1 /* 2 * clk-max77686.c - Clock driver for Maxim 77686 3 * 4 * Copyright (C) 2012 Samsung Electornics 5 * Jonghwa Lee <jonghwa3.lee@samsung.com> 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms of the GNU General Public License as published by the 9 * Free Software Foundation; either version 2 of the License, or (at your 10 * option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 * 21 */ 22 23 #include <linux/kernel.h> 24 #include <linux/slab.h> 25 #include <linux/err.h> 26 #include <linux/platform_device.h> 27 #include <linux/mfd/max77686.h> 28 #include <linux/mfd/max77686-private.h> 29 #include <linux/clk-provider.h> 30 #include <linux/mutex.h> 31 #include <linux/clkdev.h> 32 33 enum { 34 MAX77686_CLK_AP = 0, 35 MAX77686_CLK_CP, 36 MAX77686_CLK_PMIC, 37 MAX77686_CLKS_NUM, 38 }; 39 40 struct max77686_clk { 41 struct max77686_dev *iodev; 42 u32 mask; 43 struct clk_hw hw; 44 struct clk_lookup *lookup; 45 }; 46 47 static struct max77686_clk *to_max77686_clk(struct clk_hw *hw) 48 { 49 return container_of(hw, struct max77686_clk, hw); 50 } 51 52 static int max77686_clk_prepare(struct clk_hw *hw) 53 { 54 struct max77686_clk *max77686 = to_max77686_clk(hw); 55 56 return regmap_update_bits(max77686->iodev->regmap, 57 MAX77686_REG_32KHZ, max77686->mask, 58 max77686->mask); 59 } 60 61 static void max77686_clk_unprepare(struct clk_hw *hw) 62 { 63 struct max77686_clk *max77686 = to_max77686_clk(hw); 64 65 regmap_update_bits(max77686->iodev->regmap, 66 MAX77686_REG_32KHZ, max77686->mask, ~max77686->mask); 67 } 68 69 static int max77686_clk_is_enabled(struct clk_hw *hw) 70 { 71 struct max77686_clk *max77686 = to_max77686_clk(hw); 72 int ret; 73 u32 val; 74 75 ret = regmap_read(max77686->iodev->regmap, 76 MAX77686_REG_32KHZ, &val); 77 78 if (ret < 0) 79 return -EINVAL; 80 81 return val & max77686->mask; 82 } 83 84 static struct clk_ops max77686_clk_ops = { 85 .prepare = max77686_clk_prepare, 86 .unprepare = max77686_clk_unprepare, 87 .is_enabled = max77686_clk_is_enabled, 88 }; 89 90 static struct clk_init_data max77686_clks_init[MAX77686_CLKS_NUM] = { 91 [MAX77686_CLK_AP] = { 92 .name = "32khz_ap", 93 .ops = &max77686_clk_ops, 94 .flags = CLK_IS_ROOT, 95 }, 96 [MAX77686_CLK_CP] = { 97 .name = "32khz_cp", 98 .ops = &max77686_clk_ops, 99 .flags = CLK_IS_ROOT, 100 }, 101 [MAX77686_CLK_PMIC] = { 102 .name = "32khz_pmic", 103 .ops = &max77686_clk_ops, 104 .flags = CLK_IS_ROOT, 105 }, 106 }; 107 108 static int max77686_clk_register(struct device *dev, 109 struct max77686_clk *max77686) 110 { 111 struct clk *clk; 112 struct clk_hw *hw = &max77686->hw; 113 114 clk = clk_register(dev, hw); 115 116 if (IS_ERR(clk)) 117 return -ENOMEM; 118 119 max77686->lookup = kzalloc(sizeof(struct clk_lookup), GFP_KERNEL); 120 if (!max77686->lookup) 121 return -ENOMEM; 122 123 max77686->lookup->con_id = hw->init->name; 124 max77686->lookup->clk = clk; 125 126 clkdev_add(max77686->lookup); 127 128 return 0; 129 } 130 131 static int max77686_clk_probe(struct platform_device *pdev) 132 { 133 struct max77686_dev *iodev = dev_get_drvdata(pdev->dev.parent); 134 struct max77686_clk **max77686_clks; 135 int i, ret; 136 137 max77686_clks = devm_kzalloc(&pdev->dev, sizeof(struct max77686_clk *) 138 * MAX77686_CLKS_NUM, GFP_KERNEL); 139 if (!max77686_clks) 140 return -ENOMEM; 141 142 for (i = 0; i < MAX77686_CLKS_NUM; i++) { 143 max77686_clks[i] = devm_kzalloc(&pdev->dev, 144 sizeof(struct max77686_clk), GFP_KERNEL); 145 if (!max77686_clks[i]) 146 return -ENOMEM; 147 } 148 149 for (i = 0; i < MAX77686_CLKS_NUM; i++) { 150 max77686_clks[i]->iodev = iodev; 151 max77686_clks[i]->mask = 1 << i; 152 max77686_clks[i]->hw.init = &max77686_clks_init[i]; 153 154 ret = max77686_clk_register(&pdev->dev, max77686_clks[i]); 155 if (ret) { 156 switch (i) { 157 case MAX77686_CLK_AP: 158 dev_err(&pdev->dev, "Fail to register CLK_AP\n"); 159 goto err_clk_ap; 160 break; 161 case MAX77686_CLK_CP: 162 dev_err(&pdev->dev, "Fail to register CLK_CP\n"); 163 goto err_clk_cp; 164 break; 165 case MAX77686_CLK_PMIC: 166 dev_err(&pdev->dev, "Fail to register CLK_PMIC\n"); 167 goto err_clk_pmic; 168 } 169 } 170 } 171 172 platform_set_drvdata(pdev, max77686_clks); 173 174 goto out; 175 176 err_clk_pmic: 177 clkdev_drop(max77686_clks[MAX77686_CLK_CP]->lookup); 178 kfree(max77686_clks[MAX77686_CLK_CP]->hw.clk); 179 err_clk_cp: 180 clkdev_drop(max77686_clks[MAX77686_CLK_AP]->lookup); 181 kfree(max77686_clks[MAX77686_CLK_AP]->hw.clk); 182 err_clk_ap: 183 out: 184 return ret; 185 } 186 187 static int max77686_clk_remove(struct platform_device *pdev) 188 { 189 struct max77686_clk **max77686_clks = platform_get_drvdata(pdev); 190 int i; 191 192 for (i = 0; i < MAX77686_CLKS_NUM; i++) { 193 clkdev_drop(max77686_clks[i]->lookup); 194 kfree(max77686_clks[i]->hw.clk); 195 } 196 return 0; 197 } 198 199 static const struct platform_device_id max77686_clk_id[] = { 200 { "max77686-clk", 0}, 201 { }, 202 }; 203 MODULE_DEVICE_TABLE(platform, max77686_clk_id); 204 205 static struct platform_driver max77686_clk_driver = { 206 .driver = { 207 .name = "max77686-clk", 208 .owner = THIS_MODULE, 209 }, 210 .probe = max77686_clk_probe, 211 .remove = max77686_clk_remove, 212 .id_table = max77686_clk_id, 213 }; 214 215 static int __init max77686_clk_init(void) 216 { 217 return platform_driver_register(&max77686_clk_driver); 218 } 219 subsys_initcall(max77686_clk_init); 220 221 static void __init max77686_clk_cleanup(void) 222 { 223 platform_driver_unregister(&max77686_clk_driver); 224 } 225 module_exit(max77686_clk_cleanup); 226 227 MODULE_DESCRIPTION("MAXIM 77686 Clock Driver"); 228 MODULE_AUTHOR("Jonghwa Lee <jonghwa3.lee@samsung.com>"); 229 MODULE_LICENSE("GPL"); 230