Message-Id: <1452079551-30914-1-git-send-email-boris.brezillon@free-electrons.com>
Date:	Wed,  6 Jan 2016 12:25:50 +0100
From:	Boris Brezillon <boris.brezillon@...e-electrons.com>
To:	David Airlie <airlied@...ux.ie>, Daniel Vetter <daniel@...ll.ch>,
	dri-devel@...ts.freedesktop.org
Cc:	Rob Herring <robh+dt@...nel.org>, Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>, devicetree@...r.kernel.org,
	Nicolas Ferre <nicolas.ferre@...el.com>,
	Jean-Christophe Plagniol-Villard <plagnioj@...osoft.com>,
	Alexandre Belloni <alexandre.belloni@...e-electrons.com>,
	linux-kernel@...r.kernel.org,
	Boris Brezillon <boris.brezillon@...e-electrons.com>
Subject: [PATCH 1/2] drm: bridge: sil902x

Add basic support for the sil902x RGB -> HDMI bridge.
This driver does not support audio output yet.

Signed-off-by: Boris Brezillon <boris.brezillon@...e-electrons.com>
---
Hello,

This patch is only adding basic support for the sil9022 chip.
As stated in the commit log, there's no audio support, but the
driver also hardcodes a lot of things (like the RGB input format to
use).
There are two reasons for this:
1/ the DRM framework does not allow for advanced link description
   between an encoder and a bridge (that's for the RGB format
   limitation). Any idea how this should be described?

2/ I don't have the datasheet of this HDMI encoder, and all logic
   has been extracted from those two drivers [1][2], which means
   I may miss some important things in my encoder setup.

Another thing I find weird in the drm_bridge interface is the fact
that we have a ->attach() method, but no ->detach(), which can be
a problem if we allow drm bridges and KMS drivers to be compiled as
modules. Any reason for that?

That's all for the questions part :-).

Best Regards,

Boris
---
 drivers/gpu/drm/bridge/Kconfig   |   8 +
 drivers/gpu/drm/bridge/Makefile  |   1 +
 drivers/gpu/drm/bridge/sil902x.c | 491 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 500 insertions(+)
 create mode 100644 drivers/gpu/drm/bridge/sil902x.c

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index 27e2022..9701fd2 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -40,4 +40,12 @@ config DRM_PARADE_PS8622
 	---help---
 	  Parade eDP-LVDS bridge chip driver.
 
+config DRM_SIL902X
+	tristate "Silicon Image sil902x RGB/HDMI bridge"
+	depends on OF
+	select DRM_KMS_HELPER
+	select REGMAP_I2C
+	---help---
+	  Silicon Image sil902x bridge chip driver.
+
 endmenu
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index f13c33d..a689aad 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
 obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o
 obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
 obj-$(CONFIG_DRM_PARADE_PS8622) += parade-ps8622.o
+obj-$(CONFIG_DRM_SIL902X) += sil902x.o
diff --git a/drivers/gpu/drm/bridge/sil902x.c b/drivers/gpu/drm/bridge/sil902x.c
new file mode 100644
index 0000000..230732d
--- /dev/null
+++ b/drivers/gpu/drm/bridge/sil902x.c
@@ -0,0 +1,491 @@
+/*
+ * Copyright (C) 2014 Atmel
+ *		      Bo Shen <voice.shen@...el.com>
+ *
+ * Authors:	      Bo Shen <voice.shen@...el.com>
+ *		      Boris Brezillon <boris.brezillon@...e-electrons.com>
+ *		      Wu, Songjun <Songjun.Wu@...el.com>
+ *
+ *
+ * Copyright (C) 2010-2011 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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/component.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/regmap.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_edid.h>
+#include <drm/drm_encoder_slave.h>
+
+#define SIL902X_TPI_VIDEO_DATA			0x0
+
+#define SIL902X_TPI_PIXEL_REPETITION		0x8
+#define SIL902X_TPI_AVI_PIXEL_REP_BUS_24BIT     BIT(5)
+#define SIL902X_TPI_AVI_PIXEL_REP_RISING_EDGE   BIT(4)
+#define SIL902X_TPI_AVI_PIXEL_REP_4X		3
+#define SIL902X_TPI_AVI_PIXEL_REP_2X		1
+#define SIL902X_TPI_AVI_PIXEL_REP_NONE		0
+#define SIL902X_TPI_CLK_RATIO_HALF		(0 << 6)
+#define SIL902X_TPI_CLK_RATIO_1X		(1 << 6)
+#define SIL902X_TPI_CLK_RATIO_2X		(2 << 6)
+#define SIL902X_TPI_CLK_RATIO_4X		(3 << 6)
+
+#define SIL902X_TPI_AVI_IN_FORMAT		0x9
+#define SIL902X_TPI_AVI_INPUT_BITMODE_12BIT	BIT(7)
+#define SIL902X_TPI_AVI_INPUT_DITHER		BIT(6)
+#define SIL902X_TPI_AVI_INPUT_RANGE_LIMITED	(2 << 2)
+#define SIL902X_TPI_AVI_INPUT_RANGE_FULL	(1 << 2)
+#define SIL902X_TPI_AVI_INPUT_RANGE_AUTO	(0 << 2)
+#define SIL902X_TPI_AVI_INPUT_COLORSPACE_BLACK	(3 << 0)
+#define SIL902X_TPI_AVI_INPUT_COLORSPACE_YUV422	(2 << 0)
+#define SIL902X_TPI_AVI_INPUT_COLORSPACE_YUV444	(1 << 0)
+#define SIL902X_TPI_AVI_INPUT_COLORSPACE_RGB	(0 << 0)
+
+#define SIL902X_TPI_AVI_INFOFRAME		0x0c
+
+#define SIL902X_SYS_CTRL_DATA			0x1a
+#define SIL902X_SYS_CTRL_PWR_DWN		BIT(4)
+#define SIL902X_SYS_CTRL_AV_MUTE		BIT(3)
+#define SIL902X_SYS_CTRL_DDC_BUS_REQ		BIT(2)
+#define SIL902X_SYS_CTRL_DDC_BUS_GRTD		BIT(1)
+#define SIL902X_SYS_CTRL_OUTPUT_MODE		BIT(0)
+#define SIL902X_SYS_CTRL_OUTPUT_HDMI		1
+#define SIL902X_SYS_CTRL_OUTPUT_DVI		0
+
+#define SIL902X_REG_CHIPID(n)			(0x1b + (n))
+
+#define SIL902X_PWR_STATE_CTRL			0x1e
+#define SIL902X_AVI_POWER_STATE_MSK		GENMASK(1, 0)
+#define SIL902X_AVI_POWER_STATE_D(l)		((l) & SIL902X_AVI_POWER_STATE_MSK)
+
+#define SI902X_INT_ENABLE			0x3c
+#define SI902X_INT_STATUS			0x3d
+#define SI902X_HOTPLUG_EVENT			BIT(0)
+#define SI902X_PLUGGED_STATUS			BIT(2)
+
+#define SIL902X_REG_TPI_RQB			0xc7
+
+struct sil902x {
+	struct i2c_client *i2c;
+	struct regmap *regmap;
+	struct drm_bridge bridge;
+	struct drm_connector connector;
+	struct gpio_desc *reset_gpio;
+	struct work_struct hotplug_work;
+};
+
+static inline struct sil902x *bridge_to_sil902x(struct drm_bridge *bridge)
+{
+	return container_of(bridge, struct sil902x, bridge);
+}
+
+static inline struct sil902x *connector_to_sil902x(struct drm_connector *con)
+{
+	return container_of(con, struct sil902x, connector);
+}
+
+static void sil902x_reset(struct sil902x *sil902x)
+{
+	gpiod_set_value(sil902x->reset_gpio, 1);
+
+	msleep(100);
+
+	gpiod_set_value(sil902x->reset_gpio, 0);
+}
+
+static void sil902x_connector_destroy(struct drm_connector *connector)
+{
+	drm_connector_unregister(connector);
+	drm_connector_cleanup(connector);
+}
+
+static enum drm_connector_status
+sil902x_connector_detect(struct drm_connector *connector, bool force)
+{
+	struct sil902x *sil902x = connector_to_sil902x(connector);
+	unsigned int status;
+
+	regmap_read(sil902x->regmap, SI902X_INT_STATUS, &status);
+
+	return (status & SI902X_PLUGGED_STATUS) ?
+	       connector_status_connected : connector_status_disconnected;
+}
+
+static const struct drm_connector_funcs sil902x_atomic_connector_funcs = {
+	.dpms = drm_atomic_helper_connector_dpms,
+	.detect = sil902x_connector_detect,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.destroy = sil902x_connector_destroy,
+	.reset = drm_atomic_helper_connector_reset,
+	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static const struct drm_connector_funcs sil902x_connector_funcs = {
+	.dpms = drm_atomic_helper_connector_dpms,
+	.detect = sil902x_connector_detect,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.destroy = sil902x_connector_destroy,
+};
+
+static int sil902x_get_modes(struct drm_connector *connector)
+{
+	struct sil902x *sil902x = connector_to_sil902x(connector);
+	struct regmap *regmap = sil902x->regmap;
+	u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
+	unsigned int status;
+	struct edid *edid;
+	int num = 0;
+	int ret;
+	int i;
+
+	ret = regmap_update_bits(regmap, SIL902X_PWR_STATE_CTRL,
+				 SIL902X_AVI_POWER_STATE_MSK,
+				 SIL902X_AVI_POWER_STATE_D(2));
+	if (ret)
+		return ret;
+
+	ret = regmap_write(regmap, SIL902X_SYS_CTRL_DATA,
+			   SIL902X_SYS_CTRL_OUTPUT_HDMI |
+			   SIL902X_SYS_CTRL_PWR_DWN);
+	if (ret)
+		return ret;
+
+	ret = regmap_update_bits(regmap, SIL902X_SYS_CTRL_DATA,
+				 SIL902X_SYS_CTRL_DDC_BUS_REQ,
+				 SIL902X_SYS_CTRL_DDC_BUS_REQ);
+	if (ret)
+		return ret;
+
+	i = 0;
+	do {
+		ret = regmap_read(regmap, SIL902X_SYS_CTRL_DATA, &status);
+		if (ret)
+			return ret;
+		i++;
+	} while (!(status & SIL902X_SYS_CTRL_DDC_BUS_GRTD));
+
+	ret = regmap_write(regmap, SIL902X_SYS_CTRL_DATA, status);
+	if (ret)
+		return ret;
+
+	edid = drm_get_edid(connector, sil902x->i2c->adapter);
+	drm_mode_connector_update_edid_property(connector, edid);
+	if (edid) {
+		num += drm_add_edid_modes(connector, edid);
+		kfree(edid);
+	}
+
+	ret = drm_display_info_set_bus_formats(&connector->display_info,
+					       &bus_format, 1);
+	if (ret)
+		return ret;
+
+	regmap_read(regmap, SIL902X_SYS_CTRL_DATA, &status);
+	if (ret)
+		return ret;
+
+	ret = regmap_update_bits(regmap, SIL902X_SYS_CTRL_DATA,
+				 SIL902X_SYS_CTRL_DDC_BUS_REQ |
+				 SIL902X_SYS_CTRL_DDC_BUS_GRTD, 0);
+	if (ret)
+		return ret;
+
+	i = 0;
+	do {
+		ret = regmap_read(regmap, SIL902X_SYS_CTRL_DATA, &status);
+		if (ret)
+			return ret;
+		i++;
+	} while (status & (SIL902X_SYS_CTRL_DDC_BUS_REQ |
+			   SIL902X_SYS_CTRL_DDC_BUS_GRTD));
+
+	return num;
+}
+
+static enum drm_mode_status sil902x_mode_valid(struct drm_connector *connector,
+					       struct drm_display_mode *mode)
+{
+	/* TODO: check mode */
+
+	return MODE_OK;
+}
+
+static struct drm_encoder *sil902x_best_encoder(struct drm_connector *connector)
+{
+	struct sil902x *sil902x = connector_to_sil902x(connector);
+
+	return sil902x->bridge.encoder;
+}
+
+static const struct drm_connector_helper_funcs sil902x_connector_helper_funcs = {
+	.get_modes = sil902x_get_modes,
+	.mode_valid = sil902x_mode_valid,
+	.best_encoder = sil902x_best_encoder,
+};
+
+static void sil902x_bridge_disable(struct drm_bridge *bridge)
+{
+	struct sil902x *sil902x = bridge_to_sil902x(bridge);
+
+	regmap_update_bits(sil902x->regmap, SIL902X_SYS_CTRL_DATA,
+			   SIL902X_SYS_CTRL_PWR_DWN,
+			   SIL902X_SYS_CTRL_PWR_DWN);
+}
+
+static void sil902x_bridge_enable(struct drm_bridge *bridge)
+{
+	struct sil902x *sil902x = bridge_to_sil902x(bridge);
+
+	regmap_update_bits(sil902x->regmap, SIL902X_PWR_STATE_CTRL,
+			   SIL902X_AVI_POWER_STATE_MSK,
+			   SIL902X_AVI_POWER_STATE_D(0));
+	regmap_update_bits(sil902x->regmap, SIL902X_SYS_CTRL_DATA,
+			   SIL902X_SYS_CTRL_PWR_DWN, 0);
+}
+
+static void sil902x_bridge_mode_set(struct drm_bridge *bridge,
+				    struct drm_display_mode *mode,
+				    struct drm_display_mode *adj)
+{
+	u8 buf[HDMI_INFOFRAME_HEADER_SIZE + HDMI_AVI_INFOFRAME_SIZE];
+	struct sil902x *sil902x = bridge_to_sil902x(bridge);
+	struct regmap *regmap = sil902x->regmap;
+	struct hdmi_avi_infoframe frame;
+	int ret;
+
+	buf[0] = adj->clock;
+	buf[1] = adj->clock >> 8;
+	buf[2] = adj->vrefresh;
+	buf[3] = 0x00;
+	buf[4] = adj->hdisplay;
+	buf[5] = adj->hdisplay >> 8;
+	buf[6] = adj->vdisplay;
+	buf[7] = adj->vdisplay >> 8;
+	buf[8] = SIL902X_TPI_CLK_RATIO_1X | SIL902X_TPI_AVI_PIXEL_REP_NONE |
+		 SIL902X_TPI_AVI_PIXEL_REP_BUS_24BIT;
+	buf[9] = SIL902X_TPI_AVI_INPUT_RANGE_AUTO |
+		 SIL902X_TPI_AVI_INPUT_COLORSPACE_RGB;
+
+	ret = regmap_bulk_write(regmap, SIL902X_TPI_VIDEO_DATA, buf, 10);
+	if (ret)
+		return;
+
+	ret = drm_hdmi_avi_infoframe_from_display_mode(&frame, adj);
+	if (ret < 0) {
+		DRM_ERROR("couldn't fill AVI infoframe\n");
+		return;
+	}
+
+	ret = hdmi_avi_infoframe_pack(&frame, buf, sizeof(buf));
+	if (ret < 0) {
+		DRM_ERROR("failed to pack AVI infoframe: %zd\n", ret);
+		return;
+	}
+
+	/* Do not send the infoframe header, but keep the CRC field. */
+	regmap_bulk_write(regmap, SIL902X_TPI_AVI_INFOFRAME,
+			  buf + HDMI_INFOFRAME_HEADER_SIZE - 1,
+			  HDMI_AVI_INFOFRAME_SIZE + 1);
+}
+
+static int sil902x_bridge_attach(struct drm_bridge *bridge)
+{
+	const struct drm_connector_funcs *funcs = &sil902x_connector_funcs;
+	struct sil902x *sil902x = bridge_to_sil902x(bridge);
+	struct drm_device *drm = bridge->dev;
+	int ret;
+
+	drm_connector_helper_add(&sil902x->connector,
+				 &sil902x_connector_helper_funcs);
+
+	if (drm_core_check_feature(drm, DRIVER_ATOMIC))
+		funcs = &sil902x_atomic_connector_funcs;
+
+	ret = drm_connector_init(drm, &sil902x->connector, funcs,
+				 DRM_MODE_CONNECTOR_HDMIA);
+	if (ret)
+		return ret;
+
+	if (sil902x->i2c->irq > 0)
+		sil902x->connector.polled = DRM_CONNECTOR_POLL_HPD;
+	else
+		sil902x->connector.polled = DRM_CONNECTOR_POLL_CONNECT;
+
+	drm_mode_connector_attach_encoder(&sil902x->connector, bridge->encoder);
+
+	return 0;
+}
+
+static void sil902x_bridge_nop(struct drm_bridge *bridge)
+{
+}
+
+static const struct drm_bridge_funcs sil902x_bridge_funcs = {
+	.attach = sil902x_bridge_attach,
+	.mode_set = sil902x_bridge_mode_set,
+	.disable = sil902x_bridge_disable,
+	.post_disable = sil902x_bridge_nop,
+	.pre_enable = sil902x_bridge_nop,
+	.enable = sil902x_bridge_enable,
+};
+
+static const struct regmap_range sil902x_volatile_ranges[] = {
+	{ .range_min = 0, .range_max = 0xff },
+};
+
+static const struct regmap_access_table sil902x_volatile_table = {
+	.yes_ranges = sil902x_volatile_ranges,
+	.n_yes_ranges = ARRAY_SIZE(sil902x_volatile_ranges),
+};
+
+static const struct regmap_config sil902x_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.volatile_table = &sil902x_volatile_table,
+	.cache_type = REGCACHE_NONE,
+};
+
+static irqreturn_t sil902x_interrupt(int irq, void *data)
+{
+	struct sil902x *sil902x = data;
+	unsigned int status = 0;
+
+	regmap_read(sil902x->regmap, SI902X_INT_STATUS, &status);
+	regmap_write(sil902x->regmap, SI902X_INT_STATUS, status);
+
+	if ((status & SI902X_HOTPLUG_EVENT) && sil902x->bridge.dev)
+		drm_helper_hpd_irq_event(sil902x->bridge.dev);
+
+	return IRQ_HANDLED;
+}
+
+static int sil902x_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	unsigned int status = 0;
+	struct sil902x *sil902x;
+	u8 chipid[4];
+	int ret;
+
+	sil902x = devm_kzalloc(dev, sizeof(*sil902x), GFP_KERNEL);
+	if (!sil902x)
+		return -ENOMEM;
+
+	sil902x->i2c = client;
+	sil902x->regmap = devm_regmap_init_i2c(client, &sil902x_regmap_config);
+	if (IS_ERR(sil902x->regmap))
+		return PTR_ERR(sil902x->regmap);
+
+	sil902x->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(sil902x->reset_gpio)) {
+		dev_err(dev, "Failed to retrieve/request reset gpio: %d\n",
+			PTR_ERR(sil902x->reset_gpio));
+		return PTR_ERR(sil902x->reset_gpio);
+	}
+
+	sil902x_reset(sil902x);
+
+	ret = regmap_write(sil902x->regmap, SIL902X_REG_TPI_RQB, 0x0);
+	if (ret)
+		return ret;
+
+	ret = regmap_bulk_read(sil902x->regmap, SIL902X_REG_CHIPID(0),
+			       &chipid, 4);
+	if (ret) {
+		dev_err(dev, "regmap_read failed %d\n", ret);
+		return ret;
+	}
+
+	if (chipid[0] != 0xb0) {
+		dev_err(dev, "Invalid chipid: %02x (expecting 0xb0)\n",
+			chipid[0]);
+		return -EINVAL;
+	}
+
+	/* Clear all pending interrupts */
+	regmap_read(sil902x->regmap, SI902X_INT_STATUS, &status);
+	regmap_write(sil902x->regmap, SI902X_INT_STATUS, status);
+
+	if (client->irq > 0) {
+		regmap_write(sil902x->regmap, SI902X_INT_ENABLE,
+			     SI902X_HOTPLUG_EVENT);
+
+		ret = devm_request_threaded_irq(dev, client->irq, NULL,
+						sil902x_interrupt,
+						IRQF_ONESHOT, dev_name(dev),
+						sil902x);
+		if (ret)
+			return ret;
+	}
+
+	sil902x->bridge.funcs = &sil902x_bridge_funcs;
+	sil902x->bridge.of_node = dev->of_node;
+	ret = drm_bridge_add(&sil902x->bridge);
+	if (ret) {
+		dev_err(dev, "Failed to add drm_bridge\n");
+		return ret;
+	}
+
+	i2c_set_clientdata(client, sil902x);
+
+	return 0;
+}
+
+static int sil902x_remove(struct i2c_client *client)
+
+{
+	struct sil902x *sil902x = i2c_get_clientdata(client);
+
+	drm_bridge_remove(&sil902x->bridge);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id sil902x_dt_ids[] = {
+	{ .compatible = "sil,sil9022", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sil902x_dt_ids);
+#endif
+
+static const struct i2c_device_id sil902x_i2c_ids[] = {
+	{ "sil9022", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, sil9022_id);
+
+static struct i2c_driver sil902x_driver = {
+	.probe = sil902x_probe,
+	.remove = sil902x_remove,
+	.driver = {
+		.name = "sil902x",
+		.of_match_table = of_match_ptr(sil902x_dt_ids),
+	},
+	.id_table = sil902x_i2c_ids,
+};
+module_i2c_driver(sil902x_driver);
+
+MODULE_AUTHOR("Boris Brezillon <boris.brezillon@...e-electrons.com>");
+MODULE_DESCRIPTION("SIL902x RGB -> HDMI bridges");
+MODULE_LICENSE("GPL");
-- 
2.1.4

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