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

[Mike Turquette <mturquette@linaro.org>]

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@samsung.com>

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@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");
> -- 
> 1.7.4.1