[PATCH v22 2/2] drm/bridge: Add I2C based driver for ps8640 bridge

From: Enric Balletbo i Serra
Date: Fri Dec 20 2019 - 03:17:58 EST


From: Jitao Shi <jitao.shi@xxxxxxxxxxxx>

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

Signed-off-by: Jitao Shi <jitao.shi@xxxxxxxxxxxx>
Reviewed-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
[uli: followed API changes, removed FW update feature]
Signed-off-by: Ulrich Hecht <uli@xxxxxxxx>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
---
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@xxxxxxxxxxxx>");
+MODULE_AUTHOR("CK Hu <ck.hu@xxxxxxxxxxxx>");
+MODULE_DESCRIPTION("PARADE ps8640 DSI-eDP converter driver");
+MODULE_LICENSE("GPL v2");
--
2.20.1