[PATCH 3/5] clk: Add driver for Maxim 77802 PMIC clocks
From: Javier Martinez Canillas
Date: Mon Jun 09 2014 - 05:39:49 EST
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@xxxxxxxxxxxxxxx>
---
.../devicetree/bindings/clock/maxim,max77802.txt | 40 ++++
drivers/clk/Kconfig | 6 +
drivers/clk/Makefile | 1 +
drivers/clk/clk-max77802.c | 253 +++++++++++++++++++++
drivers/mfd/max77802.c | 3 +
include/dt-bindings/clock/maxim,max77802.h | 22 ++
6 files changed, 325 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/maxim,max77802.txt
create mode 100644 drivers/clk/clk-max77802.c
create mode 100644 include/dt-bindings/clock/maxim,max77802.h
diff --git a/Documentation/devicetree/bindings/clock/maxim,max77802.txt b/Documentation/devicetree/bindings/clock/maxim,max77802.txt
new file mode 100644
index 0000000..1d3fb64
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/maxim,max77802.txt
@@ -0,0 +1,40 @@
+Binding for Maxim MAX77802 32k clock generator block
+
+This is a part of device tree bindings of MAX77802 multi-function device.
+More information can be found in bindings/mfd/max77802.txt file.
+
+The MAX77802 contains two 32.768khz clock outputs that can be controlled
+(gated/ungated) over I2C.
+
+Following properties should be presend in main device node of the MFD chip.
+
+Required properties:
+
+- #clock-cells: from common clock binding; shall be set to 1.
+
+Each clock is assigned an identifier and client nodes can use this identifier
+to specify the clock which they consume.
+
+Clocks are defined as preprocessor macros in dt-bindings/clock/maxim,max77802.h
+header and can be used in device tree sources.
+
+Example: Node of the MFD chip
+
+ max77802: max77802@09 {
+ compatible = "maxim,max77802";
+ interrupt-parent = <&wakeup_eint>;
+ interrupts = <26 0>;
+ reg = <0x09>;
+ #clock-cells = <1>;
+
+ /* ... */
+ };
+
+Example: Clock consumer node
+
+ foo@0 {
+ compatible = "bar,foo";
+ /* ... */
+ clock-names = "32khz_ap";
+ clocks = <&max77802 MAX77802_CLK_32K_AP>;
+ };
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 9f9c5ae..74c71a4 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -38,6 +38,12 @@ 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
+ ---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 567f102..677692f 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_ARCH_EFM32) += clk-efm32gg.o
obj-$(CONFIG_ARCH_HIGHBANK) += clk-highbank.o
obj-$(CONFIG_MACH_LOONGSON1) += clk-ls1x.o
obj-$(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..a98fc29
--- /dev/null
+++ b/drivers/clk/clk-max77802.c
@@ -0,0 +1,253 @@
+/*
+ * clk-max77802.c - Clock driver for Maxim 77802
+ *
+ * Copyright (C) 2014 Google, Inc
+ *
+ * Copyright (C) 2012 Samsung Electornics
+ * Jonghwa Lee <jonghwa3.lee@xxxxxxxxxxx>
+ *
+ * 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>
+
+#define MAX77802_CLOCK_OPMODE_MASK 0x1
+#define MAX77802_CLOCK_LOW_JITTER_SHIFT 0x3
+
+struct max77802_clk {
+ struct max77802_dev *iodev;
+ u32 mask;
+ struct clk_hw hw;
+ struct clk_lookup *lookup;
+};
+
+static struct max77802_clk *to_max77802_clk(struct clk_hw *hw)
+{
+ return container_of(hw, struct max77802_clk, hw);
+}
+
+static int max77802_clk_prepare(struct clk_hw *hw)
+{
+ struct max77802_clk *max77802 = to_max77802_clk(hw);
+
+ return regmap_update_bits(max77802->iodev->regmap,
+ MAX77802_REG_32KHZ, max77802->mask,
+ max77802->mask);
+}
+
+static void max77802_clk_unprepare(struct clk_hw *hw)
+{
+ struct max77802_clk *max77802 = to_max77802_clk(hw);
+
+ regmap_update_bits(max77802->iodev->regmap,
+ MAX77802_REG_32KHZ, max77802->mask, ~max77802->mask);
+}
+
+static int max77802_clk_is_prepared(struct clk_hw *hw)
+{
+ struct max77802_clk *max77802 = to_max77802_clk(hw);
+ int ret;
+ u32 val;
+
+ ret = regmap_read(max77802->iodev->regmap,
+ MAX77802_REG_32KHZ, &val);
+
+ if (ret < 0)
+ return -EINVAL;
+
+ return val & max77802->mask;
+}
+
+static unsigned long max77802_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ return 32768;
+}
+
+static struct clk_ops max77802_clk_ops = {
+ .prepare = max77802_clk_prepare,
+ .unprepare = max77802_clk_unprepare,
+ .is_prepared = max77802_clk_is_prepared,
+ .recalc_rate = max77802_recalc_rate,
+};
+
+static struct clk_init_data max77802_clks_init[MAX77802_CLKS_NUM] = {
+ [MAX77802_CLK_32K_AP] = {
+ .name = "32khz_ap",
+ .ops = &max77802_clk_ops,
+ .flags = CLK_IS_ROOT,
+ },
+ [MAX77802_CLK_32K_CP] = {
+ .name = "32khz_cp",
+ .ops = &max77802_clk_ops,
+ .flags = CLK_IS_ROOT,
+ },
+};
+
+static struct clk *max77802_clk_register(struct device *dev,
+ struct max77802_clk *max77802)
+{
+ struct clk *clk;
+ struct clk_hw *hw = &max77802->hw;
+
+ clk = clk_register(dev, hw);
+ if (IS_ERR(clk))
+ return clk;
+
+ max77802->lookup = kzalloc(sizeof(struct clk_lookup), GFP_KERNEL);
+ if (!max77802->lookup)
+ return ERR_PTR(-ENOMEM);
+
+ max77802->lookup->con_id = hw->init->name;
+ max77802->lookup->clk = clk;
+
+ clkdev_add(max77802->lookup);
+
+ return clk;
+}
+
+static int max77802_clk_probe(struct platform_device *pdev)
+{
+ struct max77802_dev *iodev = dev_get_drvdata(pdev->dev.parent);
+ struct max77802_clk *max77802_clks[MAX77802_CLKS_NUM];
+ struct clk **clocks;
+ int i, ret;
+
+ clocks = devm_kzalloc(&pdev->dev, sizeof(struct clk *)
+ * MAX77802_CLKS_NUM, GFP_KERNEL);
+ if (!clocks)
+ return -ENOMEM;
+
+ for (i = 0; i < MAX77802_CLKS_NUM; i++) {
+ max77802_clks[i] = devm_kzalloc(&pdev->dev,
+ sizeof(struct max77802_clk), GFP_KERNEL);
+ if (!max77802_clks[i])
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < MAX77802_CLKS_NUM; i++) {
+ max77802_clks[i]->iodev = iodev;
+ max77802_clks[i]->mask = MAX77802_CLOCK_OPMODE_MASK << i;
+ max77802_clks[i]->hw.init = &max77802_clks_init[i];
+
+ clocks[i] = max77802_clk_register(&pdev->dev, max77802_clks[i]);
+ if (IS_ERR(clocks[i])) {
+ ret = PTR_ERR(clocks[i]);
+ dev_err(&pdev->dev, "failed to register %s\n",
+ max77802_clks[i]->hw.init->name);
+ goto err_clocks;
+ }
+ }
+
+ /* 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");
+ goto err_clocks;
+ }
+
+ platform_set_drvdata(pdev, clocks);
+
+ if (iodev->dev->of_node) {
+ struct clk_onecell_data *of_data;
+
+ of_data = devm_kzalloc(&pdev->dev,
+ sizeof(*of_data), GFP_KERNEL);
+ if (!of_data) {
+ ret = -ENOMEM;
+ goto err_clocks;
+ }
+
+ of_data->clks = clocks;
+ of_data->clk_num = MAX77802_CLKS_NUM;
+ ret = of_clk_add_provider(iodev->dev->of_node,
+ of_clk_src_onecell_get, of_data);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register OF clock provider\n");
+ goto err_clocks;
+ }
+ }
+
+ return 0;
+
+err_clocks:
+ for (--i; i >= 0; --i) {
+ clkdev_drop(max77802_clks[i]->lookup);
+ clk_unregister(max77802_clks[i]->hw.clk);
+ }
+
+ return ret;
+}
+
+static int max77802_clk_remove(struct platform_device *pdev)
+{
+ struct max77802_dev *iodev = dev_get_drvdata(pdev->dev.parent);
+ struct clk **clocks = platform_get_drvdata(pdev);
+ int i;
+
+ if (iodev->dev->of_node)
+ of_clk_del_provider(iodev->dev->of_node);
+
+ for (i = 0; i < MAX77802_CLKS_NUM; i++) {
+ struct clk_hw *hw = __clk_get_hw(clocks[i]);
+ struct max77802_clk *max77802 = to_max77802_clk(hw);
+
+ clkdev_drop(max77802->lookup);
+ clk_unregister(clocks[i]);
+ }
+ return 0;
+}
+
+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,
+};
+
+static int __init max77802_clk_init(void)
+{
+ return platform_driver_register(&max77802_clk_driver);
+}
+subsys_initcall(max77802_clk_init);
+
+static void __init max77802_clk_cleanup(void)
+{
+ platform_driver_unregister(&max77802_clk_driver);
+}
+module_exit(max77802_clk_cleanup);
+
+MODULE_DESCRIPTION("MAXIM 77802 Clock Driver");
+MODULE_AUTHOR("Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/mfd/max77802.c b/drivers/mfd/max77802.c
index 59696dd..33e8023 100644
--- a/drivers/mfd/max77802.c
+++ b/drivers/mfd/max77802.c
@@ -35,6 +35,9 @@
static const struct mfd_cell max77802_devs[] = {
{ .name = "max77802-pmic", },
+#if defined(CONFIG_COMMON_CLK_MAX77802)
+ { .name = "max77802-clk", },
+#endif
};
static bool max77802_pmic_is_accessible_reg(struct device *dev,
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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/