diff options
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/drm_edid.c | 121 |
1 files changed, 93 insertions, 28 deletions
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index a839a28d8ee..fab2bdf9c42 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -550,11 +550,20 @@ static int add_detailed_info(struct drm_connector *connector, } #define DDC_ADDR 0x50 - -unsigned char *drm_do_probe_ddc_edid(struct i2c_adapter *adapter) +/** + * Get EDID information via I2C. + * + * \param adapter : i2c device adaptor + * \param buf : EDID data buffer to be filled + * \param len : EDID data buffer length + * \return 0 on success or -1 on failure. + * + * Try to fetch EDID information by calling i2c driver function. + */ +int drm_do_probe_ddc_edid(struct i2c_adapter *adapter, + unsigned char *buf, int len) { unsigned char start = 0x0; - unsigned char *buf = kmalloc(EDID_LENGTH, GFP_KERNEL); struct i2c_msg msgs[] = { { .addr = DDC_ADDR, @@ -564,31 +573,36 @@ unsigned char *drm_do_probe_ddc_edid(struct i2c_adapter *adapter) }, { .addr = DDC_ADDR, .flags = I2C_M_RD, - .len = EDID_LENGTH, + .len = len, .buf = buf, } }; - if (!buf) { - dev_warn(&adapter->dev, "unable to allocate memory for EDID " - "block.\n"); - return NULL; - } - if (i2c_transfer(adapter, msgs, 2) == 2) - return buf; + return 0; dev_info(&adapter->dev, "unable to read EDID block.\n"); - kfree(buf); - return NULL; + return -1; } EXPORT_SYMBOL(drm_do_probe_ddc_edid); -static unsigned char *drm_ddc_read(struct i2c_adapter *adapter) +/** + * Get EDID information. + * + * \param adapter : i2c device adaptor. + * \param buf : EDID data buffer to be filled + * \param len : EDID data buffer length + * \return 0 on success or -1 on failure. + * + * Initialize DDC, then fetch EDID information + * by calling drm_do_probe_ddc_edid function. + */ +static int drm_ddc_read(struct i2c_adapter *adapter, + unsigned char *buf, int len) { struct i2c_algo_bit_data *algo_data = adapter->algo_data; - unsigned char *edid = NULL; int i, j; + int ret = -1; algo_data->setscl(algo_data->data, 1); @@ -616,7 +630,7 @@ static unsigned char *drm_ddc_read(struct i2c_adapter *adapter) msleep(15); /* Do the real work */ - edid = drm_do_probe_ddc_edid(adapter); + ret = drm_do_probe_ddc_edid(adapter, buf, len); algo_data->setsda(algo_data->data, 0); algo_data->setscl(algo_data->data, 0); msleep(15); @@ -632,7 +646,7 @@ static unsigned char *drm_ddc_read(struct i2c_adapter *adapter) msleep(15); algo_data->setscl(algo_data->data, 0); algo_data->setsda(algo_data->data, 0); - if (edid) + if (ret == 0) break; } /* Release the DDC lines when done or the Apple Cinema HD display @@ -641,9 +655,31 @@ static unsigned char *drm_ddc_read(struct i2c_adapter *adapter) algo_data->setsda(algo_data->data, 1); algo_data->setscl(algo_data->data, 1); - return edid; + return ret; +} + +static int drm_ddc_read_edid(struct drm_connector *connector, + struct i2c_adapter *adapter, + char *buf, int len) +{ + int ret; + + ret = drm_ddc_read(adapter, buf, len); + if (ret != 0) { + dev_info(&connector->dev->pdev->dev, "%s: no EDID data\n", + drm_get_connector_name(connector)); + goto end; + } + if (!edid_is_valid((struct edid *)buf)) { + dev_warn(&connector->dev->pdev->dev, "%s: EDID invalid.\n", + drm_get_connector_name(connector)); + ret = -1; + } +end: + return ret; } +#define MAX_EDID_EXT_NUM 4 /** * drm_get_edid - get EDID data, if available * @connector: connector we're probing @@ -656,24 +692,53 @@ static unsigned char *drm_ddc_read(struct i2c_adapter *adapter) struct edid *drm_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter) { + int ret; struct edid *edid; - edid = (struct edid *)drm_ddc_read(adapter); - if (!edid) { - dev_info(&connector->dev->pdev->dev, "%s: no EDID data\n", - drm_get_connector_name(connector)); - return NULL; + edid = kmalloc(EDID_LENGTH * (MAX_EDID_EXT_NUM + 1), + GFP_KERNEL); + if (edid == NULL) { + dev_warn(&connector->dev->pdev->dev, + "Failed to allocate EDID\n"); + goto end; } - if (!edid_is_valid(edid)) { - dev_warn(&connector->dev->pdev->dev, "%s: EDID invalid.\n", - drm_get_connector_name(connector)); - kfree(edid); - return NULL; + + /* Read first EDID block */ + ret = drm_ddc_read_edid(connector, adapter, + (unsigned char *)edid, EDID_LENGTH); + if (ret != 0) + goto clean_up; + + /* There are EDID extensions to be read */ + if (edid->extensions != 0) { + int edid_ext_num = edid->extensions; + + if (edid_ext_num > MAX_EDID_EXT_NUM) { + dev_warn(&connector->dev->pdev->dev, + "The number of extension(%d) is " + "over max (%d), actually read number (%d)\n", + edid_ext_num, MAX_EDID_EXT_NUM, + MAX_EDID_EXT_NUM); + /* Reset EDID extension number to be read */ + edid_ext_num = MAX_EDID_EXT_NUM; + } + /* Read EDID including extensions too */ + ret = drm_ddc_read_edid(connector, adapter, (char *)edid, + EDID_LENGTH * (edid_ext_num + 1)); + if (ret != 0) + goto clean_up; + } connector->display_info.raw_edid = (char *)edid; + goto end; +clean_up: + kfree(edid); + edid = NULL; +end: return edid; + } EXPORT_SYMBOL(drm_get_edid); |