it (usually, for sleep states),
- * so we only mask the IRQ and call it a day.
- */
- return 0;
-}
-
-static int mtk_cpux_clkevt_resume(struct clock_event_device *clkevt)
-{
- mtk_cpux_set_irq(to_timer_of(clkevt), true);
- return 0;
-}
-
static void mtk_syst_ack_irq(struct timer_of *to)
{
/* Clear and disable interrupt */
@@ -340,60 +281,6 @@ static struct timer_of to = {
},
};
-static int __init mtk_cpux_init(struct device_node *node)
-{
- static struct timer_of to_cpux;
- u32 freq, val;
- int ret;
-
- /*
- * There are per-cpu interrupts for the CPUX General Purpose Timer
- * but since this timer feeds the AArch64 System Timer we can rely
- * on the CPU timer PPIs as well, so we don't declare TIMER_OF_IRQ.
- */
- to_cpux.flags = TIMER_OF_BASE | TIMER_OF_CLOCK;
- to_cpux.clkevt.name = "mtk-cpuxgpt";
- to_cpux.clkevt.rating = 10;
- to_cpux.clkevt.cpumask = cpu_possible_mask;
- to_cpux.clkevt.set_state_shutdown = mtk_cpux_clkevt_shutdown;
- to_cpux.clkevt.tick_resume = mtk_cpux_clkevt_resume;
-
- /* If this fails, bad things are about to happen... */
- ret = timer_of_init(node, &to_cpux);
- if (ret) {
- WARN(1, "Cannot start CPUX timers.\n");
- return ret;
- }
-
- /*
- * Check if we're given a clock with the right frequency for this
- * timer, otherwise warn but keep going with the setup anyway, as
- * that makes it possible to still boot the kernel, even though
- * it may not work correctly (random lockups, etc).
- * The reason behind this is that having an early UART may not be
- * possible for everyone and this gives a chance to retrieve kmsg
- * for eventual debugging even on consumer devices.
- */
- freq = timer_of_rate(&to_cpux);
- if (freq > 13000000)
- WARN(1, "Requested unsupported timer frequency %u\n", freq);
-
- /* Clock input is 26MHz, set DIV2 to achieve 13MHz clock */
- val = mtk_cpux_readl(CPUX_IDX_GLOBAL_CTRL, &to_cpux);
- val &= ~CPUX_CLK_DIV_MASK;
- val |= CPUX_CLK_DIV2;
- mtk_cpux_writel(val, CPUX_IDX_GLOBAL_CTRL, &to_cpux);
-
- /* Enable all CPUXGPT timers */
- val = mtk_cpux_readl(CPUX_IDX_GLOBAL_CTRL, &to_cpux);
- mtk_cpux_writel(val | CPUX_ENABLE, CPUX_IDX_GLOBAL_CTRL, &to_cpux);
-
- clockevents_config_and_register(&to_cpux.clkevt, timer_of_rate(&to_cpux),
- TIMER_SYNC_TICKS, 0xffffffff);
-
- return 0;
-}
-
static int __init mtk_syst_init(struct device_node *node)
{
int ret;
@@ -452,4 +339,3 @@ static int __init mtk_gpt_init(struct device_node *node)
}
TIMER_OF_DECLARE(mtk_mt6577, "mediatek,mt6577-timer", mtk_gpt_init);
TIMER_OF_DECLARE(mtk_mt6765, "mediatek,mt6765-timer", mtk_syst_init);
-TIMER_OF_DECLARE(mtk_mt6795, "mediatek,mt6795-systimer", mtk_cpux_init);