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Subject[PATCH 04/21] clocksource: Add driver for the Ingenic JZ47xx OST
Date
From: Maarten ter Huurne <maarten@treewalker.org>

OST is the OS Timer, a 64-bit timer/counter with buffered reading.

SoCs before the JZ4770 had (if any) a 32-bit OST; the JZ4770 and
JZ4780 have a 64-bit OST.

This driver will register both a clocksource and a sched_clock to the
system.

Signed-off-by: Maarten ter Huurne <maarten@treewalker.org>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200212180408.30872-1-paul@crapouillou.net
---
drivers/clocksource/Kconfig | 8 ++
drivers/clocksource/Makefile | 1 +
drivers/clocksource/ingenic-ost.c | 189 ++++++++++++++++++++++++++++++
3 files changed, 198 insertions(+)
create mode 100644 drivers/clocksource/ingenic-ost.c

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index cc909e465823..f2142e6bbea3 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -697,6 +697,14 @@ config INGENIC_TIMER
help
Support for the timer/counter unit of the Ingenic JZ SoCs.

+config INGENIC_OST
+ bool "Clocksource for Ingenic OS Timer"
+ depends on MIPS || COMPILE_TEST
+ depends on COMMON_CLK
+ select MFD_SYSCON
+ help
+ Support for the Operating System Timer of the Ingenic JZ SoCs.
+
config MICROCHIP_PIT64B
bool "Microchip PIT64B support"
depends on OF || COMPILE_TEST
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 713686faa549..641ba5383ab5 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -80,6 +80,7 @@ obj-$(CONFIG_ASM9260_TIMER) += asm9260_timer.o
obj-$(CONFIG_H8300_TMR8) += h8300_timer8.o
obj-$(CONFIG_H8300_TMR16) += h8300_timer16.o
obj-$(CONFIG_H8300_TPU) += h8300_tpu.o
+obj-$(CONFIG_INGENIC_OST) += ingenic-ost.o
obj-$(CONFIG_INGENIC_TIMER) += ingenic-timer.o
obj-$(CONFIG_CLKSRC_ST_LPC) += clksrc_st_lpc.o
obj-$(CONFIG_X86_NUMACHIP) += numachip.o
diff --git a/drivers/clocksource/ingenic-ost.c b/drivers/clocksource/ingenic-ost.c
new file mode 100644
index 000000000000..029efc2731b4
--- /dev/null
+++ b/drivers/clocksource/ingenic-ost.c
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * JZ47xx SoCs TCU Operating System Timer driver
+ *
+ * Copyright (C) 2016 Maarten ter Huurne <maarten@treewalker.org>
+ * Copyright (C) 2020 Paul Cercueil <paul@crapouillou.net>
+ */
+
+#include <linux/clk.h>
+#include <linux/clocksource.h>
+#include <linux/mfd/ingenic-tcu.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/regmap.h>
+#include <linux/sched_clock.h>
+
+#define TCU_OST_TCSR_MASK 0xffc0
+#define TCU_OST_TCSR_CNT_MD BIT(15)
+
+#define TCU_OST_CHANNEL 15
+
+/*
+ * The TCU_REG_OST_CNT{L,R} from <linux/mfd/ingenic-tcu.h> are only for the
+ * regmap; these are for use with the __iomem pointer.
+ */
+#define OST_REG_CNTL 0x4
+#define OST_REG_CNTH 0x8
+
+struct ingenic_ost_soc_info {
+ bool is64bit;
+};
+
+struct ingenic_ost {
+ void __iomem *regs;
+ struct clk *clk;
+
+ struct clocksource cs;
+};
+
+static struct ingenic_ost *ingenic_ost;
+
+static u64 notrace ingenic_ost_read_cntl(void)
+{
+ /* Read using __iomem pointer instead of regmap to avoid locking */
+ return readl(ingenic_ost->regs + OST_REG_CNTL);
+}
+
+static u64 notrace ingenic_ost_read_cnth(void)
+{
+ /* Read using __iomem pointer instead of regmap to avoid locking */
+ return readl(ingenic_ost->regs + OST_REG_CNTH);
+}
+
+static u64 notrace ingenic_ost_clocksource_readl(struct clocksource *cs)
+{
+ return ingenic_ost_read_cntl();
+}
+
+static u64 notrace ingenic_ost_clocksource_readh(struct clocksource *cs)
+{
+ return ingenic_ost_read_cnth();
+}
+
+static int __init ingenic_ost_probe(struct platform_device *pdev)
+{
+ const struct ingenic_ost_soc_info *soc_info;
+ struct device *dev = &pdev->dev;
+ struct ingenic_ost *ost;
+ struct clocksource *cs;
+ struct regmap *map;
+ unsigned long rate;
+ int err;
+
+ soc_info = device_get_match_data(dev);
+ if (!soc_info)
+ return -EINVAL;
+
+ ost = devm_kzalloc(dev, sizeof(*ost), GFP_KERNEL);
+ if (!ost)
+ return -ENOMEM;
+
+ ingenic_ost = ost;
+
+ ost->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(ost->regs))
+ return PTR_ERR(ost->regs);
+
+ map = device_node_to_regmap(dev->parent->of_node);
+ if (!map) {
+ dev_err(dev, "regmap not found");
+ return -EINVAL;
+ }
+
+ ost->clk = devm_clk_get(dev, "ost");
+ if (IS_ERR(ost->clk))
+ return PTR_ERR(ost->clk);
+
+ err = clk_prepare_enable(ost->clk);
+ if (err)
+ return err;
+
+ /* Clear counter high/low registers */
+ if (soc_info->is64bit)
+ regmap_write(map, TCU_REG_OST_CNTL, 0);
+ regmap_write(map, TCU_REG_OST_CNTH, 0);
+
+ /* Don't reset counter at compare value. */
+ regmap_update_bits(map, TCU_REG_OST_TCSR,
+ TCU_OST_TCSR_MASK, TCU_OST_TCSR_CNT_MD);
+
+ rate = clk_get_rate(ost->clk);
+
+ /* Enable OST TCU channel */
+ regmap_write(map, TCU_REG_TESR, BIT(TCU_OST_CHANNEL));
+
+ cs = &ost->cs;
+ cs->name = "ingenic-ost";
+ cs->rating = 320;
+ cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
+ cs->mask = CLOCKSOURCE_MASK(32);
+
+ if (soc_info->is64bit)
+ cs->read = ingenic_ost_clocksource_readl;
+ else
+ cs->read = ingenic_ost_clocksource_readh;
+
+ err = clocksource_register_hz(cs, rate);
+ if (err) {
+ dev_err(dev, "clocksource registration failed");
+ clk_disable_unprepare(ost->clk);
+ return err;
+ }
+
+ if (soc_info->is64bit)
+ sched_clock_register(ingenic_ost_read_cntl, 32, rate);
+ else
+ sched_clock_register(ingenic_ost_read_cnth, 32, rate);
+
+ return 0;
+}
+
+static int __maybe_unused ingenic_ost_suspend(struct device *dev)
+{
+ struct ingenic_ost *ost = dev_get_drvdata(dev);
+
+ clk_disable(ost->clk);
+
+ return 0;
+}
+
+static int __maybe_unused ingenic_ost_resume(struct device *dev)
+{
+ struct ingenic_ost *ost = dev_get_drvdata(dev);
+
+ return clk_enable(ost->clk);
+}
+
+static const struct dev_pm_ops __maybe_unused ingenic_ost_pm_ops = {
+ /* _noirq: We want the OST clock to be gated last / ungated first */
+ .suspend_noirq = ingenic_ost_suspend,
+ .resume_noirq = ingenic_ost_resume,
+};
+
+static const struct ingenic_ost_soc_info jz4725b_ost_soc_info = {
+ .is64bit = false,
+};
+
+static const struct ingenic_ost_soc_info jz4770_ost_soc_info = {
+ .is64bit = true,
+};
+
+static const struct of_device_id ingenic_ost_of_match[] = {
+ { .compatible = "ingenic,jz4725b-ost", .data = &jz4725b_ost_soc_info, },
+ { .compatible = "ingenic,jz4770-ost", .data = &jz4770_ost_soc_info, },
+ { }
+};
+
+static struct platform_driver ingenic_ost_driver = {
+ .driver = {
+ .name = "ingenic-ost",
+#ifdef CONFIG_PM_SUSPEND
+ .pm = &ingenic_ost_pm_ops,
+#endif
+ .of_match_table = ingenic_ost_of_match,
+ },
+};
+builtin_platform_driver_probe(ingenic_ost_driver, ingenic_ost_probe);
--
2.17.1
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