1 /* 2 * Touch Screen driver for Renesas MIGO-R Platform 3 * 4 * Copyright (c) 2008 Magnus Damm 5 * Copyright (c) 2007 Ujjwal Pande <ujjwal@kenati.com>, 6 * Kenati Technologies Pvt Ltd. 7 * 8 * This file is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public 10 * License as published by the Free Software Foundation; either 11 * version 2 of the License, or (at your option) any later version. 12 * 13 * This file is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public 19 * License along with this library; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21 */ 22 #include <linux/module.h> 23 #include <linux/kernel.h> 24 #include <linux/input.h> 25 #include <linux/interrupt.h> 26 #include <linux/pm.h> 27 #include <linux/slab.h> 28 #include <asm/io.h> 29 #include <linux/i2c.h> 30 #include <linux/timer.h> 31 32 #define EVENT_PENDOWN 1 33 #define EVENT_REPEAT 2 34 #define EVENT_PENUP 3 35 36 struct migor_ts_priv { 37 struct i2c_client *client; 38 struct input_dev *input; 39 struct delayed_work work; 40 int irq; 41 }; 42 43 static const u_int8_t migor_ts_ena_seq[17] = { 0x33, 0x22, 0x11, 44 0x01, 0x06, 0x07, }; 45 static const u_int8_t migor_ts_dis_seq[17] = { }; 46 47 static void migor_ts_poscheck(struct work_struct *work) 48 { 49 struct migor_ts_priv *priv = container_of(work, 50 struct migor_ts_priv, 51 work.work); 52 unsigned short xpos, ypos; 53 unsigned char event; 54 u_int8_t buf[16]; 55 56 memset(buf, 0, sizeof(buf)); 57 58 /* Set Index 0 */ 59 buf[0] = 0; 60 if (i2c_master_send(priv->client, buf, 1) != 1) { 61 dev_err(&priv->client->dev, "Unable to write i2c index\n"); 62 goto out; 63 } 64 65 /* Now do Page Read */ 66 if (i2c_master_recv(priv->client, buf, sizeof(buf)) != sizeof(buf)) { 67 dev_err(&priv->client->dev, "Unable to read i2c page\n"); 68 goto out; 69 } 70 71 ypos = ((buf[9] & 0x03) << 8 | buf[8]); 72 xpos = ((buf[11] & 0x03) << 8 | buf[10]); 73 event = buf[12]; 74 75 if (event == EVENT_PENDOWN || event == EVENT_REPEAT) { 76 input_report_key(priv->input, BTN_TOUCH, 1); 77 input_report_abs(priv->input, ABS_X, ypos); /*X-Y swap*/ 78 input_report_abs(priv->input, ABS_Y, xpos); 79 input_sync(priv->input); 80 } else if (event == EVENT_PENUP) { 81 input_report_key(priv->input, BTN_TOUCH, 0); 82 input_sync(priv->input); 83 } 84 out: 85 enable_irq(priv->irq); 86 } 87 88 static irqreturn_t migor_ts_isr(int irq, void *dev_id) 89 { 90 struct migor_ts_priv *priv = dev_id; 91 92 /* the touch screen controller chip is hooked up to the cpu 93 * using i2c and a single interrupt line. the interrupt line 94 * is pulled low whenever someone taps the screen. to deassert 95 * the interrupt line we need to acknowledge the interrupt by 96 * communicating with the controller over the slow i2c bus. 97 * 98 * we can't acknowledge from interrupt context since the i2c 99 * bus controller may sleep, so we just disable the interrupt 100 * here and handle the acknowledge using delayed work. 101 */ 102 103 disable_irq_nosync(irq); 104 schedule_delayed_work(&priv->work, HZ / 20); 105 106 return IRQ_HANDLED; 107 } 108 109 110 static int migor_ts_open(struct input_dev *dev) 111 { 112 struct migor_ts_priv *priv = input_get_drvdata(dev); 113 struct i2c_client *client = priv->client; 114 int count; 115 116 /* enable controller */ 117 count = i2c_master_send(client, migor_ts_ena_seq, 118 sizeof(migor_ts_ena_seq)); 119 if (count != sizeof(migor_ts_ena_seq)) { 120 dev_err(&client->dev, "Unable to enable touchscreen.\n"); 121 return -ENXIO; 122 } 123 124 return 0; 125 } 126 127 static void migor_ts_close(struct input_dev *dev) 128 { 129 struct migor_ts_priv *priv = input_get_drvdata(dev); 130 struct i2c_client *client = priv->client; 131 132 disable_irq(priv->irq); 133 134 /* cancel pending work and wait for migor_ts_poscheck() to finish */ 135 if (cancel_delayed_work_sync(&priv->work)) { 136 /* 137 * if migor_ts_poscheck was canceled we need to enable IRQ 138 * here to balance disable done in migor_ts_isr. 139 */ 140 enable_irq(priv->irq); 141 } 142 143 /* disable controller */ 144 i2c_master_send(client, migor_ts_dis_seq, sizeof(migor_ts_dis_seq)); 145 146 enable_irq(priv->irq); 147 } 148 149 static int migor_ts_probe(struct i2c_client *client, 150 const struct i2c_device_id *idp) 151 { 152 struct migor_ts_priv *priv; 153 struct input_dev *input; 154 int error; 155 156 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 157 if (!priv) { 158 dev_err(&client->dev, "failed to allocate driver data\n"); 159 error = -ENOMEM; 160 goto err0; 161 } 162 163 dev_set_drvdata(&client->dev, priv); 164 165 input = input_allocate_device(); 166 if (!input) { 167 dev_err(&client->dev, "Failed to allocate input device.\n"); 168 error = -ENOMEM; 169 goto err1; 170 } 171 172 input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 173 input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 174 175 input_set_abs_params(input, ABS_X, 95, 955, 0, 0); 176 input_set_abs_params(input, ABS_Y, 85, 935, 0, 0); 177 178 input->name = client->name; 179 input->id.bustype = BUS_I2C; 180 input->dev.parent = &client->dev; 181 182 input->open = migor_ts_open; 183 input->close = migor_ts_close; 184 185 input_set_drvdata(input, priv); 186 187 priv->client = client; 188 priv->input = input; 189 INIT_DELAYED_WORK(&priv->work, migor_ts_poscheck); 190 priv->irq = client->irq; 191 192 error = input_register_device(input); 193 if (error) 194 goto err1; 195 196 error = request_irq(priv->irq, migor_ts_isr, IRQF_TRIGGER_LOW, 197 client->name, priv); 198 if (error) { 199 dev_err(&client->dev, "Unable to request touchscreen IRQ.\n"); 200 goto err2; 201 } 202 203 device_init_wakeup(&client->dev, 1); 204 return 0; 205 206 err2: 207 input_unregister_device(input); 208 input = NULL; /* so we dont try to free it below */ 209 err1: 210 input_free_device(input); 211 kfree(priv); 212 err0: 213 dev_set_drvdata(&client->dev, NULL); 214 return error; 215 } 216 217 static int migor_ts_remove(struct i2c_client *client) 218 { 219 struct migor_ts_priv *priv = dev_get_drvdata(&client->dev); 220 221 free_irq(priv->irq, priv); 222 input_unregister_device(priv->input); 223 kfree(priv); 224 225 dev_set_drvdata(&client->dev, NULL); 226 227 return 0; 228 } 229 230 static int migor_ts_suspend(struct device *dev) 231 { 232 struct i2c_client *client = to_i2c_client(dev); 233 struct migor_ts_priv *priv = dev_get_drvdata(&client->dev); 234 235 if (device_may_wakeup(&client->dev)) 236 enable_irq_wake(priv->irq); 237 238 return 0; 239 } 240 241 static int migor_ts_resume(struct device *dev) 242 { 243 struct i2c_client *client = to_i2c_client(dev); 244 struct migor_ts_priv *priv = dev_get_drvdata(&client->dev); 245 246 if (device_may_wakeup(&client->dev)) 247 disable_irq_wake(priv->irq); 248 249 return 0; 250 } 251 252 static SIMPLE_DEV_PM_OPS(migor_ts_pm, migor_ts_suspend, migor_ts_resume); 253 254 static const struct i2c_device_id migor_ts_id[] = { 255 { "migor_ts", 0 }, 256 { } 257 }; 258 MODULE_DEVICE_TABLE(i2c, migor_ts); 259 260 static struct i2c_driver migor_ts_driver = { 261 .driver = { 262 .name = "migor_ts", 263 .pm = &migor_ts_pm, 264 }, 265 .probe = migor_ts_probe, 266 .remove = migor_ts_remove, 267 .id_table = migor_ts_id, 268 }; 269 270 static int __init migor_ts_init(void) 271 { 272 return i2c_add_driver(&migor_ts_driver); 273 } 274 275 static void __exit migor_ts_exit(void) 276 { 277 i2c_del_driver(&migor_ts_driver); 278 } 279 280 MODULE_DESCRIPTION("MigoR Touchscreen driver"); 281 MODULE_AUTHOR("Magnus Damm <damm@opensource.se>"); 282 MODULE_LICENSE("GPL"); 283 284 module_init(migor_ts_init); 285 module_exit(migor_ts_exit); 286