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 void 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 93 #ifdef CONFIG_PM 94 static int fimc_is_i2c_runtime_suspend(struct device *dev) 95 { 96 struct fimc_is_i2c *isp_i2c = dev_get_drvdata(dev); 97 98 clk_disable_unprepare(isp_i2c->clock); 99 return 0; 100 } 101 102 static int fimc_is_i2c_runtime_resume(struct device *dev) 103 { 104 struct fimc_is_i2c *isp_i2c = dev_get_drvdata(dev); 105 106 return clk_prepare_enable(isp_i2c->clock); 107 } 108 #endif 109 110 #ifdef CONFIG_PM_SLEEP 111 static int fimc_is_i2c_suspend(struct device *dev) 112 { 113 if (pm_runtime_suspended(dev)) 114 return 0; 115 116 return fimc_is_i2c_runtime_suspend(dev); 117 } 118 119 static int fimc_is_i2c_resume(struct device *dev) 120 { 121 if (pm_runtime_suspended(dev)) 122 return 0; 123 124 return fimc_is_i2c_runtime_resume(dev); 125 } 126 #endif 127 128 static const struct dev_pm_ops fimc_is_i2c_pm_ops = { 129 SET_RUNTIME_PM_OPS(fimc_is_i2c_runtime_suspend, 130 fimc_is_i2c_runtime_resume, NULL) 131 SET_SYSTEM_SLEEP_PM_OPS(fimc_is_i2c_suspend, fimc_is_i2c_resume) 132 }; 133 134 static const struct of_device_id fimc_is_i2c_of_match[] = { 135 { .compatible = FIMC_IS_I2C_COMPATIBLE }, 136 { }, 137 }; 138 139 static struct platform_driver fimc_is_i2c_driver = { 140 .probe = fimc_is_i2c_probe, 141 .remove_new = fimc_is_i2c_remove, 142 .driver = { 143 .of_match_table = fimc_is_i2c_of_match, 144 .name = "fimc-isp-i2c", 145 .pm = &fimc_is_i2c_pm_ops, 146 } 147 }; 148 149 int fimc_is_register_i2c_driver(void) 150 { 151 return platform_driver_register(&fimc_is_i2c_driver); 152 } 153 154 void fimc_is_unregister_i2c_driver(void) 155 { 156 platform_driver_unregister(&fimc_is_i2c_driver); 157 } 158