1 // SPDX-License-Identifier: GPL-2.0+ 2 // 3 // Driver for the IMX SNVS ON/OFF Power Key 4 // Copyright (C) 2015 Freescale Semiconductor, Inc. All Rights Reserved. 5 6 #include <linux/device.h> 7 #include <linux/err.h> 8 #include <linux/init.h> 9 #include <linux/input.h> 10 #include <linux/interrupt.h> 11 #include <linux/io.h> 12 #include <linux/jiffies.h> 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/of.h> 16 #include <linux/of_address.h> 17 #include <linux/platform_device.h> 18 #include <linux/pm_wakeirq.h> 19 #include <linux/mfd/syscon.h> 20 #include <linux/regmap.h> 21 22 #define SNVS_LPSR_REG 0x4C /* LP Status Register */ 23 #define SNVS_LPCR_REG 0x38 /* LP Control Register */ 24 #define SNVS_HPSR_REG 0x14 25 #define SNVS_HPSR_BTN BIT(6) 26 #define SNVS_LPSR_SPO BIT(18) 27 #define SNVS_LPCR_DEP_EN BIT(5) 28 29 #define DEBOUNCE_TIME 30 30 #define REPEAT_INTERVAL 60 31 32 struct pwrkey_drv_data { 33 struct regmap *snvs; 34 int irq; 35 int keycode; 36 int keystate; /* 1:pressed */ 37 int wakeup; 38 struct timer_list check_timer; 39 struct input_dev *input; 40 }; 41 42 static void imx_imx_snvs_check_for_events(struct timer_list *t) 43 { 44 struct pwrkey_drv_data *pdata = from_timer(pdata, t, check_timer); 45 struct input_dev *input = pdata->input; 46 u32 state; 47 48 regmap_read(pdata->snvs, SNVS_HPSR_REG, &state); 49 state = state & SNVS_HPSR_BTN ? 1 : 0; 50 51 /* only report new event if status changed */ 52 if (state ^ pdata->keystate) { 53 pdata->keystate = state; 54 input_event(input, EV_KEY, pdata->keycode, state); 55 input_sync(input); 56 pm_relax(pdata->input->dev.parent); 57 } 58 59 /* repeat check if pressed long */ 60 if (state) { 61 mod_timer(&pdata->check_timer, 62 jiffies + msecs_to_jiffies(REPEAT_INTERVAL)); 63 } 64 } 65 66 static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id) 67 { 68 struct platform_device *pdev = dev_id; 69 struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev); 70 u32 lp_status; 71 72 pm_wakeup_event(pdata->input->dev.parent, 0); 73 74 regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status); 75 if (lp_status & SNVS_LPSR_SPO) 76 mod_timer(&pdata->check_timer, jiffies + msecs_to_jiffies(DEBOUNCE_TIME)); 77 78 /* clear SPO status */ 79 regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO); 80 81 return IRQ_HANDLED; 82 } 83 84 static void imx_snvs_pwrkey_act(void *pdata) 85 { 86 struct pwrkey_drv_data *pd = pdata; 87 88 del_timer_sync(&pd->check_timer); 89 } 90 91 static int imx_snvs_pwrkey_probe(struct platform_device *pdev) 92 { 93 struct pwrkey_drv_data *pdata = NULL; 94 struct input_dev *input = NULL; 95 struct device_node *np; 96 int error; 97 98 /* Get SNVS register Page */ 99 np = pdev->dev.of_node; 100 if (!np) 101 return -ENODEV; 102 103 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); 104 if (!pdata) 105 return -ENOMEM; 106 107 pdata->snvs = syscon_regmap_lookup_by_phandle(np, "regmap"); 108 if (IS_ERR(pdata->snvs)) { 109 dev_err(&pdev->dev, "Can't get snvs syscon\n"); 110 return PTR_ERR(pdata->snvs); 111 } 112 113 if (of_property_read_u32(np, "linux,keycode", &pdata->keycode)) { 114 pdata->keycode = KEY_POWER; 115 dev_warn(&pdev->dev, "KEY_POWER without setting in dts\n"); 116 } 117 118 pdata->wakeup = of_property_read_bool(np, "wakeup-source"); 119 120 pdata->irq = platform_get_irq(pdev, 0); 121 if (pdata->irq < 0) 122 return -EINVAL; 123 124 regmap_update_bits(pdata->snvs, SNVS_LPCR_REG, SNVS_LPCR_DEP_EN, SNVS_LPCR_DEP_EN); 125 126 /* clear the unexpected interrupt before driver ready */ 127 regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO); 128 129 timer_setup(&pdata->check_timer, imx_imx_snvs_check_for_events, 0); 130 131 input = devm_input_allocate_device(&pdev->dev); 132 if (!input) { 133 dev_err(&pdev->dev, "failed to allocate the input device\n"); 134 return -ENOMEM; 135 } 136 137 input->name = pdev->name; 138 input->phys = "snvs-pwrkey/input0"; 139 input->id.bustype = BUS_HOST; 140 141 input_set_capability(input, EV_KEY, pdata->keycode); 142 143 /* input customer action to cancel release timer */ 144 error = devm_add_action(&pdev->dev, imx_snvs_pwrkey_act, pdata); 145 if (error) { 146 dev_err(&pdev->dev, "failed to register remove action\n"); 147 return error; 148 } 149 150 pdata->input = input; 151 platform_set_drvdata(pdev, pdata); 152 153 error = devm_request_irq(&pdev->dev, pdata->irq, 154 imx_snvs_pwrkey_interrupt, 155 0, pdev->name, pdev); 156 157 if (error) { 158 dev_err(&pdev->dev, "interrupt not available.\n"); 159 return error; 160 } 161 162 error = input_register_device(input); 163 if (error < 0) { 164 dev_err(&pdev->dev, "failed to register input device\n"); 165 return error; 166 } 167 168 device_init_wakeup(&pdev->dev, pdata->wakeup); 169 error = dev_pm_set_wake_irq(&pdev->dev, pdata->irq); 170 if (error) 171 dev_err(&pdev->dev, "irq wake enable failed.\n"); 172 173 return 0; 174 } 175 176 static const struct of_device_id imx_snvs_pwrkey_ids[] = { 177 { .compatible = "fsl,sec-v4.0-pwrkey" }, 178 { /* sentinel */ } 179 }; 180 MODULE_DEVICE_TABLE(of, imx_snvs_pwrkey_ids); 181 182 static struct platform_driver imx_snvs_pwrkey_driver = { 183 .driver = { 184 .name = "snvs_pwrkey", 185 .of_match_table = imx_snvs_pwrkey_ids, 186 }, 187 .probe = imx_snvs_pwrkey_probe, 188 }; 189 module_platform_driver(imx_snvs_pwrkey_driver); 190 191 MODULE_AUTHOR("Freescale Semiconductor"); 192 MODULE_DESCRIPTION("i.MX snvs power key Driver"); 193 MODULE_LICENSE("GPL"); 194