From: Jonghwa Lee Date: Tue, 28 Aug 2012 08:54:28 +0000 (+0900) Subject: clock: max77686: Add driver for Maxim 77686 32Khz crystal oscillator. X-Git-Tag: next-20120910~3^2~5 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=73118e6188c23719eeec3560b7fd1ca76f1a0919;p=karo-tx-linux.git 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 Signed-off-by: Mike Turquette --- 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 + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include + +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 "); +MODULE_LICENSE("GPL");