drivers/gpu/drm/omapdrm/displays/connector-dvi.c

   1 /*
   2  * Generic DVI Connector driver
   3  *
   4  * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com/
   5  * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 as published by
   9  * the Free Software Foundation.
  10  */
  11
  12 #include <linux/gpio/consumer.h>
  13 #include <linux/i2c.h>
  14 #include <linux/module.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/slab.h>
  17
  18 #include <drm/drm_edid.h>
  19
  20 #include "../dss/omapdss.h"
  21
  22 struct panel_drv_data {
  23         struct omap_dss_device dssdev;
  24
  25         struct i2c_adapter *i2c_adapter;
  26
  27         struct gpio_desc *hpd_gpio;
  28
  29         void (*hpd_cb)(void *cb_data, enum drm_connector_status status);
  30         void *hpd_cb_data;
  31         bool hpd_enabled;
  32         /* mutex for hpd fields above */
  33         struct mutex hpd_lock;
  34 };
  35
  36 #define to_panel_data(x) container_of(x, struct panel_drv_data, dssdev)
  37
  38 static int dvic_connect(struct omap_dss_device *src,
  39                         struct omap_dss_device *dst)
  40 {
  41         return 0;
  42 }
  43
  44 static void dvic_disconnect(struct omap_dss_device *src,
  45                             struct omap_dss_device *dst)
  46 {
  47 }
  48
  49 static int dvic_ddc_read(struct i2c_adapter *adapter,
  50                 unsigned char *buf, u16 count, u8 offset)
  51 {
  52         int r, retries;
  53
  54         for (retries = 3; retries > 0; retries--) {
  55                 struct i2c_msg msgs[] = {
  56                         {
  57                                 .addr   = DDC_ADDR,
  58                                 .flags  = 0,
  59                                 .len    = 1,
  60                                 .buf    = &offset,
  61                         }, {
  62                                 .addr   = DDC_ADDR,
  63                                 .flags  = I2C_M_RD,
  64                                 .len    = count,
  65                                 .buf    = buf,
  66                         }
  67                 };
  68
  69                 r = i2c_transfer(adapter, msgs, 2);
  70                 if (r == 2)
  71                         return 0;
  72
  73                 if (r != -EAGAIN)
  74                         break;
  75         }
  76
  77         return r < 0 ? r : -EIO;
  78 }
  79
  80 static int dvic_read_edid(struct omap_dss_device *dssdev,
  81                 u8 *edid, int len)
  82 {
  83         struct panel_drv_data *ddata = to_panel_data(dssdev);
  84         int r, l, bytes_read;
  85
  86         l = min(EDID_LENGTH, len);
  87         r = dvic_ddc_read(ddata->i2c_adapter, edid, l, 0);
  88         if (r)
  89                 return r;
  90
  91         bytes_read = l;
  92
  93         /* if there are extensions, read second block */
  94         if (len > EDID_LENGTH && edid[0x7e] > 0) {
  95                 l = min(EDID_LENGTH, len - EDID_LENGTH);
  96
  97                 r = dvic_ddc_read(ddata->i2c_adapter, edid + EDID_LENGTH,
  98                                 l, EDID_LENGTH);
  99                 if (r)
 100                         return r;
 101
 102                 bytes_read += l;
 103         }
 104
 105         return bytes_read;
 106 }
 107
 108 static bool dvic_detect(struct omap_dss_device *dssdev)
 109 {
 110         struct panel_drv_data *ddata = to_panel_data(dssdev);
 111         unsigned char out;
 112         int r;
 113
 114         if (ddata->hpd_gpio)
 115                 return gpiod_get_value_cansleep(ddata->hpd_gpio);
 116
 117         if (!ddata->i2c_adapter)
 118                 return true;
 119
 120         r = dvic_ddc_read(ddata->i2c_adapter, &out, 1, 0);
 121
 122         return r == 0;
 123 }
 124
 125 static void dvic_register_hpd_cb(struct omap_dss_device *dssdev,
 126                                  void (*cb)(void *cb_data,
 127                                             enum drm_connector_status status),
 128                                  void *cb_data)
 129 {
 130         struct panel_drv_data *ddata = to_panel_data(dssdev);
 131
 132         mutex_lock(&ddata->hpd_lock);
 133         ddata->hpd_cb = cb;
 134         ddata->hpd_cb_data = cb_data;
 135         mutex_unlock(&ddata->hpd_lock);
 136 }
 137
 138 static void dvic_unregister_hpd_cb(struct omap_dss_device *dssdev)
 139 {
 140         struct panel_drv_data *ddata = to_panel_data(dssdev);
 141
 142         mutex_lock(&ddata->hpd_lock);
 143         ddata->hpd_cb = NULL;
 144         ddata->hpd_cb_data = NULL;
 145         mutex_unlock(&ddata->hpd_lock);
 146 }
 147
 148 static const struct omap_dss_device_ops dvic_ops = {
 149         .connect        = dvic_connect,
 150         .disconnect     = dvic_disconnect,
 151
 152         .read_edid      = dvic_read_edid,
 153         .detect         = dvic_detect,
 154
 155         .register_hpd_cb        = dvic_register_hpd_cb,
 156         .unregister_hpd_cb      = dvic_unregister_hpd_cb,
 157 };
 158
 159 static irqreturn_t dvic_hpd_isr(int irq, void *data)
 160 {
 161         struct panel_drv_data *ddata = data;
 162
 163         mutex_lock(&ddata->hpd_lock);
 164         if (ddata->hpd_enabled && ddata->hpd_cb) {
 165                 enum drm_connector_status status;
 166
 167                 if (dvic_detect(&ddata->dssdev))
 168                         status = connector_status_connected;
 169                 else
 170                         status = connector_status_disconnected;
 171
 172                 ddata->hpd_cb(ddata->hpd_cb_data, status);
 173         }
 174         mutex_unlock(&ddata->hpd_lock);
 175
 176         return IRQ_HANDLED;
 177 }
 178
 179 static int dvic_probe_of(struct platform_device *pdev)
 180 {
 181         struct panel_drv_data *ddata = platform_get_drvdata(pdev);
 182         struct device_node *node = pdev->dev.of_node;
 183         struct device_node *adapter_node;
 184         struct i2c_adapter *adapter;
 185         struct gpio_desc *gpio;
 186         int r;
 187
 188         gpio = devm_gpiod_get_optional(&pdev->dev, "hpd", GPIOD_IN);
 189         if (IS_ERR(gpio)) {
 190                 dev_err(&pdev->dev, "failed to parse HPD gpio\n");
 191                 return PTR_ERR(gpio);
 192         }
 193
 194         ddata->hpd_gpio = gpio;
 195
 196         mutex_init(&ddata->hpd_lock);
 197
 198         if (ddata->hpd_gpio) {
 199                 r = devm_request_threaded_irq(&pdev->dev,
 200                         gpiod_to_irq(ddata->hpd_gpio), NULL, dvic_hpd_isr,
 201                         IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 202                         "DVI HPD", ddata);
 203                 if (r)
 204                         return r;
 205         }
 206
 207         adapter_node = of_parse_phandle(node, "ddc-i2c-bus", 0);
 208         if (adapter_node) {
 209                 adapter = of_get_i2c_adapter_by_node(adapter_node);
 210                 of_node_put(adapter_node);
 211                 if (adapter == NULL) {
 212                         dev_err(&pdev->dev, "failed to parse ddc-i2c-bus\n");
 213                         return -EPROBE_DEFER;
 214                 }
 215
 216                 ddata->i2c_adapter = adapter;
 217         }
 218
 219         return 0;
 220 }
 221
 222 static int dvic_probe(struct platform_device *pdev)
 223 {
 224         struct panel_drv_data *ddata;
 225         struct omap_dss_device *dssdev;
 226         int r;
 227
 228         ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
 229         if (!ddata)
 230                 return -ENOMEM;
 231
 232         platform_set_drvdata(pdev, ddata);
 233
 234         r = dvic_probe_of(pdev);
 235         if (r)
 236                 return r;
 237
 238         dssdev = &ddata->dssdev;
 239         dssdev->ops = &dvic_ops;
 240         dssdev->dev = &pdev->dev;
 241         dssdev->type = OMAP_DISPLAY_TYPE_DVI;
 242         dssdev->display = true;
 243         dssdev->owner = THIS_MODULE;
 244         dssdev->of_ports = BIT(0);
 245
 246         if (ddata->hpd_gpio)
 247                 dssdev->ops_flags |= OMAP_DSS_DEVICE_OP_DETECT
 248                                   |  OMAP_DSS_DEVICE_OP_HPD;
 249         if (ddata->i2c_adapter)
 250                 dssdev->ops_flags |= OMAP_DSS_DEVICE_OP_DETECT
 251                                   |  OMAP_DSS_DEVICE_OP_EDID;
 252
 253         omapdss_display_init(dssdev);
 254         omapdss_device_register(dssdev);
 255
 256         return 0;
 257 }
 258
 259 static int __exit dvic_remove(struct platform_device *pdev)
 260 {
 261         struct panel_drv_data *ddata = platform_get_drvdata(pdev);
 262
 263         omapdss_device_unregister(&ddata->dssdev);
 264
 265         i2c_put_adapter(ddata->i2c_adapter);
 266
 267         mutex_destroy(&ddata->hpd_lock);
 268
 269         return 0;
 270 }
 271
 272 static const struct of_device_id dvic_of_match[] = {
 273         { .compatible = "omapdss,dvi-connector", },
 274         {},
 275 };
 276
 277 MODULE_DEVICE_TABLE(of, dvic_of_match);
 278
 279 static struct platform_driver dvi_connector_driver = {
 280         .probe  = dvic_probe,
 281         .remove = __exit_p(dvic_remove),
 282         .driver = {
 283                 .name   = "connector-dvi",
 284                 .of_match_table = dvic_of_match,
 285                 .suppress_bind_attrs = true,
 286         },
 287 };
 288
 289 module_platform_driver(dvi_connector_driver);
 290
 291 MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
 292 MODULE_DESCRIPTION("Generic DVI Connector driver");
 293 MODULE_LICENSE("GPL");