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authorJonghwa Lee <jonghwa3.lee@samsung.com>2012-08-28 17:54:28 +0900
committerMike Turquette <mturquette@linaro.org>2012-09-06 16:55:38 -0700
commit73118e6188c23719eeec3560b7fd1ca76f1a0919 (patch)
tree9ba71716e05b80ea173383473cb18c4f1a14d776 /drivers/clk
parentebc96db7632f987e0b9bffcb782cf5cfb8afb0dd (diff)
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clock: max77686: Add driver for Maxim 77686 32Khz crystal oscillator.
This patch supports max77686 mfd's clock driver using common clock frame work. max77686 has 3 clock ouputs which all are generated from crystal oscillator and SOC can enable/disable them via I2C bus. All clocks are fixed-rate clock sources so that it doesn't supply interface for changing clock rate. Driver uses regmap API to communicate with internal register. Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com> Signed-off-by: Mike Turquette <mturquette@linaro.org>
Diffstat (limited to 'drivers/clk')
-rw-r--r--drivers/clk/Kconfig6
-rw-r--r--drivers/clk/Makefile1
-rw-r--r--drivers/clk/clk-max77686.c244
3 files changed, 251 insertions, 0 deletions
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index df33b8e2b5ad..bace9e98f75d 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -47,4 +47,10 @@ config COMMON_CLK_VERSATILE
Supports clocking on ARM Reference designs Integrator/AP,
Integrator/CP, RealView PB1176, EB, PB11MP and PBX.
+config COMMON_CLK_MAX77686
+ tristate "Clock driver for Maxim 77686 MFD"
+ depends on MFD_MAX77686
+ ---help---
+ This driver supports Maxim 77686 crystal oscillator clock.
+
endmenu
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index d561825a87fc..6327536b4900 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -19,3 +19,4 @@ obj-$(CONFIG_ARCH_U8500) += ux500/
# Chip specific
obj-$(CONFIG_COMMON_CLK_WM831X) += clk-wm831x.o
+obj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o
diff --git a/drivers/clk/clk-max77686.c b/drivers/clk/clk-max77686.c
new file mode 100644
index 000000000000..ac5f5434cb9a
--- /dev/null
+++ b/drivers/clk/clk-max77686.c
@@ -0,0 +1,244 @@
+/*
+ * clk-max77686.c - Clock driver for Maxim 77686
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/max77686.h>
+#include <linux/mfd/max77686-private.h>
+#include <linux/clk-provider.h>
+#include <linux/mutex.h>
+#include <linux/clkdev.h>
+
+enum {
+ MAX77686_CLK_AP = 0,
+ MAX77686_CLK_CP,
+ MAX77686_CLK_PMIC,
+ MAX77686_CLKS_NUM,
+};
+
+struct max77686_clk {
+ struct max77686_dev *iodev;
+ u32 mask;
+ struct clk_hw hw;
+ struct clk_lookup *lookup;
+};
+
+static struct max77686_clk *get_max77686_clk(struct clk_hw *hw)
+{
+ return container_of(hw, struct max77686_clk, hw);
+}
+
+static int max77686_clk_prepare(struct clk_hw *hw)
+{
+ struct max77686_clk *max77686;
+ int ret;
+
+ max77686 = get_max77686_clk(hw);
+ if (!max77686)
+ return -ENOMEM;
+
+ ret = regmap_update_bits(max77686->iodev->regmap,
+ MAX77686_REG_32KHZ, max77686->mask, max77686->mask);
+
+ return ret;
+}
+
+static void max77686_clk_unprepare(struct clk_hw *hw)
+{
+ struct max77686_clk *max77686;
+
+ max77686 = get_max77686_clk(hw);
+ if (!max77686)
+ return;
+
+ regmap_update_bits(max77686->iodev->regmap,
+ MAX77686_REG_32KHZ, max77686->mask, ~max77686->mask);
+}
+
+static int max77686_clk_is_enabled(struct clk_hw *hw)
+{
+ struct max77686_clk *max77686;
+ int ret;
+ u32 val;
+
+ max77686 = get_max77686_clk(hw);
+ if (!max77686)
+ return -ENOMEM;
+
+ ret = regmap_read(max77686->iodev->regmap,
+ MAX77686_REG_32KHZ, &val);
+
+ if (ret < 0)
+ return -EINVAL;
+
+ return val & max77686->mask;
+}
+
+static struct clk_ops max77686_clk_ops = {
+ .prepare = max77686_clk_prepare,
+ .unprepare = max77686_clk_unprepare,
+ .is_enabled = max77686_clk_is_enabled,
+};
+
+static struct clk_init_data max77686_clks_init[MAX77686_CLKS_NUM] = {
+ [MAX77686_CLK_AP] = {
+ .name = "32khz_ap",
+ .ops = &max77686_clk_ops,
+ .flags = CLK_IS_ROOT,
+ },
+ [MAX77686_CLK_CP] = {
+ .name = "32khz_cp",
+ .ops = &max77686_clk_ops,
+ .flags = CLK_IS_ROOT,
+ },
+ [MAX77686_CLK_PMIC] = {
+ .name = "32khz_pmic",
+ .ops = &max77686_clk_ops,
+ .flags = CLK_IS_ROOT,
+ },
+};
+
+static int max77686_clk_register(struct device *dev,
+ struct max77686_clk *max77686)
+{
+ struct clk *clk;
+ struct clk_hw *hw = &max77686->hw;
+
+ clk = clk_register(dev, hw);
+
+ if (IS_ERR(clk))
+ return -ENOMEM;
+
+ max77686->lookup = devm_kzalloc(dev, sizeof(struct clk_lookup),
+ GFP_KERNEL);
+ if (IS_ERR(max77686->lookup))
+ return -ENOMEM;
+
+ max77686->lookup->con_id = hw->init->name;
+ max77686->lookup->clk = clk;
+
+ clkdev_add(max77686->lookup);
+
+ return 0;
+}
+
+static __devinit int max77686_clk_probe(struct platform_device *pdev)
+{
+ struct max77686_dev *iodev = dev_get_drvdata(pdev->dev.parent);
+ struct max77686_clk **max77686_clks;
+ int i, ret;
+
+ max77686_clks = devm_kzalloc(&pdev->dev, sizeof(struct max77686_clk *)
+ * MAX77686_CLKS_NUM, GFP_KERNEL);
+ if (IS_ERR(max77686_clks))
+ return -ENOMEM;
+
+ for (i = 0; i < MAX77686_CLKS_NUM; i++) {
+ max77686_clks[i] = devm_kzalloc(&pdev->dev,
+ sizeof(struct max77686_clk), GFP_KERNEL);
+ if (IS_ERR(max77686_clks[i]))
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < MAX77686_CLKS_NUM; i++) {
+ max77686_clks[i]->iodev = iodev;
+ max77686_clks[i]->mask = 1 << i;
+ max77686_clks[i]->hw.init = &max77686_clks_init[i];
+
+ ret = max77686_clk_register(&pdev->dev, max77686_clks[i]);
+ if (ret) {
+ switch (i) {
+ case MAX77686_CLK_AP:
+ dev_err(&pdev->dev, "Fail to register CLK_AP\n");
+ goto err_clk_ap;
+ break;
+ case MAX77686_CLK_CP:
+ dev_err(&pdev->dev, "Fail to register CLK_CP\n");
+ goto err_clk_cp;
+ break;
+ case MAX77686_CLK_PMIC:
+ dev_err(&pdev->dev, "Fail to register CLK_PMIC\n");
+ goto err_clk_pmic;
+ }
+ }
+ }
+
+ platform_set_drvdata(pdev, max77686_clks);
+
+ goto out;
+
+err_clk_pmic:
+ clkdev_drop(max77686_clks[MAX77686_CLK_CP]->lookup);
+ kfree(max77686_clks[MAX77686_CLK_CP]->hw.clk);
+err_clk_cp:
+ clkdev_drop(max77686_clks[MAX77686_CLK_AP]->lookup);
+ kfree(max77686_clks[MAX77686_CLK_AP]->hw.clk);
+err_clk_ap:
+out:
+ return ret;
+}
+
+static int __devexit max77686_clk_remove(struct platform_device *pdev)
+{
+ struct max77686_clk **max77686_clks = platform_get_drvdata(pdev);
+ int i;
+
+ for (i = 0; i < MAX77686_CLKS_NUM; i++) {
+ clkdev_drop(max77686_clks[i]->lookup);
+ kfree(max77686_clks[i]->hw.clk);
+ }
+ return 0;
+}
+
+static const struct platform_device_id max77686_clk_id[] = {
+ { "max77686-clk", 0},
+ { },
+};
+MODULE_DEVICE_TABLE(platform, max77686_clk_id);
+
+static struct platform_driver max77686_clk_driver = {
+ .driver = {
+ .name = "max77686-clk",
+ .owner = THIS_MODULE,
+ },
+ .probe = max77686_clk_probe,
+ .remove = __devexit_p(max77686_clk_remove),
+ .id_table = max77686_clk_id,
+};
+
+static int __init max77686_clk_init(void)
+{
+ return platform_driver_register(&max77686_clk_driver);
+}
+subsys_initcall(max77686_clk_init);
+
+static void __init max77686_clk_cleanup(void)
+{
+ platform_driver_unregister(&max77686_clk_driver);
+}
+module_exit(max77686_clk_cleanup);
+
+MODULE_DESCRIPTION("MAXIM 77686 Clock Driver");
+MODULE_AUTHOR("Jonghwa Lee <jonghwa3.lee@samsung.com>");
+MODULE_LICENSE("GPL");