OMAP: DSS2: add panel-dvi driver

We have currently panel-generic-dpi driver, which is a combined driver
for dummy panels and also for DVI output.

The aim is to split the panel-generic-dpi into two, one for fixed size
dummy panels connected via DPI, and the other (this) for variable
resolution output which supports DDC channel (in practice a DVI framer
chip connected to DPI output).

Original i2c code by: Ricardo Salveti de Araujo
<ricardo.salveti@canonical.com>

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

3 files changed, 371 insertions, 0 deletions

diff --git a/drivers/video/omap2/displays/Kconfig b/drivers/video/omap2/displays/Kconfig
index 6ddb401552c..16e3eab444c 100644
--- a/drivers/video/omap2/displays/Kconfig
+++ b/drivers/video/omap2/displays/Kconfig
@@ -10,6 +10,13 @@ config PANEL_GENERIC_DPI
           Supports LCD Panel used in TI SDP3430 and EVM boards,
           OMAP3517 EVM boards and CM-T35.
 
+config PANEL_DVI
+        tristate "DVI output"
+        depends on OMAP2_DSS_DPI
+        help
+          Driver for external monitors, connected via DVI. The driver uses i2c
+          to read EDID information from the monitor.
+
 config PANEL_LGPHILIPS_LB035Q02
         tristate "LG.Philips LB035Q02 LCD Panel"
         depends on OMAP2_DSS_DPI && SPI
diff --git a/drivers/video/omap2/displays/Makefile b/drivers/video/omap2/displays/Makefile
index d90f73c8716..abfda35d82d 100644
--- a/drivers/video/omap2/displays/Makefile
+++ b/drivers/video/omap2/displays/Makefile
@@ -1,4 +1,5 @@
 obj-$(CONFIG_PANEL_GENERIC_DPI) += panel-generic-dpi.o
+obj-$(CONFIG_PANEL_DVI) += panel-dvi.o
 obj-$(CONFIG_PANEL_LGPHILIPS_LB035Q02) += panel-lgphilips-lb035q02.o
 obj-$(CONFIG_PANEL_SHARP_LS037V7DW01) += panel-sharp-ls037v7dw01.o
 obj-$(CONFIG_PANEL_NEC_NL8048HL11_01B) += panel-nec-nl8048hl11-01b.o
diff --git a/drivers/video/omap2/displays/panel-dvi.c b/drivers/video/omap2/displays/panel-dvi.c
new file mode 100644
index 00000000000..03eb14af33e
--- /dev/null
+++ b/drivers/video/omap2/displays/panel-dvi.c
@@ -0,0 +1,363 @@
+/*
+ * DVI output support
+ *
+ * Copyright (C) 2011 Texas Instruments Inc
+ * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <video/omapdss.h>
+#include <linux/i2c.h>
+#include <drm/drm_edid.h>
+
+#include <video/omap-panel-dvi.h>
+
+static const struct omap_video_timings panel_dvi_default_timings = {
+        .x_res          = 640,
+        .y_res          = 480,
+
+        .pixel_clock    = 23500,
+
+        .hfp            = 48,
+        .hsw            = 32,
+        .hbp            = 80,
+
+        .vfp            = 3,
+        .vsw            = 4,
+        .vbp            = 7,
+};
+
+struct panel_drv_data {
+        struct omap_dss_device *dssdev;
+
+        struct mutex lock;
+};
+
+static inline struct panel_dvi_platform_data
+*get_pdata(const struct omap_dss_device *dssdev)
+{
+        return dssdev->data;
+}
+
+static int panel_dvi_power_on(struct omap_dss_device *dssdev)
+{
+        struct panel_dvi_platform_data *pdata = get_pdata(dssdev);
+        int r;
+
+        if (dssdev->state == OMAP_DSS_DISPLAY_ACTIVE)
+                return 0;
+
+        r = omapdss_dpi_display_enable(dssdev);
+        if (r)
+                goto err0;
+
+        if (pdata->platform_enable) {
+                r = pdata->platform_enable(dssdev);
+                if (r)
+                        goto err1;
+        }
+
+        return 0;
+err1:
+        omapdss_dpi_display_disable(dssdev);
+err0:
+        return r;
+}
+
+static void panel_dvi_power_off(struct omap_dss_device *dssdev)
+{
+        struct panel_dvi_platform_data *pdata = get_pdata(dssdev);
+
+        if (dssdev->state != OMAP_DSS_DISPLAY_ACTIVE)
+                return;
+
+        if (pdata->platform_disable)
+                pdata->platform_disable(dssdev);
+
+        omapdss_dpi_display_disable(dssdev);
+}
+
+static int panel_dvi_probe(struct omap_dss_device *dssdev)
+{
+        struct panel_drv_data *ddata;
+
+        ddata = kzalloc(sizeof(*ddata), GFP_KERNEL);
+        if (!ddata)
+                return -ENOMEM;
+
+        dssdev->panel.timings = panel_dvi_default_timings;
+        dssdev->panel.config = OMAP_DSS_LCD_TFT;
+
+        ddata->dssdev = dssdev;
+        mutex_init(&ddata->lock);
+
+        dev_set_drvdata(&dssdev->dev, ddata);
+
+        return 0;
+}
+
+static void __exit panel_dvi_remove(struct omap_dss_device *dssdev)
+{
+        struct panel_drv_data *ddata = dev_get_drvdata(&dssdev->dev);
+
+        mutex_lock(&ddata->lock);
+
+        dev_set_drvdata(&dssdev->dev, NULL);
+
+        mutex_unlock(&ddata->lock);
+
+        kfree(ddata);
+}
+
+static int panel_dvi_enable(struct omap_dss_device *dssdev)
+{
+        struct panel_drv_data *ddata = dev_get_drvdata(&dssdev->dev);
+        int r;
+
+        mutex_lock(&ddata->lock);
+
+        r = panel_dvi_power_on(dssdev);
+        if (r == 0)
+                dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
+
+        mutex_unlock(&ddata->lock);
+
+        return r;
+}
+
+static void panel_dvi_disable(struct omap_dss_device *dssdev)
+{
+        struct panel_drv_data *ddata = dev_get_drvdata(&dssdev->dev);
+
+        mutex_lock(&ddata->lock);
+
+        panel_dvi_power_off(dssdev);
+
+        dssdev->state = OMAP_DSS_DISPLAY_DISABLED;
+
+        mutex_unlock(&ddata->lock);
+}
+
+static int panel_dvi_suspend(struct omap_dss_device *dssdev)
+{
+        struct panel_drv_data *ddata = dev_get_drvdata(&dssdev->dev);
+
+        mutex_lock(&ddata->lock);
+
+        panel_dvi_power_off(dssdev);
+
+        dssdev->state = OMAP_DSS_DISPLAY_SUSPENDED;
+
+        mutex_unlock(&ddata->lock);
+
+        return 0;
+}
+
+static int panel_dvi_resume(struct omap_dss_device *dssdev)
+{
+        struct panel_drv_data *ddata = dev_get_drvdata(&dssdev->dev);
+        int r;
+
+        mutex_lock(&ddata->lock);
+
+        r = panel_dvi_power_on(dssdev);
+        if (r == 0)
+                dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
+
+        mutex_unlock(&ddata->lock);
+
+        return r;
+}
+
+static void panel_dvi_set_timings(struct omap_dss_device *dssdev,
+                struct omap_video_timings *timings)
+{
+        struct panel_drv_data *ddata = dev_get_drvdata(&dssdev->dev);
+
+        mutex_lock(&ddata->lock);
+        dpi_set_timings(dssdev, timings);
+        mutex_unlock(&ddata->lock);
+}
+
+static void panel_dvi_get_timings(struct omap_dss_device *dssdev,
+                struct omap_video_timings *timings)
+{
+        struct panel_drv_data *ddata = dev_get_drvdata(&dssdev->dev);
+
+        mutex_lock(&ddata->lock);
+        *timings = dssdev->panel.timings;
+        mutex_unlock(&ddata->lock);
+}
+
+static int panel_dvi_check_timings(struct omap_dss_device *dssdev,
+                struct omap_video_timings *timings)
+{
+        struct panel_drv_data *ddata = dev_get_drvdata(&dssdev->dev);
+        int r;
+
+        mutex_lock(&ddata->lock);
+        r = dpi_check_timings(dssdev, timings);
+        mutex_unlock(&ddata->lock);
+
+        return r;
+}
+
+
+static int panel_dvi_ddc_read(struct i2c_adapter *adapter,
+                unsigned char *buf, u16 count, u8 offset)
+{
+        int r, retries;
+
+        for (retries = 3; retries > 0; retries--) {
+                struct i2c_msg msgs[] = {
+                        {
+                                .addr   = DDC_ADDR,
+                                .flags  = 0,
+                                .len    = 1,
+                                .buf    = &offset,
+                        }, {
+                                .addr   = DDC_ADDR,
+                                .flags  = I2C_M_RD,
+                                .len    = count,
+                                .buf    = buf,
+                        }
+                };
+
+                r = i2c_transfer(adapter, msgs, 2);
+                if (r == 2)
+                        return 0;
+
+                if (r != -EAGAIN)
+                        break;
+        }
+
+        return r < 0 ? r : -EIO;
+}
+
+static int panel_dvi_read_edid(struct omap_dss_device *dssdev,
+                u8 *edid, int len)
+{
+        struct panel_drv_data *ddata = dev_get_drvdata(&dssdev->dev);
+        struct panel_dvi_platform_data *pdata = get_pdata(dssdev);
+        struct i2c_adapter *adapter;
+        int r, l, bytes_read;
+
+        mutex_lock(&ddata->lock);
+
+        if (pdata->i2c_bus_num == 0) {
+                r = -ENODEV;
+                goto err;
+        }
+
+        adapter = i2c_get_adapter(pdata->i2c_bus_num);
+        if (!adapter) {
+                dev_err(&dssdev->dev, "Failed to get I2C adapter, bus %d\n",
+                                pdata->i2c_bus_num);
+                r = -EINVAL;
+                goto err;
+        }
+
+        l = min(EDID_LENGTH, len);
+        r = panel_dvi_ddc_read(adapter, edid, l, 0);
+        if (r)
+                goto err;
+
+        bytes_read = l;
+
+        /* if there are extensions, read second block */
+        if (len > EDID_LENGTH && edid[0x7e] > 0) {
+                l = min(EDID_LENGTH, len - EDID_LENGTH);
+
+                r = panel_dvi_ddc_read(adapter, edid + EDID_LENGTH,
+                                l, EDID_LENGTH);
+                if (r)
+                        goto err;
+
+                bytes_read += l;
+        }
+
+        mutex_unlock(&ddata->lock);
+
+        return bytes_read;
+
+err:
+        mutex_unlock(&ddata->lock);
+        return r;
+}
+
+static bool panel_dvi_detect(struct omap_dss_device *dssdev)
+{
+        struct panel_drv_data *ddata = dev_get_drvdata(&dssdev->dev);
+        struct panel_dvi_platform_data *pdata = get_pdata(dssdev);
+        struct i2c_adapter *adapter;
+        unsigned char out;
+        int r;
+
+        mutex_lock(&ddata->lock);
+
+        if (pdata->i2c_bus_num == 0)
+                goto out;
+
+        adapter = i2c_get_adapter(pdata->i2c_bus_num);
+        if (!adapter)
+                goto out;
+
+        r = panel_dvi_ddc_read(adapter, &out, 1, 0);
+
+        mutex_unlock(&ddata->lock);
+
+        return r == 0;
+
+out:
+        mutex_unlock(&ddata->lock);
+        return true;
+}
+
+static struct omap_dss_driver panel_dvi_driver = {
+        .probe          = panel_dvi_probe,
+        .remove         = __exit_p(panel_dvi_remove),
+
+        .enable         = panel_dvi_enable,
+        .disable        = panel_dvi_disable,
+        .suspend        = panel_dvi_suspend,
+        .resume         = panel_dvi_resume,
+
+        .set_timings    = panel_dvi_set_timings,
+        .get_timings    = panel_dvi_get_timings,
+        .check_timings  = panel_dvi_check_timings,
+
+        .read_edid      = panel_dvi_read_edid,
+        .detect         = panel_dvi_detect,
+
+        .driver         = {
+                .name   = "dvi",
+                .owner  = THIS_MODULE,
+        },
+};
+
+static int __init panel_dvi_init(void)
+{
+        return omap_dss_register_driver(&panel_dvi_driver);
+}
+
+static void __exit panel_dvi_exit(void)
+{
+        omap_dss_unregister_driver(&panel_dvi_driver);
+}
+
+module_init(panel_dvi_init);
+module_exit(panel_dvi_exit);
+MODULE_LICENSE("GPL");