drm/bridge: Add I2C based driver for ps8622/ps8625 bridge

This patch adds drm_bridge driver for parade DisplayPort
to LVDS bridge chip.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
Acked-by: Inki Dae <inki.dae@samsung.com>
Tested-by: Rahul Sharma <rahul.sharma@samsung.com>
Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Tested-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
[treding@nvidia.com: break cyclic dependency, add KMS helper dependency]
Signed-off-by: Thierry Reding <treding@nvidia.com>

3 files changed, 696 insertions, 0 deletions

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index f38bbcdf929b..acef3223772c 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -11,3 +11,14 @@ config DRM_PTN3460
         select DRM_PANEL
         ---help---
           ptn3460 eDP-LVDS bridge chip driver.
+
+config DRM_PS8622
+        tristate "Parade eDP/LVDS bridge"
+        depends on DRM
+        depends on OF
+        select DRM_PANEL
+        select DRM_KMS_HELPER
+        select BACKLIGHT_LCD_SUPPORT
+        select BACKLIGHT_CLASS_DEVICE
+        ---help---
+          parade eDP-LVDS bridge chip driver.
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index d8a8cfd12fbb..8dfebd984370 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -1,4 +1,5 @@
 ccflags-y := -Iinclude/drm
 
+obj-$(CONFIG_DRM_PS8622) += ps8622.o
 obj-$(CONFIG_DRM_PTN3460) += ptn3460.o
 obj-$(CONFIG_DRM_DW_HDMI) += dw_hdmi.o
diff --git a/drivers/gpu/drm/bridge/ps8622.c b/drivers/gpu/drm/bridge/ps8622.c
new file mode 100644
index 000000000000..5474a3957dc5
--- /dev/null
+++ b/drivers/gpu/drm/bridge/ps8622.c
@@ -0,0 +1,684 @@
+/*
+ * Parade PS8622 eDP/LVDS bridge driver
+ *
+ * Copyright (C) 2014 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ */
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/fb.h>
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_graph.h>
+#include <linux/pm.h>
+#include <linux/regulator/consumer.h>
+
+#include <drm/drm_panel.h>
+
+#include "drmP.h"
+#include "drm_crtc.h"
+#include "drm_crtc_helper.h"
+
+/* Brightness scale on the Parade chip */
+#define PS8622_MAX_BRIGHTNESS 0xff
+
+/* Timings taken from the version 1.7 datasheet for the PS8622/PS8625 */
+#define PS8622_POWER_RISE_T1_MIN_US 10
+#define PS8622_POWER_RISE_T1_MAX_US 10000
+#define PS8622_RST_HIGH_T2_MIN_US 3000
+#define PS8622_RST_HIGH_T2_MAX_US 30000
+#define PS8622_PWMO_END_T12_MS 200
+#define PS8622_POWER_FALL_T16_MAX_US 10000
+#define PS8622_POWER_OFF_T17_MS 500
+
+#if ((PS8622_RST_HIGH_T2_MIN_US + PS8622_POWER_RISE_T1_MAX_US) > \
+        (PS8622_RST_HIGH_T2_MAX_US + PS8622_POWER_RISE_T1_MIN_US))
+#error "T2.min + T1.max must be less than T2.max + T1.min"
+#endif
+
+struct ps8622_bridge {
+        struct drm_connector connector;
+        struct i2c_client *client;
+        struct drm_bridge bridge;
+        struct drm_panel *panel;
+        struct regulator *v12;
+        struct backlight_device *bl;
+
+        struct gpio_desc *gpio_slp;
+        struct gpio_desc *gpio_rst;
+
+        u32 max_lane_count;
+        u32 lane_count;
+
+        bool enabled;
+};
+
+static inline struct ps8622_bridge *
+                bridge_to_ps8622(struct drm_bridge *bridge)
+{
+        return container_of(bridge, struct ps8622_bridge, bridge);
+}
+
+static inline struct ps8622_bridge *
+                connector_to_ps8622(struct drm_connector *connector)
+{
+        return container_of(connector, struct ps8622_bridge, connector);
+}
+
+static int ps8622_set(struct i2c_client *client, u8 page, u8 reg, u8 val)
+{
+        int ret;
+        struct i2c_adapter *adap = client->adapter;
+        struct i2c_msg msg;
+        u8 data[] = {reg, val};
+
+        msg.addr = client->addr + page;
+        msg.flags = 0;
+        msg.len = sizeof(data);
+        msg.buf = data;
+
+        ret = i2c_transfer(adap, &msg, 1);
+        if (ret != 1)
+                pr_warn("PS8622 I2C write (0x%02x,0x%02x,0x%02x) failed: %d\n",
+                        client->addr + page, reg, val, ret);
+        return !(ret == 1);
+}
+
+static int ps8622_send_config(struct ps8622_bridge *ps8622)
+{
+        struct i2c_client *cl = ps8622->client;
+        int err = 0;
+
+        /* HPD low */
+        err = ps8622_set(cl, 0x02, 0xa1, 0x01);
+        if (err)
+                goto error;
+
+        /* SW setting: [1:0] SW output 1.2V voltage is lower to 96% */
+        err = ps8622_set(cl, 0x04, 0x14, 0x01);
+        if (err)
+                goto error;
+
+        /* RCO SS setting: [5:4] = b01 0.5%, b10 1%, b11 1.5% */
+        err = ps8622_set(cl, 0x04, 0xe3, 0x20);
+        if (err)
+                goto error;
+
+        /* [7] RCO SS enable */
+        err = ps8622_set(cl, 0x04, 0xe2, 0x80);
+        if (err)
+                goto error;
+
+        /* RPHY Setting
+         * [3:2] CDR tune wait cycle before measure for fine tune
+         * b00: 1us b01: 0.5us b10:2us, b11: 4us
+         */
+        err = ps8622_set(cl, 0x04, 0x8a, 0x0c);
+        if (err)
+                goto error;
+
+        /* [3] RFD always on */
+        err = ps8622_set(cl, 0x04, 0x89, 0x08);
+        if (err)
+                goto error;
+
+        /* CTN lock in/out: 20000ppm/80000ppm. Lock out 2 times. */
+        err = ps8622_set(cl, 0x04, 0x71, 0x2d);
+        if (err)
+                goto error;
+
+        /* 2.7G CDR settings: NOF=40LSB for HBR CDR  setting */
+        err = ps8622_set(cl, 0x04, 0x7d, 0x07);
+        if (err)
+                goto error;
+
+        /* [1:0] Fmin=+4bands */
+        err = ps8622_set(cl, 0x04, 0x7b, 0x00);
+        if (err)
+                goto error;
+
+        /* [7:5] DCO_FTRNG=+-40% */
+        err = ps8622_set(cl, 0x04, 0x7a, 0xfd);
+        if (err)
+                goto error;
+
+        /* 1.62G CDR settings: [5:2]NOF=64LSB [1:0]DCO scale is 2/5 */
+        err = ps8622_set(cl, 0x04, 0xc0, 0x12);
+        if (err)
+                goto error;