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 *get_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; 55 int ret; 56 57 max77686 = get_max77686_clk(hw); 58 if (!max77686) 59 return -ENOMEM; 60 61 ret = regmap_update_bits(max77686->iodev->regmap, 62 MAX77686_REG_32KHZ, max77686->mask, max77686->mask); 63 64 return ret; 65 } 66 67 static void max77686_clk_unprepare(struct clk_hw *hw) 68 { 69 struct max77686_clk *max77686; 70 71 max77686 = get_max77686_clk(hw); 72 if (!max77686) 73 return; 74 75 regmap_update_bits(max77686->iodev->regmap, 76 MAX77686_REG_32KHZ, max77686->mask, ~max77686->mask); 77 } 78 79 static int max77686_clk_is_enabled(struct clk_hw *hw) 80 { 81 struct max77686_clk *max77686; 82 int ret; 83 u32 val; 84 85 max77686 = get_max77686_clk(hw); 86 if (!max77686) 87 return -ENOMEM; 88 89 ret = regmap_read(max77686->iodev->regmap, 90 MAX77686_REG_32KHZ, &val); 91 92 if (ret < 0) 93 return -EINVAL; 94 95 return val & max77686->mask; 96 } 97 98 static struct clk_ops max77686_clk_ops = { 99 .prepare = max77686_clk_prepare, 100 .unprepare = max77686_clk_unprepare, 101 .is_enabled = max77686_clk_is_enabled, 102 }; 103 104 static struct clk_init_data max77686_clks_init[MAX77686_CLKS_NUM] = { 105 [MAX77686_CLK_AP] = { 106 .name = "32khz_ap", 107 .ops = &max77686_clk_ops, 108 .flags = CLK_IS_ROOT, 109 }, 110 [MAX77686_CLK_CP] = { 111 .name = "32khz_cp", 112 .ops = &max77686_clk_ops, 113 .flags = CLK_IS_ROOT, 114 }, 115 [MAX77686_CLK_PMIC] = { 116 .name = "32khz_pmic", 117 .ops = &max77686_clk_ops, 118 .flags = CLK_IS_ROOT, 119 }, 120 }; 121 122 static int max77686_clk_register(struct device *dev, 123 struct max77686_clk *max77686) 124 { 125 struct clk *clk; 126 struct clk_hw *hw = &max77686->hw; 127 128 clk = clk_register(dev, hw); 129 130 if (IS_ERR(clk)) 131 return -ENOMEM; 132 133 max77686->lookup = devm_kzalloc(dev, sizeof(struct clk_lookup), 134 GFP_KERNEL); 135 if (IS_ERR(max77686->lookup)) 136 return -ENOMEM; 137 138 max77686->lookup->con_id = hw->init->name; 139 max77686->lookup->clk = clk; 140 141 clkdev_add(max77686->lookup); 142 143 return 0; 144 } 145 146 static int max77686_clk_probe(struct platform_device *pdev) 147 { 148 struct max77686_dev *iodev = dev_get_drvdata(pdev->dev.parent); 149 struct max77686_clk **max77686_clks; 150 int i, ret; 151 152 max77686_clks = devm_kzalloc(&pdev->dev, sizeof(struct max77686_clk *) 153 * MAX77686_CLKS_NUM, GFP_KERNEL); 154 if (IS_ERR(max77686_clks)) 155 return -ENOMEM; 156 157 for (i = 0; i < MAX77686_CLKS_NUM; i++) { 158 max77686_clks[i] = devm_kzalloc(&pdev->dev, 159 sizeof(struct max77686_clk), GFP_KERNEL); 160 if (IS_ERR(max77686_clks[i])) 161 return -ENOMEM; 162 } 163 164 for (i = 0; i < MAX77686_CLKS_NUM; i++) { 165 max77686_clks[i]->iodev = iodev; 166 max77686_clks[i]->mask = 1 << i; 167 max77686_clks[i]->hw.init = &max77686_clks_init[i]; 168 169 ret = max77686_clk_register(&pdev->dev, max77686_clks[i]); 170 if (ret) { 171 switch (i) { 172 case MAX77686_CLK_AP: 173 dev_err(&pdev->dev, "Fail to register CLK_AP\n"); 174 goto err_clk_ap; 175 break; 176 case MAX77686_CLK_CP: 177 dev_err(&pdev->dev, "Fail to register CLK_CP\n"); 178 goto err_clk_cp; 179 break; 180 case MAX77686_CLK_PMIC: 181 dev_err(&pdev->dev, "Fail to register CLK_PMIC\n"); 182 goto err_clk_pmic; 183 } 184 } 185 } 186 187 platform_set_drvdata(pdev, max77686_clks); 188 189 goto out; 190 191 err_clk_pmic: 192 clkdev_drop(max77686_clks[MAX77686_CLK_CP]->lookup); 193 kfree(max77686_clks[MAX77686_CLK_CP]->hw.clk); 194 err_clk_cp: 195 clkdev_drop(max77686_clks[MAX77686_CLK_AP]->lookup); 196 kfree(max77686_clks[MAX77686_CLK_AP]->hw.clk); 197 err_clk_ap: 198 out: 199 return ret; 200 } 201 202 static int max77686_clk_remove(struct platform_device *pdev) 203 { 204 struct max77686_clk **max77686_clks = platform_get_drvdata(pdev); 205 int i; 206 207 for (i = 0; i < MAX77686_CLKS_NUM; i++) { 208 clkdev_drop(max77686_clks[i]->lookup); 209 kfree(max77686_clks[i]->hw.clk); 210 } 211 return 0; 212 } 213 214 static const struct platform_device_id max77686_clk_id[] = { 215 { "max77686-clk", 0}, 216 { }, 217 }; 218 MODULE_DEVICE_TABLE(platform, max77686_clk_id); 219 220 static struct platform_driver max77686_clk_driver = { 221 .driver = { 222 .name = "max77686-clk", 223 .owner = THIS_MODULE, 224 }, 225 .probe = max77686_clk_probe, 226 .remove = max77686_clk_remove, 227 .id_table = max77686_clk_id, 228 }; 229 230 static int __init max77686_clk_init(void) 231 { 232 return platform_driver_register(&max77686_clk_driver); 233 } 234 subsys_initcall(max77686_clk_init); 235 236 static void __init max77686_clk_cleanup(void) 237 { 238 platform_driver_unregister(&max77686_clk_driver); 239 } 240 module_exit(max77686_clk_cleanup); 241 242 MODULE_DESCRIPTION("MAXIM 77686 Clock Driver"); 243 MODULE_AUTHOR("Jonghwa Lee <jonghwa3.lee@samsung.com>"); 244 MODULE_LICENSE("GPL"); 245