input/keyboard/snvs_pwrkey.c

0001 // SPDX-License-Identifier: GPL-2.0+
0002 //
0003 // Driver for the IMX SNVS ON/OFF Power Key
0004 // Copyright (C) 2015 Freescale Semiconductor, Inc. All Rights Reserved.
0005
0006 #include <linux/clk.h>
0007 #include <linux/device.h>
0008 #include <linux/err.h>
0009 #include <linux/init.h>
0010 #include <linux/input.h>
0011 #include <linux/interrupt.h>
0012 #include <linux/io.h>
0013 #include <linux/jiffies.h>
0014 #include <linux/kernel.h>
0015 #include <linux/module.h>
0016 #include <linux/of.h>
0017 #include <linux/of_address.h>
0018 #include <linux/platform_device.h>
0019 #include <linux/pm_wakeirq.h>
0020 #include <linux/mfd/syscon.h>
0021 #include <linux/regmap.h>
0022
0023 #define SNVS_HPVIDR1_REG    0xBF8
0024 #define SNVS_LPSR_REG       0x4C    /* LP Status Register */
0025 #define SNVS_LPCR_REG       0x38    /* LP Control Register */
0026 #define SNVS_HPSR_REG       0x14
0027 #define SNVS_HPSR_BTN       BIT(6)
0028 #define SNVS_LPSR_SPO       BIT(18)
0029 #define SNVS_LPCR_DEP_EN    BIT(5)
0030
0031 #define DEBOUNCE_TIME       30
0032 #define REPEAT_INTERVAL     60
0033
0034 struct pwrkey_drv_data {
0035     struct regmap *snvs;
0036     int irq;
0037     int keycode;
0038     int keystate;  /* 1:pressed */
0039     int wakeup;
0040     struct timer_list check_timer;
0041     struct input_dev *input;
0042     u8 minor_rev;
0043 };
0044
0045 static void imx_imx_snvs_check_for_events(struct timer_list *t)
0046 {
0047     struct pwrkey_drv_data *pdata = from_timer(pdata, t, check_timer);
0048     struct input_dev *input = pdata->input;
0049     u32 state;
0050
0051     regmap_read(pdata->snvs, SNVS_HPSR_REG, &state);
0052     state = state & SNVS_HPSR_BTN ? 1 : 0;
0053
0054     /* only report new event if status changed */
0055     if (state ^ pdata->keystate) {
0056         pdata->keystate = state;
0057         input_event(input, EV_KEY, pdata->keycode, state);
0058         input_sync(input);
0059         pm_relax(pdata->input->dev.parent);
0060     }
0061
0062     /* repeat check if pressed long */
0063     if (state) {
0064         mod_timer(&pdata->check_timer,
0065               jiffies + msecs_to_jiffies(REPEAT_INTERVAL));
0066     }
0067 }
0068
0069 static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
0070 {
0071     struct platform_device *pdev = dev_id;
0072     struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
0073     struct input_dev *input = pdata->input;
0074     u32 lp_status;
0075
0076     pm_wakeup_event(input->dev.parent, 0);
0077
0078     regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status);
0079     if (lp_status & SNVS_LPSR_SPO) {
0080         if (pdata->minor_rev == 0) {
0081             /*
0082              * The first generation i.MX6 SoCs only sends an
0083              * interrupt on button release. To mimic power-key
0084              * usage, we'll prepend a press event.
0085              */
0086             input_report_key(input, pdata->keycode, 1);
0087             input_sync(input);
0088             input_report_key(input, pdata->keycode, 0);
0089             input_sync(input);
0090             pm_relax(input->dev.parent);
0091         } else {
0092             mod_timer(&pdata->check_timer,
0093                       jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
0094         }
0095     }
0096
0097     /* clear SPO status */
0098     regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
0099
0100     return IRQ_HANDLED;
0101 }
0102
0103 static void imx_snvs_pwrkey_disable_clk(void *data)
0104 {
0105     clk_disable_unprepare(data);
0106 }
0107
0108 static void imx_snvs_pwrkey_act(void *pdata)
0109 {
0110     struct pwrkey_drv_data *pd = pdata;
0111
0112     del_timer_sync(&pd->check_timer);
0113 }
0114
0115 static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
0116 {
0117     struct pwrkey_drv_data *pdata;
0118     struct input_dev *input;
0119     struct device_node *np;
0120     struct clk *clk;
0121     int error;
0122     u32 vid;
0123
0124     /* Get SNVS register Page */
0125     np = pdev->dev.of_node;
0126     if (!np)
0127         return -ENODEV;
0128
0129     pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
0130     if (!pdata)
0131         return -ENOMEM;
0132
0133     pdata->snvs = syscon_regmap_lookup_by_phandle(np, "regmap");
0134     if (IS_ERR(pdata->snvs)) {
0135         dev_err(&pdev->dev, "Can't get snvs syscon\n");
0136         return PTR_ERR(pdata->snvs);
0137     }
0138
0139     if (of_property_read_u32(np, "linux,keycode", &pdata->keycode)) {
0140         pdata->keycode = KEY_POWER;
0141         dev_warn(&pdev->dev, "KEY_POWER without setting in dts\n");
0142     }
0143
0144     clk = devm_clk_get_optional(&pdev->dev, NULL);
0145     if (IS_ERR(clk)) {
0146         dev_err(&pdev->dev, "Failed to get snvs clock (%pe)\n", clk);
0147         return PTR_ERR(clk);
0148     }
0149
0150     error = clk_prepare_enable(clk);
0151     if (error) {
0152         dev_err(&pdev->dev, "Failed to enable snvs clock (%pe)\n",
0153             ERR_PTR(error));
0154         return error;
0155     }
0156
0157     error = devm_add_action_or_reset(&pdev->dev,
0158                      imx_snvs_pwrkey_disable_clk, clk);
0159     if (error) {
0160         dev_err(&pdev->dev,
0161             "Failed to register clock cleanup handler (%pe)\n",
0162             ERR_PTR(error));
0163         return error;
0164     }
0165
0166     pdata->wakeup = of_property_read_bool(np, "wakeup-source");
0167
0168     pdata->irq = platform_get_irq(pdev, 0);
0169     if (pdata->irq < 0)
0170         return -EINVAL;
0171
0172     regmap_read(pdata->snvs, SNVS_HPVIDR1_REG, &vid);
0173     pdata->minor_rev = vid & 0xff;
0174
0175     regmap_update_bits(pdata->snvs, SNVS_LPCR_REG, SNVS_LPCR_DEP_EN, SNVS_LPCR_DEP_EN);
0176
0177     /* clear the unexpected interrupt before driver ready */
0178     regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
0179
0180     timer_setup(&pdata->check_timer, imx_imx_snvs_check_for_events, 0);
0181
0182     input = devm_input_allocate_device(&pdev->dev);
0183     if (!input) {
0184         dev_err(&pdev->dev, "failed to allocate the input device\n");
0185         return -ENOMEM;
0186     }
0187
0188     input->name = pdev->name;
0189     input->phys = "snvs-pwrkey/input0";
0190     input->id.bustype = BUS_HOST;
0191
0192     input_set_capability(input, EV_KEY, pdata->keycode);
0193
0194     /* input customer action to cancel release timer */
0195     error = devm_add_action(&pdev->dev, imx_snvs_pwrkey_act, pdata);
0196     if (error) {
0197         dev_err(&pdev->dev, "failed to register remove action\n");
0198         return error;
0199     }
0200
0201     pdata->input = input;
0202     platform_set_drvdata(pdev, pdata);
0203
0204     error = devm_request_irq(&pdev->dev, pdata->irq,
0205                    imx_snvs_pwrkey_interrupt,
0206                    0, pdev->name, pdev);
0207
0208     if (error) {
0209         dev_err(&pdev->dev, "interrupt not available.\n");
0210         return error;
0211     }
0212
0213     error = input_register_device(input);
0214     if (error < 0) {
0215         dev_err(&pdev->dev, "failed to register input device\n");
0216         return error;
0217     }
0218
0219     device_init_wakeup(&pdev->dev, pdata->wakeup);
0220     error = dev_pm_set_wake_irq(&pdev->dev, pdata->irq);
0221     if (error)
0222         dev_err(&pdev->dev, "irq wake enable failed.\n");
0223
0224     return 0;
0225 }
0226
0227 static const struct of_device_id imx_snvs_pwrkey_ids[] = {
0228     { .compatible = "fsl,sec-v4.0-pwrkey" },
0229     { /* sentinel */ }
0230 };
0231 MODULE_DEVICE_TABLE(of, imx_snvs_pwrkey_ids);
0232
0233 static struct platform_driver imx_snvs_pwrkey_driver = {
0234     .driver = {
0235         .name = "snvs_pwrkey",
0236         .of_match_table = imx_snvs_pwrkey_ids,
0237     },
0238     .probe = imx_snvs_pwrkey_probe,
0239 };
0240 module_platform_driver(imx_snvs_pwrkey_driver);
0241
0242 MODULE_AUTHOR("Freescale Semiconductor");
0243 MODULE_DESCRIPTION("i.MX snvs power key Driver");
0244 MODULE_LICENSE("GPL");