1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * STMicroelectronics Key Scanning driver 4 * 5 * Copyright (c) 2014 STMicroelectonics Ltd. 6 * Author: Stuart Menefy <stuart.menefy@st.com> 7 * 8 * Based on sh_keysc.c, copyright 2008 Magnus Damm 9 */ 10 11 #include <linux/clk.h> 12 #include <linux/input.h> 13 #include <linux/input/matrix_keypad.h> 14 #include <linux/io.h> 15 #include <linux/interrupt.h> 16 #include <linux/module.h> 17 #include <linux/of.h> 18 #include <linux/platform_device.h> 19 20 #define ST_KEYSCAN_MAXKEYS 16 21 22 #define KEYSCAN_CONFIG_OFF 0x0 23 #define KEYSCAN_CONFIG_ENABLE 0x1 24 #define KEYSCAN_DEBOUNCE_TIME_OFF 0x4 25 #define KEYSCAN_MATRIX_STATE_OFF 0x8 26 #define KEYSCAN_MATRIX_DIM_OFF 0xc 27 #define KEYSCAN_MATRIX_DIM_X_SHIFT 0x0 28 #define KEYSCAN_MATRIX_DIM_Y_SHIFT 0x2 29 30 struct st_keyscan { 31 void __iomem *base; 32 int irq; 33 struct clk *clk; 34 struct input_dev *input_dev; 35 unsigned long last_state; 36 unsigned int n_rows; 37 unsigned int n_cols; 38 unsigned int debounce_us; 39 }; 40 41 static irqreturn_t keyscan_isr(int irq, void *dev_id) 42 { 43 struct st_keyscan *keypad = dev_id; 44 unsigned short *keycode = keypad->input_dev->keycode; 45 unsigned long state, change; 46 int bit_nr; 47 48 state = readl(keypad->base + KEYSCAN_MATRIX_STATE_OFF) & 0xffff; 49 change = keypad->last_state ^ state; 50 keypad->last_state = state; 51 52 for_each_set_bit(bit_nr, &change, BITS_PER_LONG) 53 input_report_key(keypad->input_dev, 54 keycode[bit_nr], state & BIT(bit_nr)); 55 56 input_sync(keypad->input_dev); 57 58 return IRQ_HANDLED; 59 } 60 61 static int keyscan_start(struct st_keyscan *keypad) 62 { 63 int error; 64 65 error = clk_enable(keypad->clk); 66 if (error) 67 return error; 68 69 writel(keypad->debounce_us * (clk_get_rate(keypad->clk) / 1000000), 70 keypad->base + KEYSCAN_DEBOUNCE_TIME_OFF); 71 72 writel(((keypad->n_cols - 1) << KEYSCAN_MATRIX_DIM_X_SHIFT) | 73 ((keypad->n_rows - 1) << KEYSCAN_MATRIX_DIM_Y_SHIFT), 74 keypad->base + KEYSCAN_MATRIX_DIM_OFF); 75 76 writel(KEYSCAN_CONFIG_ENABLE, keypad->base + KEYSCAN_CONFIG_OFF); 77 78 return 0; 79 } 80 81 static void keyscan_stop(struct st_keyscan *keypad) 82 { 83 writel(0, keypad->base + KEYSCAN_CONFIG_OFF); 84 85 clk_disable(keypad->clk); 86 } 87 88 static int keyscan_open(struct input_dev *dev) 89 { 90 struct st_keyscan *keypad = input_get_drvdata(dev); 91 92 return keyscan_start(keypad); 93 } 94 95 static void keyscan_close(struct input_dev *dev) 96 { 97 struct st_keyscan *keypad = input_get_drvdata(dev); 98 99 keyscan_stop(keypad); 100 } 101 102 static int keypad_matrix_key_parse_dt(struct st_keyscan *keypad_data) 103 { 104 struct device *dev = keypad_data->input_dev->dev.parent; 105 struct device_node *np = dev->of_node; 106 int error; 107 108 error = matrix_keypad_parse_properties(dev, &keypad_data->n_rows, 109 &keypad_data->n_cols); 110 if (error) { 111 dev_err(dev, "failed to parse keypad params\n"); 112 return error; 113 } 114 115 of_property_read_u32(np, "st,debounce-us", &keypad_data->debounce_us); 116 117 dev_dbg(dev, "n_rows=%d n_col=%d debounce=%d\n", 118 keypad_data->n_rows, keypad_data->n_cols, 119 keypad_data->debounce_us); 120 121 return 0; 122 } 123 124 static int keyscan_probe(struct platform_device *pdev) 125 { 126 struct st_keyscan *keypad_data; 127 struct input_dev *input_dev; 128 struct resource *res; 129 int error; 130 131 if (!pdev->dev.of_node) { 132 dev_err(&pdev->dev, "no DT data present\n"); 133 return -EINVAL; 134 } 135 136 keypad_data = devm_kzalloc(&pdev->dev, sizeof(*keypad_data), 137 GFP_KERNEL); 138 if (!keypad_data) 139 return -ENOMEM; 140 141 input_dev = devm_input_allocate_device(&pdev->dev); 142 if (!input_dev) { 143 dev_err(&pdev->dev, "failed to allocate the input device\n"); 144 return -ENOMEM; 145 } 146 147 input_dev->name = pdev->name; 148 input_dev->phys = "keyscan-keys/input0"; 149 input_dev->dev.parent = &pdev->dev; 150 input_dev->open = keyscan_open; 151 input_dev->close = keyscan_close; 152 153 input_dev->id.bustype = BUS_HOST; 154 155 keypad_data->input_dev = input_dev; 156 157 error = keypad_matrix_key_parse_dt(keypad_data); 158 if (error) 159 return error; 160 161 error = matrix_keypad_build_keymap(NULL, NULL, 162 keypad_data->n_rows, 163 keypad_data->n_cols, 164 NULL, input_dev); 165 if (error) { 166 dev_err(&pdev->dev, "failed to build keymap\n"); 167 return error; 168 } 169 170 input_set_drvdata(input_dev, keypad_data); 171 172 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 173 keypad_data->base = devm_ioremap_resource(&pdev->dev, res); 174 if (IS_ERR(keypad_data->base)) 175 return PTR_ERR(keypad_data->base); 176 177 keypad_data->clk = devm_clk_get(&pdev->dev, NULL); 178 if (IS_ERR(keypad_data->clk)) { 179 dev_err(&pdev->dev, "cannot get clock\n"); 180 return PTR_ERR(keypad_data->clk); 181 } 182 183 error = clk_enable(keypad_data->clk); 184 if (error) { 185 dev_err(&pdev->dev, "failed to enable clock\n"); 186 return error; 187 } 188 189 keyscan_stop(keypad_data); 190 191 keypad_data->irq = platform_get_irq(pdev, 0); 192 if (keypad_data->irq < 0) 193 return -EINVAL; 194 195 error = devm_request_irq(&pdev->dev, keypad_data->irq, keyscan_isr, 0, 196 pdev->name, keypad_data); 197 if (error) { 198 dev_err(&pdev->dev, "failed to request IRQ\n"); 199 return error; 200 } 201 202 error = input_register_device(input_dev); 203 if (error) { 204 dev_err(&pdev->dev, "failed to register input device\n"); 205 return error; 206 } 207 208 platform_set_drvdata(pdev, keypad_data); 209 210 device_set_wakeup_capable(&pdev->dev, 1); 211 212 return 0; 213 } 214 215 static int keyscan_suspend(struct device *dev) 216 { 217 struct platform_device *pdev = to_platform_device(dev); 218 struct st_keyscan *keypad = platform_get_drvdata(pdev); 219 struct input_dev *input = keypad->input_dev; 220 221 mutex_lock(&input->mutex); 222 223 if (device_may_wakeup(dev)) 224 enable_irq_wake(keypad->irq); 225 else if (input_device_enabled(input)) 226 keyscan_stop(keypad); 227 228 mutex_unlock(&input->mutex); 229 return 0; 230 } 231 232 static int keyscan_resume(struct device *dev) 233 { 234 struct platform_device *pdev = to_platform_device(dev); 235 struct st_keyscan *keypad = platform_get_drvdata(pdev); 236 struct input_dev *input = keypad->input_dev; 237 int retval = 0; 238 239 mutex_lock(&input->mutex); 240 241 if (device_may_wakeup(dev)) 242 disable_irq_wake(keypad->irq); 243 else if (input_device_enabled(input)) 244 retval = keyscan_start(keypad); 245 246 mutex_unlock(&input->mutex); 247 return retval; 248 } 249 250 static DEFINE_SIMPLE_DEV_PM_OPS(keyscan_dev_pm_ops, 251 keyscan_suspend, keyscan_resume); 252 253 static const struct of_device_id keyscan_of_match[] = { 254 { .compatible = "st,sti-keyscan" }, 255 { }, 256 }; 257 MODULE_DEVICE_TABLE(of, keyscan_of_match); 258 259 static struct platform_driver keyscan_device_driver = { 260 .probe = keyscan_probe, 261 .driver = { 262 .name = "st-keyscan", 263 .pm = pm_sleep_ptr(&keyscan_dev_pm_ops), 264 .of_match_table = of_match_ptr(keyscan_of_match), 265 } 266 }; 267 268 module_platform_driver(keyscan_device_driver); 269 270 MODULE_AUTHOR("Stuart Menefy <stuart.menefy@st.com>"); 271 MODULE_DESCRIPTION("STMicroelectronics keyscan device driver"); 272 MODULE_LICENSE("GPL"); 273