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