Thread (42 messages) flat view 42 messages, 8 authors, 2014-07-02
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Revision v5 of 6 in this series; 1 review trailer.

Revisions (6)
  1. v3 [diff vs current]
  2. v4 [diff vs current]
  3. v5 current
  4. v6 [diff vs current]
  5. v7 [diff vs current]
  6. v8 [diff vs current]

[PATCH v5 11/14] clk: Add driver for Maxim 77802 PMIC clocks

From: Javier Martinez Canillas <hidden>
Date: 2014-06-26 18:17:02
Also in: linux-devicetree, linux-samsung-soc, lkml
Subsystem: common clk framework, maxim max77802 pmic regulator device driver, open firmware and flattened device tree bindings, the rest · Maintainers: Stephen Boyd, Brian Masney, Jerome Brunet, Javier Martinez Canillas, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds

The MAX77802 PMIC has two 32.768kHz Buffered Clock Outputs with
Low Jitter Mode. This patch adds support for these two clocks.

Signed-off-by: Javier Martinez Canillas <redacted>
Reviewed-by: Krzysztof Kozlowski <redacted>
---

Changes since v4: None

Changes since v3: None

Changes since v2: None

Changes since v1:
 - Use module_platform_driver() instead of having init/exit functions.
   Suggested by Mark Brown.
 - Use the generic maxim clock driver to reduce code duplication with
   clk-max77686.c driver.

 drivers/clk/Kconfig                        |  7 +++
 drivers/clk/Makefile                       |  1 +
 drivers/clk/clk-max77802.c                 | 99 ++++++++++++++++++++++++++++++
 include/dt-bindings/clock/maxim,max77802.h | 22 +++++++
 4 files changed, 129 insertions(+)
 create mode 100644 drivers/clk/clk-max77802.c
 create mode 100644 include/dt-bindings/clock/maxim,max77802.h
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 3fd4270..221260b 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -42,6 +42,13 @@ config COMMON_CLK_MAX77686
 	---help---
 	  This driver supports Maxim 77686 crystal oscillator clock. 
 
+config COMMON_CLK_MAX77802
+	tristate "Clock driver for Maxim 77802 MFD"
+	depends on MFD_MAX77802
+	select COMMON_CLK_MAX_GEN
+	---help---
+	  This driver supports Maxim 77802 crystal oscillator clock.
+
 config COMMON_CLK_SI5351
 	tristate "Clock driver for SiLabs 5351A/B/C"
 	depends on I2C
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 6c1aff6..520ff76 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_ARCH_HIGHBANK)		+= clk-highbank.o
 obj-$(CONFIG_MACH_LOONGSON1)		+= clk-ls1x.o
 obj-$(CONFIG_COMMON_CLK_MAX_GEN)	+= clk-max-gen.o
 obj-$(CONFIG_COMMON_CLK_MAX77686)	+= clk-max77686.o
+obj-$(CONFIG_COMMON_CLK_MAX77802)	+= clk-max77802.o
 obj-$(CONFIG_ARCH_MOXART)		+= clk-moxart.o
 obj-$(CONFIG_ARCH_NOMADIK)		+= clk-nomadik.o
 obj-$(CONFIG_ARCH_NSPIRE)		+= clk-nspire.o
diff --git a/drivers/clk/clk-max77802.c b/drivers/clk/clk-max77802.c
new file mode 100644
index 0000000..4253b44
--- /dev/null
+++ b/drivers/clk/clk-max77802.c
@@ -0,0 +1,99 @@
+/*
+ * clk-max77802.c - Clock driver for Maxim 77802
+ *
+ * Copyright (C) 2014 Google, Inc
+ *
+ * Copyright (C) 2012 Samsung Electornics
+ * Jonghwa Lee <jonghwa3.lee@samsung.com>
+ *
+ * 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.
+ *
+ * This driver is based on clk-max77686.c
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/max77802.h>
+#include <linux/mfd/max77802-private.h>
+#include <linux/clk-provider.h>
+#include <linux/mutex.h>
+#include <linux/clkdev.h>
+
+#include <dt-bindings/clock/maxim,max77802.h>
+#include "clk-max-gen.h"
+
+#define MAX77802_CLOCK_OPMODE_MASK	0x1
+#define MAX77802_CLOCK_LOW_JITTER_SHIFT 0x3
+
+static struct clk_init_data max77802_clks_init[MAX77802_CLKS_NUM] = {
+	[MAX77802_CLK_32K_AP] = {
+		.name = "32khz_ap",
+		.ops = &max_gen_clk_ops,
+		.flags = CLK_IS_ROOT,
+	},
+	[MAX77802_CLK_32K_CP] = {
+		.name = "32khz_cp",
+		.ops = &max_gen_clk_ops,
+		.flags = CLK_IS_ROOT,
+	},
+};
+
+static int max77802_clk_probe(struct platform_device *pdev)
+{
+	struct max77802_dev *iodev = dev_get_drvdata(pdev->dev.parent);
+	int ret;
+
+	ret = max_gen_clk_probe(pdev, iodev->regmap, MAX77802_REG_32KHZ,
+				max77802_clks_init, MAX77802_CLKS_NUM);
+
+	if (ret) {
+		dev_err(&pdev->dev, "generic probe failed %d\n", ret);
+		return ret;
+	}
+
+	/* Enable low-jitter mode on the 32khz clocks. */
+	ret = regmap_update_bits(iodev->regmap, MAX77802_REG_32KHZ,
+				 1 << MAX77802_CLOCK_LOW_JITTER_SHIFT,
+				 1 << MAX77802_CLOCK_LOW_JITTER_SHIFT);
+	if (ret < 0)
+		dev_err(&pdev->dev, "failed to enable low-jitter mode\n");
+
+	return ret;
+}
+
+static int max77802_clk_remove(struct platform_device *pdev)
+{
+	return max_gen_clk_remove(pdev, MAX77802_CLKS_NUM);
+}
+
+static const struct platform_device_id max77802_clk_id[] = {
+	{ "max77802-clk", 0},
+	{ },
+};
+MODULE_DEVICE_TABLE(platform, max77802_clk_id);
+
+static struct platform_driver max77802_clk_driver = {
+	.driver = {
+		.name  = "max77802-clk",
+		.owner = THIS_MODULE,
+	},
+	.probe = max77802_clk_probe,
+	.remove = max77802_clk_remove,
+	.id_table = max77802_clk_id,
+};
+
+module_platform_driver(max77802_clk_driver);
+
+MODULE_DESCRIPTION("MAXIM 77802 Clock Driver");
+MODULE_AUTHOR("Javier Martinez Canillas <javier.martinez@collabora.co.uk>");
+MODULE_LICENSE("GPL");
diff --git a/include/dt-bindings/clock/maxim,max77802.h b/include/dt-bindings/clock/maxim,max77802.h
new file mode 100644
index 0000000..997312e
--- /dev/null
+++ b/include/dt-bindings/clock/maxim,max77802.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2014 Google, Inc
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Device Tree binding constants clocks for the Maxim 77802 PMIC.
+ */
+
+#ifndef _DT_BINDINGS_CLOCK_MAXIM_MAX77802_CLOCK_H
+#define _DT_BINDINGS_CLOCK_MAXIM_MAX77802_CLOCK_H
+
+/* Fixed rate clocks. */
+
+#define MAX77802_CLK_32K_AP		0
+#define MAX77802_CLK_32K_CP		1
+
+/* Total number of clocks. */
+#define MAX77802_CLKS_NUM		(MAX77802_CLK_32K_CP + 1)
+
+#endif /* _DT_BINDINGS_CLOCK_MAXIM_MAX77802_CLOCK_H */
-- 
2.0.0.rc2
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