1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Samsung EXYNOS4x12 FIMC-IS (Imaging Subsystem) driver 4 * 5 * Copyright (C) 2013 Samsung Electronics Co., Ltd. 6 * 7 * Author: Sylwester Nawrocki <s.nawrocki@samsung.com> 8 */ 9 10 #include <linux/clk.h> 11 #include <linux/module.h> 12 #include <linux/i2c.h> 13 #include <linux/platform_device.h> 14 #include <linux/pm_runtime.h> 15 #include <linux/slab.h> 16 #include "fimc-is-i2c.h" 17 18 struct fimc_is_i2c { 19 struct i2c_adapter adapter; 20 struct clk *clock; 21 }; 22 23 /* 24 * An empty algorithm is used as the actual I2C bus controller driver 25 * is implemented in the FIMC-IS subsystem firmware and the host CPU 26 * doesn't access the I2C bus controller. 27 */ 28 static u32 is_i2c_func(struct i2c_adapter *adap) 29 { 30 return I2C_FUNC_I2C; 31 } 32 33 static const struct i2c_algorithm fimc_is_i2c_algorithm = { 34 .functionality = is_i2c_func, 35 }; 36 37 static int fimc_is_i2c_probe(struct platform_device *pdev) 38 { 39 struct device_node *node = pdev->dev.of_node; 40 struct fimc_is_i2c *isp_i2c; 41 struct i2c_adapter *i2c_adap; 42 int ret; 43 44 isp_i2c = devm_kzalloc(&pdev->dev, sizeof(*isp_i2c), GFP_KERNEL); 45 if (!isp_i2c) 46 return -ENOMEM; 47 48 isp_i2c->clock = devm_clk_get(&pdev->dev, "i2c_isp"); 49 if (IS_ERR(isp_i2c->clock)) { 50 dev_err(&pdev->dev, "failed to get the clock\n"); 51 return PTR_ERR(isp_i2c->clock); 52 } 53 54 i2c_adap = &isp_i2c->adapter; 55 i2c_adap->dev.of_node = node; 56 i2c_adap->dev.parent = &pdev->dev; 57 strscpy(i2c_adap->name, "exynos4x12-isp-i2c", sizeof(i2c_adap->name)); 58 i2c_adap->owner = THIS_MODULE; 59 i2c_adap->algo = &fimc_is_i2c_algorithm; 60 i2c_adap->class = I2C_CLASS_SPD; 61 62 platform_set_drvdata(pdev, isp_i2c); 63 pm_runtime_enable(&pdev->dev); 64 65 ret = i2c_add_adapter(i2c_adap); 66 if (ret < 0) 67 goto err_pm_dis; 68 /* 69 * Client drivers of this adapter don't do any I2C transfers as that 70 * is handled by the ISP firmware. But we rely on the runtime PM 71 * state propagation from the clients up to the adapter driver so 72 * clear the ignore_children flags here. PM rutnime calls are not 73 * used in probe() handler of clients of this adapter so there is 74 * no issues with clearing the flag right after registering the I2C 75 * adapter. 76 */ 77 pm_suspend_ignore_children(&i2c_adap->dev, false); 78 return 0; 79 80 err_pm_dis: 81 pm_runtime_disable(&pdev->dev); 82 return ret; 83 } 84 85 static int fimc_is_i2c_remove(struct platform_device *pdev) 86 { 87 struct fimc_is_i2c *isp_i2c = platform_get_drvdata(pdev); 88 89 pm_runtime_disable(&pdev->dev); 90 i2c_del_adapter(&isp_i2c->adapter); 91 92 return 0; 93 } 94 95 #ifdef CONFIG_PM 96 static int fimc_is_i2c_runtime_suspend(struct device *dev) 97 { 98 struct fimc_is_i2c *isp_i2c = dev_get_drvdata(dev); 99 100 clk_disable_unprepare(isp_i2c->clock); 101 return 0; 102 } 103 104 static int fimc_is_i2c_runtime_resume(struct device *dev) 105 { 106 struct fimc_is_i2c *isp_i2c = dev_get_drvdata(dev); 107 108 return clk_prepare_enable(isp_i2c->clock); 109 } 110 #endif 111 112 #ifdef CONFIG_PM_SLEEP 113 static int fimc_is_i2c_suspend(struct device *dev) 114 { 115 if (pm_runtime_suspended(dev)) 116 return 0; 117 118 return fimc_is_i2c_runtime_suspend(dev); 119 } 120 121 static int fimc_is_i2c_resume(struct device *dev) 122 { 123 if (pm_runtime_suspended(dev)) 124 return 0; 125 126 return fimc_is_i2c_runtime_resume(dev); 127 } 128 #endif 129 130 static const struct dev_pm_ops fimc_is_i2c_pm_ops = { 131 SET_RUNTIME_PM_OPS(fimc_is_i2c_runtime_suspend, 132 fimc_is_i2c_runtime_resume, NULL) 133 SET_SYSTEM_SLEEP_PM_OPS(fimc_is_i2c_suspend, fimc_is_i2c_resume) 134 }; 135 136 static const struct of_device_id fimc_is_i2c_of_match[] = { 137 { .compatible = FIMC_IS_I2C_COMPATIBLE }, 138 { }, 139 }; 140 141 static struct platform_driver fimc_is_i2c_driver = { 142 .probe = fimc_is_i2c_probe, 143 .remove = fimc_is_i2c_remove, 144 .driver = { 145 .of_match_table = fimc_is_i2c_of_match, 146 .name = "fimc-isp-i2c", 147 .pm = &fimc_is_i2c_pm_ops, 148 } 149 }; 150 151 int fimc_is_register_i2c_driver(void) 152 { 153 return platform_driver_register(&fimc_is_i2c_driver); 154 } 155 156 void fimc_is_unregister_i2c_driver(void) 157 { 158 platform_driver_unregister(&fimc_is_i2c_driver); 159 } 160