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| 1 | +// SPDX-License-Identifier: GPL-2.0-or-later |
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1 | 2 | /* |
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2 | 3 | * pps-gpio.c -- PPS client driver using GPIO |
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3 | 4 | * |
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4 | | - * |
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5 | 5 | * Copyright (C) 2010 Ricardo Martins <rasm@fe.up.pt> |
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6 | 6 | * Copyright (C) 2011 James Nuss <jamesnuss@nanometrics.ca> |
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7 | | - * |
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8 | | - * This program is free software; you can redistribute it and/or modify |
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9 | | - * it under the terms of the GNU General Public License as published by |
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10 | | - * the Free Software Foundation; either version 2 of the License, or |
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11 | | - * (at your option) any later version. |
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12 | | - * |
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13 | | - * This program is distributed in the hope that it will be useful, |
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14 | | - * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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15 | | - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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16 | | - * GNU General Public License for more details. |
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17 | | - * |
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18 | | - * You should have received a copy of the GNU General Public License |
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19 | | - * along with this program; if not, write to the Free Software |
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20 | | - * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
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21 | 7 | */ |
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22 | 8 | |
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23 | 9 | #define PPS_GPIO_NAME "pps-gpio" |
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.. | .. |
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31 | 17 | #include <linux/slab.h> |
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32 | 18 | #include <linux/pps_kernel.h> |
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33 | 19 | #include <linux/pps-gpio.h> |
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34 | | -#include <linux/gpio.h> |
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| 20 | +#include <linux/gpio/consumer.h> |
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35 | 21 | #include <linux/list.h> |
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36 | 22 | #include <linux/of_device.h> |
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37 | 23 | #include <linux/of_gpio.h> |
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| 24 | +#include <linux/timer.h> |
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| 25 | +#include <linux/jiffies.h> |
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38 | 26 | |
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39 | 27 | /* Info for each registered platform device */ |
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40 | 28 | struct pps_gpio_device_data { |
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41 | 29 | int irq; /* IRQ used as PPS source */ |
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42 | 30 | struct pps_device *pps; /* PPS source device */ |
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43 | 31 | struct pps_source_info info; /* PPS source information */ |
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| 32 | + struct gpio_desc *gpio_pin; /* GPIO port descriptors */ |
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| 33 | + struct gpio_desc *echo_pin; |
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| 34 | + struct timer_list echo_timer; /* timer to reset echo active state */ |
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44 | 35 | bool assert_falling_edge; |
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45 | 36 | bool capture_clear; |
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46 | | - unsigned int gpio_pin; |
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| 37 | + unsigned int echo_active_ms; /* PPS echo active duration */ |
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| 38 | + unsigned long echo_timeout; /* timer timeout value in jiffies */ |
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47 | 39 | }; |
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48 | 40 | |
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49 | 41 | /* |
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.. | .. |
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61 | 53 | |
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62 | 54 | info = data; |
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63 | 55 | |
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64 | | - rising_edge = gpio_get_value(info->gpio_pin); |
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| 56 | + rising_edge = gpiod_get_value(info->gpio_pin); |
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65 | 57 | if ((rising_edge && !info->assert_falling_edge) || |
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66 | 58 | (!rising_edge && info->assert_falling_edge)) |
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67 | | - pps_event(info->pps, &ts, PPS_CAPTUREASSERT, NULL); |
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| 59 | + pps_event(info->pps, &ts, PPS_CAPTUREASSERT, data); |
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68 | 60 | else if (info->capture_clear && |
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69 | 61 | ((rising_edge && info->assert_falling_edge) || |
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70 | | - (!rising_edge && !info->assert_falling_edge))) |
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71 | | - pps_event(info->pps, &ts, PPS_CAPTURECLEAR, NULL); |
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| 62 | + (!rising_edge && !info->assert_falling_edge))) |
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| 63 | + pps_event(info->pps, &ts, PPS_CAPTURECLEAR, data); |
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72 | 64 | |
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73 | 65 | return IRQ_HANDLED; |
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| 66 | +} |
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| 67 | + |
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| 68 | +/* This function will only be called when an ECHO GPIO is defined */ |
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| 69 | +static void pps_gpio_echo(struct pps_device *pps, int event, void *data) |
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| 70 | +{ |
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| 71 | + /* add_timer() needs to write into info->echo_timer */ |
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| 72 | + struct pps_gpio_device_data *info = data; |
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| 73 | + |
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| 74 | + switch (event) { |
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| 75 | + case PPS_CAPTUREASSERT: |
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| 76 | + if (pps->params.mode & PPS_ECHOASSERT) |
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| 77 | + gpiod_set_value(info->echo_pin, 1); |
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| 78 | + break; |
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| 79 | + |
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| 80 | + case PPS_CAPTURECLEAR: |
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| 81 | + if (pps->params.mode & PPS_ECHOCLEAR) |
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| 82 | + gpiod_set_value(info->echo_pin, 1); |
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| 83 | + break; |
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| 84 | + } |
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| 85 | + |
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| 86 | + /* fire the timer */ |
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| 87 | + if (info->pps->params.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) { |
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| 88 | + info->echo_timer.expires = jiffies + info->echo_timeout; |
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| 89 | + add_timer(&info->echo_timer); |
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| 90 | + } |
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| 91 | +} |
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| 92 | + |
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| 93 | +/* Timer callback to reset the echo pin to the inactive state */ |
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| 94 | +static void pps_gpio_echo_timer_callback(struct timer_list *t) |
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| 95 | +{ |
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| 96 | + const struct pps_gpio_device_data *info; |
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| 97 | + |
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| 98 | + info = from_timer(info, t, echo_timer); |
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| 99 | + |
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| 100 | + gpiod_set_value(info->echo_pin, 0); |
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| 101 | +} |
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| 102 | + |
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| 103 | +static int pps_gpio_setup(struct platform_device *pdev) |
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| 104 | +{ |
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| 105 | + struct pps_gpio_device_data *data = platform_get_drvdata(pdev); |
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| 106 | + struct device_node *np = pdev->dev.of_node; |
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| 107 | + int ret; |
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| 108 | + u32 value; |
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| 109 | + |
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| 110 | + data->gpio_pin = devm_gpiod_get(&pdev->dev, |
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| 111 | + NULL, /* request "gpios" */ |
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| 112 | + GPIOD_IN); |
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| 113 | + if (IS_ERR(data->gpio_pin)) { |
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| 114 | + dev_err(&pdev->dev, |
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| 115 | + "failed to request PPS GPIO\n"); |
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| 116 | + return PTR_ERR(data->gpio_pin); |
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| 117 | + } |
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| 118 | + |
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| 119 | + data->echo_pin = devm_gpiod_get_optional(&pdev->dev, |
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| 120 | + "echo", |
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| 121 | + GPIOD_OUT_LOW); |
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| 122 | + if (data->echo_pin) { |
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| 123 | + if (IS_ERR(data->echo_pin)) { |
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| 124 | + dev_err(&pdev->dev, "failed to request ECHO GPIO\n"); |
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| 125 | + return PTR_ERR(data->echo_pin); |
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| 126 | + } |
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| 127 | + |
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| 128 | + ret = of_property_read_u32(np, |
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| 129 | + "echo-active-ms", |
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| 130 | + &value); |
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| 131 | + if (ret) { |
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| 132 | + dev_err(&pdev->dev, |
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| 133 | + "failed to get echo-active-ms from OF\n"); |
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| 134 | + return ret; |
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| 135 | + } |
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| 136 | + data->echo_active_ms = value; |
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| 137 | + /* sanity check on echo_active_ms */ |
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| 138 | + if (!data->echo_active_ms || data->echo_active_ms > 999) { |
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| 139 | + dev_err(&pdev->dev, |
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| 140 | + "echo-active-ms: %u - bad value from OF\n", |
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| 141 | + data->echo_active_ms); |
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| 142 | + return -EINVAL; |
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| 143 | + } |
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| 144 | + } |
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| 145 | + |
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| 146 | + if (of_property_read_bool(np, "assert-falling-edge")) |
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| 147 | + data->assert_falling_edge = true; |
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| 148 | + return 0; |
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74 | 149 | } |
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75 | 150 | |
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76 | 151 | static unsigned long |
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.. | .. |
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90 | 165 | static int pps_gpio_probe(struct platform_device *pdev) |
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91 | 166 | { |
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92 | 167 | struct pps_gpio_device_data *data; |
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93 | | - const char *gpio_label; |
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94 | 168 | int ret; |
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95 | 169 | int pps_default_params; |
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96 | 170 | const struct pps_gpio_platform_data *pdata = pdev->dev.platform_data; |
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97 | | - struct device_node *np = pdev->dev.of_node; |
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98 | 171 | |
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99 | 172 | /* allocate space for device info */ |
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100 | | - data = devm_kzalloc(&pdev->dev, sizeof(struct pps_gpio_device_data), |
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101 | | - GFP_KERNEL); |
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| 173 | + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); |
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102 | 174 | if (!data) |
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103 | 175 | return -ENOMEM; |
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| 176 | + platform_set_drvdata(pdev, data); |
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104 | 177 | |
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| 178 | + /* GPIO setup */ |
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105 | 179 | if (pdata) { |
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106 | 180 | data->gpio_pin = pdata->gpio_pin; |
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107 | | - gpio_label = pdata->gpio_label; |
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| 181 | + data->echo_pin = pdata->echo_pin; |
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108 | 182 | |
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109 | 183 | data->assert_falling_edge = pdata->assert_falling_edge; |
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110 | 184 | data->capture_clear = pdata->capture_clear; |
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| 185 | + data->echo_active_ms = pdata->echo_active_ms; |
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111 | 186 | } else { |
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112 | | - ret = of_get_gpio(np, 0); |
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113 | | - if (ret < 0) { |
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114 | | - dev_err(&pdev->dev, "failed to get GPIO from device tree\n"); |
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115 | | - return ret; |
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116 | | - } |
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117 | | - data->gpio_pin = ret; |
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118 | | - gpio_label = PPS_GPIO_NAME; |
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119 | | - |
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120 | | - if (of_get_property(np, "assert-falling-edge", NULL)) |
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121 | | - data->assert_falling_edge = true; |
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122 | | - } |
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123 | | - |
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124 | | - /* GPIO setup */ |
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125 | | - ret = devm_gpio_request(&pdev->dev, data->gpio_pin, gpio_label); |
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126 | | - if (ret) { |
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127 | | - dev_err(&pdev->dev, "failed to request GPIO %u\n", |
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128 | | - data->gpio_pin); |
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129 | | - return ret; |
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130 | | - } |
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131 | | - |
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132 | | - ret = gpio_direction_input(data->gpio_pin); |
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133 | | - if (ret) { |
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134 | | - dev_err(&pdev->dev, "failed to set pin direction\n"); |
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135 | | - return -EINVAL; |
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| 187 | + ret = pps_gpio_setup(pdev); |
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| 188 | + if (ret) |
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| 189 | + return -EINVAL; |
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136 | 190 | } |
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137 | 191 | |
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138 | 192 | /* IRQ setup */ |
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139 | | - ret = gpio_to_irq(data->gpio_pin); |
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| 193 | + ret = gpiod_to_irq(data->gpio_pin); |
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140 | 194 | if (ret < 0) { |
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141 | 195 | dev_err(&pdev->dev, "failed to map GPIO to IRQ: %d\n", ret); |
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142 | 196 | return -EINVAL; |
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.. | .. |
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152 | 206 | data->info.owner = THIS_MODULE; |
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153 | 207 | snprintf(data->info.name, PPS_MAX_NAME_LEN - 1, "%s.%d", |
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154 | 208 | pdev->name, pdev->id); |
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| 209 | + if (data->echo_pin) { |
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| 210 | + data->info.echo = pps_gpio_echo; |
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| 211 | + data->echo_timeout = msecs_to_jiffies(data->echo_active_ms); |
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| 212 | + timer_setup(&data->echo_timer, pps_gpio_echo_timer_callback, 0); |
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| 213 | + } |
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155 | 214 | |
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156 | 215 | /* register PPS source */ |
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157 | 216 | pps_default_params = PPS_CAPTUREASSERT | PPS_OFFSETASSERT; |
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158 | 217 | if (data->capture_clear) |
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159 | 218 | pps_default_params |= PPS_CAPTURECLEAR | PPS_OFFSETCLEAR; |
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160 | 219 | data->pps = pps_register_source(&data->info, pps_default_params); |
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161 | | - if (data->pps == NULL) { |
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| 220 | + if (IS_ERR(data->pps)) { |
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162 | 221 | dev_err(&pdev->dev, "failed to register IRQ %d as PPS source\n", |
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163 | 222 | data->irq); |
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164 | | - return -EINVAL; |
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| 223 | + return PTR_ERR(data->pps); |
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165 | 224 | } |
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166 | 225 | |
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167 | 226 | /* register IRQ interrupt handler */ |
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.. | .. |
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173 | 232 | return -EINVAL; |
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174 | 233 | } |
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175 | 234 | |
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176 | | - platform_set_drvdata(pdev, data); |
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177 | 235 | dev_info(data->pps->dev, "Registered IRQ %d as PPS source\n", |
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178 | 236 | data->irq); |
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179 | 237 | |
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.. | .. |
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185 | 243 | struct pps_gpio_device_data *data = platform_get_drvdata(pdev); |
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186 | 244 | |
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187 | 245 | pps_unregister_source(data->pps); |
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| 246 | + if (data->echo_pin) { |
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| 247 | + del_timer_sync(&data->echo_timer); |
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| 248 | + /* reset echo pin in any case */ |
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| 249 | + gpiod_set_value(data->echo_pin, 0); |
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| 250 | + } |
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188 | 251 | dev_info(&pdev->dev, "removed IRQ %d as PPS source\n", data->irq); |
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189 | 252 | return 0; |
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190 | 253 | } |
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.. | .. |
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209 | 272 | MODULE_AUTHOR("James Nuss <jamesnuss@nanometrics.ca>"); |
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210 | 273 | MODULE_DESCRIPTION("Use GPIO pin as PPS source"); |
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211 | 274 | MODULE_LICENSE("GPL"); |
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212 | | -MODULE_VERSION("1.0.0"); |
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| 275 | +MODULE_VERSION("1.2.0"); |
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