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 <asm/io.h> 27 #include <linux/i2c.h> 28 #include <linux/timer.h> 29 30 #define EVENT_PENDOWN 1 31 #define EVENT_REPEAT 2 32 #define EVENT_PENUP 3 33 34 struct migor_ts_priv { 35 struct i2c_client *client; 36 struct input_dev *input; 37 struct delayed_work work; 38 int irq; 39 }; 40 41 static const u_int8_t migor_ts_ena_seq[17] = { 0x33, 0x22, 0x11, 42 0x01, 0x06, 0x07, }; 43 static const u_int8_t migor_ts_dis_seq[17] = { }; 44 45 static void migor_ts_poscheck(struct work_struct *work) 46 { 47 struct migor_ts_priv *priv = container_of(work, 48 struct migor_ts_priv, 49 work.work); 50 unsigned short xpos, ypos; 51 unsigned char event; 52 u_int8_t buf[16]; 53 54 memset(buf, 0, sizeof(buf)); 55 56 /* Set Index 0 */ 57 buf[0] = 0; 58 if (i2c_master_send(priv->client, buf, 1) != 1) { 59 dev_err(&priv->client->dev, "Unable to write i2c index\n"); 60 goto out; 61 } 62 63 /* Now do Page Read */ 64 if (i2c_master_recv(priv->client, buf, sizeof(buf)) != sizeof(buf)) { 65 dev_err(&priv->client->dev, "Unable to read i2c page\n"); 66 goto out; 67 } 68 69 ypos = ((buf[9] & 0x03) << 8 | buf[8]); 70 xpos = ((buf[11] & 0x03) << 8 | buf[10]); 71 event = buf[12]; 72 73 if (event == EVENT_PENDOWN || event == EVENT_REPEAT) { 74 input_report_key(priv->input, BTN_TOUCH, 1); 75 input_report_abs(priv->input, ABS_X, ypos); /*X-Y swap*/ 76 input_report_abs(priv->input, ABS_Y, xpos); 77 input_sync(priv->input); 78 } else if (event == EVENT_PENUP) { 79 input_report_key(priv->input, BTN_TOUCH, 0); 80 input_sync(priv->input); 81 } 82 out: 83 enable_irq(priv->irq); 84 } 85 86 static irqreturn_t migor_ts_isr(int irq, void *dev_id) 87 { 88 struct migor_ts_priv *priv = dev_id; 89 90 /* the touch screen controller chip is hooked up to the cpu 91 * using i2c and a single interrupt line. the interrupt line 92 * is pulled low whenever someone taps the screen. to deassert 93 * the interrupt line we need to acknowledge the interrupt by 94 * communicating with the controller over the slow i2c bus. 95 * 96 * we can't acknowledge from interrupt context since the i2c 97 * bus controller may sleep, so we just disable the interrupt 98 * here and handle the acknowledge using delayed work. 99 */ 100 101 disable_irq_nosync(irq); 102 schedule_delayed_work(&priv->work, HZ / 20); 103 104 return IRQ_HANDLED; 105 } 106 107 108 static int migor_ts_open(struct input_dev *dev) 109 { 110 struct migor_ts_priv *priv = input_get_drvdata(dev); 111 struct i2c_client *client = priv->client; 112 int count; 113 114 /* enable controller */ 115 count = i2c_master_send(client, migor_ts_ena_seq, 116 sizeof(migor_ts_ena_seq)); 117 if (count != sizeof(migor_ts_ena_seq)) { 118 dev_err(&client->dev, "Unable to enable touchscreen.\n"); 119 return -ENXIO; 120 } 121 122 return 0; 123 } 124 125 static void migor_ts_close(struct input_dev *dev) 126 { 127 struct migor_ts_priv *priv = input_get_drvdata(dev); 128 struct i2c_client *client = priv->client; 129 130 disable_irq(priv->irq); 131 132 /* cancel pending work and wait for migor_ts_poscheck() to finish */ 133 if (cancel_delayed_work_sync(&priv->work)) { 134 /* 135 * if migor_ts_poscheck was canceled we need to enable IRQ 136 * here to balance disable done in migor_ts_isr. 137 */ 138 enable_irq(priv->irq); 139 } 140 141 /* disable controller */ 142 i2c_master_send(client, migor_ts_dis_seq, sizeof(migor_ts_dis_seq)); 143 144 enable_irq(priv->irq); 145 } 146 147 static int migor_ts_probe(struct i2c_client *client, 148 const struct i2c_device_id *idp) 149 { 150 struct migor_ts_priv *priv; 151 struct input_dev *input; 152 int error; 153 154 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 155 if (!priv) { 156 dev_err(&client->dev, "failed to allocate driver data\n"); 157 error = -ENOMEM; 158 goto err0; 159 } 160 161 dev_set_drvdata(&client->dev, priv); 162 163 input = input_allocate_device(); 164 if (!input) { 165 dev_err(&client->dev, "Failed to allocate input device.\n"); 166 error = -ENOMEM; 167 goto err1; 168 } 169 170 input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 171 input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 172 173 input_set_abs_params(input, ABS_X, 95, 955, 0, 0); 174 input_set_abs_params(input, ABS_Y, 85, 935, 0, 0); 175 176 input->name = client->name; 177 input->id.bustype = BUS_I2C; 178 input->dev.parent = &client->dev; 179 180 input->open = migor_ts_open; 181 input->close = migor_ts_close; 182 183 input_set_drvdata(input, priv); 184 185 priv->client = client; 186 priv->input = input; 187 INIT_DELAYED_WORK(&priv->work, migor_ts_poscheck); 188 priv->irq = client->irq; 189 190 error = input_register_device(input); 191 if (error) 192 goto err1; 193 194 error = request_irq(priv->irq, migor_ts_isr, IRQF_TRIGGER_LOW, 195 client->name, priv); 196 if (error) { 197 dev_err(&client->dev, "Unable to request touchscreen IRQ.\n"); 198 goto err2; 199 } 200 201 return 0; 202 203 err2: 204 input_unregister_device(input); 205 input = NULL; /* so we dont try to free it below */ 206 err1: 207 input_free_device(input); 208 kfree(priv); 209 err0: 210 dev_set_drvdata(&client->dev, NULL); 211 return error; 212 } 213 214 static int migor_ts_remove(struct i2c_client *client) 215 { 216 struct migor_ts_priv *priv = dev_get_drvdata(&client->dev); 217 218 free_irq(priv->irq, priv); 219 input_unregister_device(priv->input); 220 kfree(priv); 221 222 dev_set_drvdata(&client->dev, NULL); 223 224 return 0; 225 } 226 227 static const struct i2c_device_id migor_ts_id[] = { 228 { "migor_ts", 0 }, 229 { } 230 }; 231 MODULE_DEVICE_TABLE(i2c, migor_ts); 232 233 static struct i2c_driver migor_ts_driver = { 234 .driver = { 235 .name = "migor_ts", 236 }, 237 .probe = migor_ts_probe, 238 .remove = migor_ts_remove, 239 .id_table = migor_ts_id, 240 }; 241 242 static int __init migor_ts_init(void) 243 { 244 return i2c_add_driver(&migor_ts_driver); 245 } 246 247 static void __exit migor_ts_exit(void) 248 { 249 i2c_del_driver(&migor_ts_driver); 250 } 251 252 MODULE_DESCRIPTION("MigoR Touchscreen driver"); 253 MODULE_AUTHOR("Magnus Damm <damm@opensource.se>"); 254 MODULE_LICENSE("GPL"); 255 256 module_init(migor_ts_init); 257 module_exit(migor_ts_exit); 258