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From:   Enric Balletbo i Serra <enric.balletbo@collabora.com>
To:     linux-kernel@vger.kernel.org
Cc:     Collabora Kernel ML <kernel@collabora.com>, matthias.bgg@gmail.com,
        drinkcat@chromium.org, hsinyi@chromium.org,
        Jitao Shi <jitao.shi@mediatek.com>,
        Daniel Kurtz <djkurtz@chromium.org>,
        Ulrich Hecht <uli@fpond.eu>,
        linux-arm-kernel@lists.infradead.org,
        Andrzej Hajda <a.hajda@samsung.com>,
        Jonas Karlman <jonas@kwiboo.se>,
        dri-devel@lists.freedesktop.org,
        Neil Armstrong <narmstrong@baylibre.com>,
        linux-mediatek@lists.infradead.org,
        David Airlie <airlied@linux.ie>,
        Jernej Skrabec <jernej.skrabec@siol.net>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        Daniel Vetter <daniel@ffwll.ch>
Subject: [PATCH v22 2/2] drm/bridge: Add I2C based driver for ps8640 bridge
Date:   Fri, 20 Dec 2019 09:17:38 +0100
Message-Id: <20191220081738.1895-3-enric.balletbo@collabora.com>
In-Reply-To: <20191220081738.1895-1-enric.balletbo@collabora.com>
References: <20191220081738.1895-1-enric.balletbo@collabora.com>
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From: Jitao Shi <jitao.shi@mediatek.com>

This patch adds drm_bridge driver for parade DSI to eDP bridge chip.

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
[uli: followed API changes, removed FW update feature]
Signed-off-by: Ulrich Hecht <uli@fpond.eu>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
---
One of the reviews from Laurent was to use 'i2c_new_ancillary_device'. I
didn't change this for two reasons.
1) It doesn't have a devm version, so the remove path is more simple
using the devm_i2c_new_dummy_device family.
2) IIUC the ancillary function is useful when you want to retrieve the
address from the firmware or DT, that's not really the case here, as we
have a base address and fixed offset to the base address which I think
is not configurable.

Let me know if you still think that I should use the ancillary call.

Changes in v22:
- Remove sysfs attributes because are not really used (Enric Balletbo)
- Use enum for address page offsets (Ezequiel Garcia)
- Remove enable tracking (Enric Balletbo)
- Use panel_bridge API (Laurent Pinchart)
- Do not use kernel-doc format for non kernel-doc formatted commands (Enric Balletbo)
- Remove verbose message for PAGE1_VSTART command (Ezequiel Garcia)
- Use time_is_after_jiffies idiom (Ezequiel Garcia)
- Remove unused macros (Ezequiel Garcia)
- Fix weird alignment in dsi->mode_flags (Laurent Pinchart)
- Use drm_of_find_panel_or_bridge helper (Laurent Pinchart)
- Remove mode-sel-gpios as is not used (Laurent Pinchart)
- Remove error messages to get gpios as the core will already report it (Enric Balletbo)
- Remove redundant message getting the regulators (Laurent Pinchart)
- Rename sleep-gpios to powerdown-gpios (Laurent Pinchart)
- Use ARRAY_SIZE(ps_bridge->page) instead of MAX_DEV when possible (Laurent Pinchart)
- Fix race with userspace accessing the sysfs attributes (Laurent Pinchart)
- Remove id_table as is only used on DR platforms (Laurent Pinchart)
- Convert to new i2c device probe() (Laurent Pinchart)
- Use i2c_smbus_read/write helpers instead of open coding it (Laurent Pinchart)
- Remove unnused global variables (Laurent Pinchart)
- Remove unnused fields in ps8640 struct (Laurent Pinchart)
- Remove commented-out headers (Laurent Pinchart)

Changes in v21:
 - Use devm_i2c_new_dummy_device and fix build issue using deprecated i2c_new_dummy
 - Fix build issue due missing drm_bridge.h
 - Do not remove in ps8640_remove device managed resources

Changes in v19:
 - fixed return value of ps8640_probe() when no panel is found

Changes in v18:
 - followed DRM API changes
 - use DEVICE_ATTR_RO()
 - remove firmware update code
 - add SPDX identifier

Changes in v17:
 - remove some unused head files.
 - add macros for ps8640 pages.
 - remove ddc_i2c client
 - add mipi_dsi_device_register_full
 - remove the manufacturer from the name and i2c_device_id

Changes in v16:
 - Disable ps8640 DSI MCS Function.
 - Rename gpios name more clearly.
 - Tune the ps8640 power on sequence.

Changes in v15:
 - Drop drm_connector_(un)register calls from parade ps8640.
   The main DRM driver mtk_drm_drv now calls
   drm_connector_register_all() after drm_dev_register() in the
   mtk_drm_bind() function. That function should iterate over all
   connectors and call drm_connector_register() for each of them.
   So, remove drm_connector_(un)register calls from parade ps8640.

Changes in v14:
 - update copyright info.
 - change bridge_to_ps8640 and connector_to_ps8640 to inline function.
 - fix some coding style.
 - use sizeof as array counter.
 - use drm_get_edid when read edid.
 - add mutex when firmware updating.

Changes in v13:
 - add const on data, ps8640_write_bytes(struct i2c_client *client, const u8 *data, u16 data_len)
 - fix PAGE2_SW_REST tyro.
 - move the buf[3] init to entrance of the function.

Changes in v12:
 - fix hw_chip_id build warning

Changes in v11:
 - Remove depends on I2C, add DRM depends
 - Reuse ps8640_write_bytes() in ps8640_write_byte()
 - Use timer check for polling like the routines in <linux/iopoll.h>
 - Fix no drm_connector_unregister/drm_connector_cleanup when ps8640_bridge_attach fail
 - Check the ps8640 hardware id in ps8640_validate_firmware
 - Remove fw_version check
 - Move ps8640_validate_firmware before ps8640_enter_bl
 - Add ddc_i2c unregister when probe fail and ps8640_remove

 drivers/gpu/drm/bridge/Kconfig         |  11 +
 drivers/gpu/drm/bridge/Makefile        |   1 +
 drivers/gpu/drm/bridge/parade-ps8640.c | 354 +++++++++++++++++++++++++
 3 files changed, 366 insertions(+)
 create mode 100644 drivers/gpu/drm/bridge/parade-ps8640.c

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index 4734f6993858..3e0a63011723 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -101,6 +101,17 @@ config DRM_PARADE_PS8622
 	---help---
 	  Parade eDP-LVDS bridge chip driver.
 
+config DRM_PARADE_PS8640
+	tristate "Parade PS8640 MIPI DSI to eDP Converter"
+	depends on OF
+	select DRM_KMS_HELPER
+	select DRM_MIPI_DSI
+	select DRM_PANEL
+	help
+	  Choose this option if you have PS8640 for display
+	  The PS8640 is a high-performance and low-power
+	  MIPI DSI to eDP converter
+
 config DRM_SIL_SII8620
 	tristate "Silicon Image SII8620 HDMI/MHL bridge"
 	depends on OF
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index 1c0c92667ac4..91490c595b38 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_DRM_LVDS_ENCODER) += lvds-encoder.o
 obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += megachips-stdpxxxx-ge-b850v3-fw.o
 obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
 obj-$(CONFIG_DRM_PARADE_PS8622) += parade-ps8622.o
+obj-$(CONFIG_DRM_PARADE_PS8640) += parade-ps8640.o
 obj-$(CONFIG_DRM_SIL_SII8620) += sil-sii8620.o
 obj-$(CONFIG_DRM_SII902X) += sii902x.o
 obj-$(CONFIG_DRM_SII9234) += sii9234.o
diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c
new file mode 100644
index 000000000000..aa0045037f44
--- /dev/null
+++ b/drivers/gpu/drm/bridge/parade-ps8640.c
@@ -0,0 +1,354 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2016 MediaTek Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of_graph.h>
+#include <linux/regulator/consumer.h>
+
+#include <drm/drm_bridge.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_of.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_print.h>
+
+#define PAGE2_GPIO_H		0xa7
+#define PS_GPIO9		BIT(1)
+#define PAGE2_I2C_BYPASS	0xea
+#define I2C_BYPASS_EN		0xd0
+#define PAGE2_MCS_EN		0xf3
+#define MCS_EN			BIT(0)
+#define PAGE3_SET_ADD		0xfe
+#define VDO_CTL_ADD		0x13
+#define VDO_DIS			0x18
+#define VDO_EN			0x1c
+
+/*
+ * PS8640 uses multiple addresses:
+ * page[0]: for DP control
+ * page[1]: for VIDEO Bridge
+ * page[2]: for control top
+ * page[3]: for DSI Link Control1
+ * page[4]: for MIPI Phy
+ * page[5]: for VPLL
+ * page[6]: for DSI Link Control2
+ * page[7]: for SPI ROM mapping
+ */
+enum page_addr_offset {
+	PAGE0_DP_CNTL = 0,
+	PAGE1_VDO_BDG,
+	PAGE2_TOP_CNTL,
+	PAGE3_DSI_CNTL1,
+	PAGE4_MIPI_PHY,
+	PAGE5_VPLL,
+	PAGE6_DSI_CNTL2,
+	PAGE7_SPI_CNTL,
+	MAX_DEVS
+};
+
+struct ps8640 {
+	struct drm_bridge bridge;
+	struct drm_bridge *panel_bridge;
+	struct mipi_dsi_device *dsi;
+	struct i2c_client *page[MAX_DEVS];
+	struct regulator_bulk_data supplies[2];
+	struct gpio_desc *gpio_reset;
+	struct gpio_desc *gpio_powerdown;
+};
+
+static inline struct ps8640 *bridge_to_ps8640(struct drm_bridge *e)
+{
+	return container_of(e, struct ps8640, bridge);
+}
+
+static int ps8640_bridge_unmute(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[PAGE3_DSI_CNTL1];
+	u8 vdo_ctrl_buf[] = { VDO_CTL_ADD, VDO_EN };
+	int ret;
+
+	ret = i2c_smbus_write_i2c_block_data(client, PAGE3_SET_ADD,
+					     sizeof(vdo_ctrl_buf),
+					     vdo_ctrl_buf);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int ps8640_bridge_mute(struct ps8640 *ps_bridge)
+{
+	struct i2c_client *client = ps_bridge->page[PAGE3_DSI_CNTL1];
+	u8 vdo_ctrl_buf[] = { VDO_CTL_ADD, VDO_DIS };
+	int ret;
+
+	ret = i2c_smbus_write_i2c_block_data(client, PAGE3_SET_ADD,
+					     sizeof(vdo_ctrl_buf),
+					     vdo_ctrl_buf);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static void ps8640_pre_enable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	struct i2c_client *client = ps_bridge->page[PAGE2_TOP_CNTL];
+	unsigned long timeout;
+	int ret, status;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(ps_bridge->supplies),
+				    ps_bridge->supplies);
+	if (ret < 0) {
+		DRM_ERROR("cannot enable regulators %d\n", ret);
+		return;
+	}
+
+	gpiod_set_value(ps_bridge->gpio_powerdown, 1);
+	gpiod_set_value(ps_bridge->gpio_reset, 0);
+	usleep_range(2000, 2500);
+	gpiod_set_value(ps_bridge->gpio_reset, 1);
+
+	/*
+	 * Wait for the ps8640 embedded MCU to be ready
+	 * First wait 200ms and then check the MCU ready flag every 20ms
+	 */
+	msleep(200);
+
+	timeout = jiffies + msecs_to_jiffies(200) + 1;
+
+	while (time_is_after_jiffies(timeout)) {
+		status = i2c_smbus_read_byte_data(client, PAGE2_GPIO_H);
+		if (status < 0) {
+			DRM_ERROR("failed read PAGE2_GPIO_H: %d\n", status);
+			goto err_regulators_disable;
+		}
+		if ((status & PS_GPIO9) == PS_GPIO9)
+			break;
+
+		msleep(20);
+	}
+
+	msleep(50);
+
+	/*
+	 * The Manufacturer Command Set (MCS) is a device dependent interface
+	 * intended for factory programming of the display module default
+	 * parameters. Once the display module is configured, the MCS shall be
+	 * disabled by the manufacturer. Once disabled, all MCS commands are
+	 * ignored by the display interface.
+	 */
+	status = i2c_smbus_read_byte_data(client, PAGE2_MCS_EN);
+	if (status < 0) {
+		DRM_ERROR("failed read PAGE2_MCS_EN: %d\n", status);
+		goto err_regulators_disable;
+	}
+
+	ret = i2c_smbus_write_byte_data(client, PAGE2_MCS_EN,
+					status & ~MCS_EN);
+	if (ret < 0) {
+		DRM_ERROR("failed write PAGE2_MCS_EN: %d\n", ret);
+		goto err_regulators_disable;
+	}
+
+	ret = ps8640_bridge_unmute(ps_bridge);
+	if (ret)
+		DRM_ERROR("failed to enable unmutevideo: %d\n", ret);
+
+	/* Switch access edp panel's edid through i2c */
+	ret = i2c_smbus_write_byte_data(client, PAGE2_I2C_BYPASS,
+					I2C_BYPASS_EN);
+	if (ret < 0) {
+		DRM_ERROR("failed write PAGE2_I2C_BYPASS: %d\n", ret);
+		goto err_regulators_disable;
+	}
+
+	return;
+
+err_regulators_disable:
+	regulator_bulk_disable(ARRAY_SIZE(ps_bridge->supplies),
+			       ps_bridge->supplies);
+}
+
+static void ps8640_post_disable(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	int ret;
+
+	ret = ps8640_bridge_mute(ps_bridge);
+	if (ret < 0)
+		DRM_ERROR("failed to unmutevideo: %d\n", ret);
+
+	gpiod_set_value(ps_bridge->gpio_reset, 0);
+	gpiod_set_value(ps_bridge->gpio_powerdown, 0);
+	ret = regulator_bulk_disable(ARRAY_SIZE(ps_bridge->supplies),
+				     ps_bridge->supplies);
+	if (ret < 0)
+		DRM_ERROR("cannot disable regulators %d\n", ret);
+}
+
+int ps8640_bridge_attach(struct drm_bridge *bridge)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+	struct device *dev = &ps_bridge->page[0]->dev;
+	struct device_node *in_ep, *dsi_node;
+	struct mipi_dsi_device *dsi;
+	struct mipi_dsi_host *host;
+	int ret;
+	const struct mipi_dsi_device_info info = { .type = "ps8640",
+						   .channel = 0,
+						   .node = NULL,
+						 };
+	/* port@0 is ps8640 dsi input port */
+	in_ep = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
+	if (!in_ep)
+		return -ENODEV;
+
+	dsi_node = of_graph_get_remote_port_parent(in_ep);
+	of_node_put(in_ep);
+	if (!dsi_node)
+		return -ENODEV;
+
+	host = of_find_mipi_dsi_host_by_node(dsi_node);
+	of_node_put(dsi_node);
+	if (!host)
+		return -ENODEV;
+
+	dsi = mipi_dsi_device_register_full(host, &info);
+	if (IS_ERR(dsi)) {
+		dev_err(dev, "failed to create dsi device\n");
+		ret = PTR_ERR(dsi);
+		return ret;
+	}
+
+	ps_bridge->dsi = dsi;
+
+	dsi->host = host;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
+			  MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->lanes = 4;
+	ret = mipi_dsi_attach(dsi);
+	if (ret)
+		goto err_dsi_attach;
+
+	/* Attach the panel-bridge to the dsi bridge */
+	return drm_bridge_attach(bridge->encoder, ps_bridge->panel_bridge,
+				 &ps_bridge->bridge);
+
+err_dsi_attach:
+	mipi_dsi_device_unregister(dsi);
+	return ret;
+}
+
+static const struct drm_bridge_funcs ps8640_bridge_funcs = {
+	.attach = ps8640_bridge_attach,
+	.post_disable = ps8640_post_disable,
+	.pre_enable = ps8640_pre_enable,
+};
+
+static int ps8640_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct device_node *np = dev->of_node;
+	struct ps8640 *ps_bridge;
+	struct drm_panel *panel;
+	int ret;
+	u32 i;
+
+	ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
+	if (!ps_bridge)
+		return -ENOMEM;
+
+	/* port@1 is ps8640 output port */
+	ret = drm_of_find_panel_or_bridge(np, 1, 0, &panel, NULL);
+	if (ret < 0)
+		return ret;
+	if (!panel)
+		return -ENODEV;
+
+	panel->connector_type = DRM_MODE_CONNECTOR_eDP;
+
+	ps_bridge->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
+	if (IS_ERR(ps_bridge->panel_bridge))
+		return PTR_ERR(ps_bridge->panel_bridge);
+
+	ps_bridge->supplies[0].supply = "vdd33";
+	ps_bridge->supplies[1].supply = "vdd12";
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ps_bridge->supplies),
+				      ps_bridge->supplies);
+	if (ret)
+		return ret;
+
+	ps_bridge->gpio_powerdown = devm_gpiod_get(&client->dev, "powerdown",
+						   GPIOD_OUT_LOW);
+	if (IS_ERR(ps_bridge->gpio_powerdown))
+		return PTR_ERR(ps_bridge->gpio_powerdown);
+
+	/*
+	 * Request the reset pin low to avoid the bridge being
+	 * initialized prematurely
+	 */
+	ps_bridge->gpio_reset = devm_gpiod_get(&client->dev, "reset",
+					       GPIOD_OUT_LOW);
+	if (IS_ERR(ps_bridge->gpio_reset))
+		return PTR_ERR(ps_bridge->gpio_reset);
+
+	ps_bridge->bridge.funcs = &ps8640_bridge_funcs;
+	ps_bridge->bridge.of_node = dev->of_node;
+
+	ps_bridge->page[PAGE0_DP_CNTL] = client;
+
+	for (i = 1; i < ARRAY_SIZE(ps_bridge->page); i++) {
+		ps_bridge->page[i] = devm_i2c_new_dummy_device(&client->dev,
+							     client->adapter,
+							     client->addr + i);
+		if (IS_ERR(ps_bridge->page[i])) {
+			dev_err(dev, "failed i2c dummy device, address%02x\n",
+				client->addr + i);
+			return PTR_ERR(ps_bridge->page[i]);
+		}
+	}
+
+	i2c_set_clientdata(client, ps_bridge);
+
+	drm_bridge_add(&ps_bridge->bridge);
+
+	return 0;
+}
+
+static int ps8640_remove(struct i2c_client *client)
+{
+	struct ps8640 *ps_bridge = i2c_get_clientdata(client);
+
+	drm_bridge_remove(&ps_bridge->bridge);
+
+	return 0;
+}
+
+static const struct of_device_id ps8640_match[] = {
+	{ .compatible = "parade,ps8640" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ps8640_match);
+
+static struct i2c_driver ps8640_driver = {
+	.probe_new = ps8640_probe,
+	.remove = ps8640_remove,
+	.driver = {
+		.name = "ps8640",
+		.of_match_table = ps8640_match,
+	},
+};
+module_i2c_driver(ps8640_driver);
+
+MODULE_AUTHOR("Jitao Shi <jitao.shi@mediatek.com>");
+MODULE_AUTHOR("CK Hu <ck.hu@mediatek.com>");
+MODULE_DESCRIPTION("PARADE ps8640 DSI-eDP converter driver");
+MODULE_LICENSE("GPL v2");
-- 
2.20.1