[PATCH v7 21/24] clk: Add driver for Maxim 77802 PMIC clocks

Javier Martinez Canillas
2014-07-04T20:24:24Z

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 <javier.martinez@collabora.co.uk>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
---

Changes since v6: None

Changes since v5: None

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 | 98 ++++++++++++++++++++++++++++++
include/dt-bindings/clock/maxim,max77802.h | 22 +++++++
4 files changed, 128 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..8808f2a 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 PMIC"
+ depends on MFD_MAX77686
+ 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..8e480c5
--- /dev/null
+++ b/drivers/clk/clk-max77802.c
@@ -0,0 +1,98 @@
+/*
+ * 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/max77686-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 max77686_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