Re: [PATCH] clock: max77686: Add driver for Maxim 77686 32Khz crystaloscillator.

From: Mike Turquette
Date: Thu Sep 06 2012 - 20:04:19 EST


Quoting Jonghwa Lee (2012-08-28 01:54:28)
> 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@xxxxxxxxxxx>

Looks good. I've taken this into clk-next.

Regards,
Mike

> ---
> v5
> - Add registering failure handle for each clocks to prevent memory leak.
> - Update to use the latest clk_register. (Add clk_init_data).
> - Rename Kconfig menu's name and replace its position.
>
> v4
> https://lkml.org/lkml/2012/6/27/183
>
> drivers/clk/Kconfig | 6 +
> drivers/clk/Makefile | 1 +
> drivers/clk/clk-max77686.c | 244 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 251 insertions(+), 0 deletions(-)
> create mode 100644 drivers/clk/clk-max77686.c
>
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index 7f0b5ca..f300ec7 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -40,4 +40,10 @@ config COMMON_CLK_WM831X
> Supports the clocking subsystem of the WM831x/2x series of
> PMICs from Wolfson Microlectronics.
>
> +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 5869ea3..97f5c57 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -13,3 +13,4 @@ obj-$(CONFIG_ARCH_INTEGRATOR) += versatile/
>
> # Chip specific
> obj-$(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 0000000..ac5f543
> --- /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@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.
> + *
> + * 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@xxxxxxxxxxx>");
> +MODULE_LICENSE("GPL");
> --
> 1.7.4.1
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