i.MX: Move GPT driver to drivers/clocksource

Move GPT driver to drivers/clocksource and rename it to
timer-imx-gpt.c to match Linux kernel as well as to keep all
clocksource drivers in a common location.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

3 files changed, 196 insertions, 0 deletions

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index ec1e622b48..1a33b2f0c9 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -74,3 +74,6 @@ config CLOCKSOURCE_ARMV8_TIMER
 config CLOCKSOURCE_ARM_GLOBAL_TIMER
 	bool
 	depends on ARM && CPU_V7
+config CLOCKSOURCE_IMX_GPT
+	def_bool y
+	depends on ARCH_IMX
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 51f6cb2f4a..ce4d74137a 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -13,3 +13,4 @@ obj-$(CONFIG_CLOCKSOURCE_ROCKCHIP)+= rk_timer.o
 obj-$(CONFIG_CLOCKSOURCE_ATMEL_PIT) += timer-atmel-pit.o
 obj-$(CONFIG_CLOCKSOURCE_ARMV8_TIMER) += armv8-timer.o
 obj-$(CONFIG_CLOCKSOURCE_ARM_GLOBAL_TIMER) += arm_global_timer.o
+obj-$(CONFIG_CLOCKSOURCE_IMX_GPT) += timer-imx-gpt.o
diff --git a/drivers/clocksource/timer-imx-gpt.c b/drivers/clocksource/timer-imx-gpt.c
new file mode 100644
index 0000000000..4d6c6c2b0b
--- /dev/null
+++ b/drivers/clocksource/timer-imx-gpt.c
@@ -0,0 +1,192 @@
+/*
+ * (C) Copyright 2002
+ * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Marius Groeger <mgroeger@sysgo.de>
+ *
+ * (C) Copyright 2002
+ * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Alex Zuepke <azu@sysgo.de>
+ *
+ * (C) Copyright 2002
+ * Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <common.h>
+#include <init.h>
+#include <clock.h>
+#include <errno.h>
+#include <of.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <notifier.h>
+#include <io.h>
+
+/* Part 1: Registers */
+# define GPT_TCTL   0x00
+# define GPT_TPRER  0x04
+
+/* Part 2: Bitfields */
+#define TCTL_SWR			(1 << 15)	/* Software reset */
+#define IMX1_TCTL_FRR			(1 << 8)	/* Freerun / restart */
+#define IMX31_TCTL_FRR			(1 << 9)	/* Freerun / restart */
+#define IMX1_TCTL_CLKSOURCE_PER		(1 << 1)	/* Clock source bit position */
+#define IMX31_TCTL_CLKSOURCE_IPG	(1 << 6)	/* Clock source bit position */
+#define IMX31_TCTL_CLKSOURCE_PER	(2 << 6)	/* Clock source bit position */
+#define TCTL_TEN			(1 << 0)	/* Timer enable */
+
+static struct clk *clk_gpt;
+
+struct imx_gpt_regs {
+	unsigned int tcn;
+	uint32_t tctl_val;
+};
+
+static struct imx_gpt_regs regs_imx1 = {
+	.tcn = 0x10,
+	.tctl_val = IMX1_TCTL_FRR | IMX1_TCTL_CLKSOURCE_PER | TCTL_TEN,
+};
+
+static struct imx_gpt_regs regs_imx31 = {
+	.tcn = 0x24,
+	.tctl_val = IMX31_TCTL_FRR | IMX31_TCTL_CLKSOURCE_PER | TCTL_TEN,
+};
+
+static struct imx_gpt_regs *regs;
+static void __iomem *timer_base;
+
+static uint64_t imx_clocksource_read(void)
+{
+	return readl(timer_base + regs->tcn);
+}
+
+static struct clocksource cs = {
+	.read	= imx_clocksource_read,
+	.mask	= CLOCKSOURCE_MASK(32),
+	.shift	= 10,
+};
+
+static int imx_clocksource_clock_change(struct notifier_block *nb, unsigned long event, void *data)
+{
+	cs.mult = clocksource_hz2mult(clk_get_rate(clk_gpt), cs.shift);
+	return 0;
+}
+
+static struct notifier_block imx_clock_notifier = {
+	.notifier_call = imx_clocksource_clock_change,
+};
+
+static int imx_gpt_probe(struct device_d *dev)
+{
+	struct resource *iores;
+	int i;
+	int ret;
+	unsigned long rate;
+
+	/* one timer is enough */
+	if (timer_base)
+		return 0;
+
+	ret = dev_get_drvdata(dev, (const void **)&regs);
+	if (ret)
+		return ret;
+
+	iores = dev_request_mem_resource(dev, 0);
+	if (IS_ERR(iores))
+		return PTR_ERR(iores);
+	timer_base = IOMEM(iores->start);
+
+	/* setup GP Timer 1 */
+	writel(TCTL_SWR, timer_base + GPT_TCTL);
+
+	for (i = 0; i < 100; i++)
+		writel(0, timer_base + GPT_TCTL); /* We have no udelay by now */
+
+	clk_gpt = clk_get(dev, "per");
+	if (IS_ERR(clk_gpt)) {
+		rate = 20000000;
+		dev_err(dev, "failed to get clock, assume %lu Hz\n", rate);
+	} else {
+		rate = clk_get_rate(clk_gpt);
+		if (!rate) {
+			dev_err(dev, "clock reports rate == 0\n");
+			return -EIO;
+		}
+	}
+
+	writel(0, timer_base + GPT_TPRER);
+	writel(regs->tctl_val, timer_base + GPT_TCTL);
+
+	cs.mult = clocksource_hz2mult(rate, cs.shift);
+
+	init_clock(&cs);
+
+	clock_register_client(&imx_clock_notifier);
+
+	return 0;
+}
+
+static __maybe_unused struct of_device_id imx_gpt_dt_ids[] = {
+	{
+		.compatible = "fsl,imx1-gpt",
+		.data = &regs_imx1,
+	}, {
+		.compatible = "fsl,imx21-gpt",
+		.data = &regs_imx1,
+	}, {
+		.compatible = "fsl,imx31-gpt",
+		.data = &regs_imx31,
+	}, {
+		.compatible = "fsl,imx6q-gpt",
+		.data = &regs_imx31,
+	}, {
+		.compatible = "fsl,imx6dl-gpt",
+		.data = &regs_imx31,
+	}, {
+		.compatible = "fsl,imx6ul-gpt",
+		.data = &regs_imx31,
+	}, {
+		.compatible = "fsl,imx7d-gpt",
+		.data = &regs_imx31,
+	}, {
+		/* sentinel */
+	}
+};
+
+static struct platform_device_id imx_gpt_ids[] = {
+	{
+		.name = "imx1-gpt",
+		.driver_data = (unsigned long)&regs_imx1,
+	}, {
+		.name = "imx31-gpt",
+		.driver_data = (unsigned long)&regs_imx31,
+	}, {
+		/* sentinel */
+	},
+};
+
+static struct driver_d imx_gpt_driver = {
+	.name = "imx-gpt",
+	.probe = imx_gpt_probe,
+	.of_compatible = DRV_OF_COMPAT(imx_gpt_dt_ids),
+	.id_table = imx_gpt_ids,
+};
+
+static int imx_gpt_init(void)
+{
+	return platform_driver_register(&imx_gpt_driver);
+}
+postcore_initcall(imx_gpt_init);