2013/10/3 Sean Paul <seanpaul@xxxxxxxxxxxx>: > On Thu, Oct 3, 2013 at 9:55 AM, Inki Dae <inki.dae@xxxxxxxxxxx> wrote: >> Hi, thank you for your contribution and the below is my short comments, >> >> 2013/10/2 Sean Paul <seanpaul@xxxxxxxxxxxx>: >>> This patch adds a drm_bridge driver for the PTN3460 DisplayPort to LVDS >>> bridge chip. >>> >>> Signed-off-by: Sean Paul <seanpaul@xxxxxxxxxxxx> >>> --- >>> .../devicetree/bindings/drm/bridge/ptn3460.txt | 27 ++ >>> drivers/gpu/drm/Kconfig | 2 + >>> drivers/gpu/drm/Makefile | 1 + >>> drivers/gpu/drm/bridge/Kconfig | 4 + >>> drivers/gpu/drm/bridge/Makefile | 3 + >>> drivers/gpu/drm/bridge/ptn3460.c | 349 +++++++++++++++++++++ >>> include/drm/bridge/ptn3460.h | 36 +++ >>> 7 files changed, 422 insertions(+) >>> create mode 100644 Documentation/devicetree/bindings/drm/bridge/ptn3460.txt >>> create mode 100644 drivers/gpu/drm/bridge/Kconfig >>> create mode 100644 drivers/gpu/drm/bridge/Makefile >>> create mode 100644 drivers/gpu/drm/bridge/ptn3460.c >>> create mode 100644 include/drm/bridge/ptn3460.h >>> >>> diff --git a/Documentation/devicetree/bindings/drm/bridge/ptn3460.txt b/Documentation/devicetree/bindings/drm/bridge/ptn3460.txt >>> new file mode 100644 >>> index 0000000..c1cd329 >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/drm/bridge/ptn3460.txt >>> @@ -0,0 +1,27 @@ >>> +ptn3460-bridge bindings >>> + >>> +Required properties: >>> + - compatible: "nxp,ptn3460" >>> + - reg: i2c address of the bridge >>> + - powerdown-gpio: OF device-tree gpio specification >> >> Can a regulator be used instead of gpio in other board case? >> > > No, not to my knowledge. > Hm.. plz check it out again. the gpio pin is specific to board, and the the gpio be used as power source trigger could be replaced with a regulator according to board design. So you should consider all possibilities even though there are no other cases yet: other board could use a regulator instead. > >>> + - reset-gpio: OF device-tree gpio specification >>> + - edid-emulation: The EDID emulation entry to use >>> + +-------+------------+------------------+ >>> + | Value | Resolution | Description | >>> + | 0 | 1024x768 | NXP Generic | >>> + | 1 | 1920x1080 | NXP Generic | >>> + | 2 | 1920x1080 | NXP Generic | >>> + | 3 | 1600x900 | Samsung LTM200KT | >>> + | 4 | 1920x1080 | Samsung LTM230HT | >>> + | 5 | 1366x768 | NXP Generic | >>> + | 6 | 1600x900 | ChiMei M215HGE | >>> + +-------+------------+------------------+ >>> + >>> +Example: >>> + ptn3460-bridge@20 { >>> + compatible = "nxp,ptn3460"; >>> + reg = <0x20>; >>> + powerdown-gpio = <&gpy2 5 1 0 0>; >>> + reset-gpio = <&gpx1 5 1 0 0>; >>> + edid-emulation = <5>; >>> + }; >>> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig >>> index 955555d..cd7bfb3 100644 >>> --- a/drivers/gpu/drm/Kconfig >>> +++ b/drivers/gpu/drm/Kconfig >>> @@ -236,3 +236,5 @@ source "drivers/gpu/drm/tilcdc/Kconfig" >>> source "drivers/gpu/drm/qxl/Kconfig" >>> >>> source "drivers/gpu/drm/msm/Kconfig" >>> + >>> +source "drivers/gpu/drm/bridge/Kconfig" >>> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile >>> index f089adf..9234253 100644 >>> --- a/drivers/gpu/drm/Makefile >>> +++ b/drivers/gpu/drm/Makefile >>> @@ -56,3 +56,4 @@ obj-$(CONFIG_DRM_TILCDC) += tilcdc/ >>> obj-$(CONFIG_DRM_QXL) += qxl/ >>> obj-$(CONFIG_DRM_MSM) += msm/ >>> obj-y += i2c/ >>> +obj-y += bridge/ >>> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig >>> new file mode 100644 >>> index 0000000..f8db069 >>> --- /dev/null >>> +++ b/drivers/gpu/drm/bridge/Kconfig >>> @@ -0,0 +1,4 @@ >>> +config DRM_PTN3460 >>> + tristate "PTN3460 DP/LVDS bridge" >>> + depends on DRM && I2C >>> + ---help--- >>> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile >>> new file mode 100644 >>> index 0000000..b4733e1 >>> --- /dev/null >>> +++ b/drivers/gpu/drm/bridge/Makefile >>> @@ -0,0 +1,3 @@ >>> +ccflags-y := -Iinclude/drm >>> + >>> +obj-$(CONFIG_DRM_PTN3460) += ptn3460.o >>> diff --git a/drivers/gpu/drm/bridge/ptn3460.c b/drivers/gpu/drm/bridge/ptn3460.c >>> new file mode 100644 >>> index 0000000..a9e5c1a >>> --- /dev/null >>> +++ b/drivers/gpu/drm/bridge/ptn3460.c >>> @@ -0,0 +1,349 @@ >>> +/* >>> + * NXP PTN3460 DP/LVDS bridge driver >>> + * >>> + * Copyright (C) 2013 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/module.h> >>> +#include <linux/of.h> >>> +#include <linux/of_gpio.h> >>> +#include <linux/i2c.h> >>> +#include <linux/gpio.h> >>> +#include <linux/delay.h> >>> + >>> +#include "drmP.h" >>> +#include "drm_edid.h" >>> +#include "drm_crtc.h" >>> +#include "drm_crtc_helper.h" >>> + >>> +#include "bridge/ptn3460.h" >>> + >>> +#define PTN3460_EDID_ADDR 0x0 >>> +#define PTN3460_EDID_EMULATION_ADDR 0x84 >>> +#define PTN3460_EDID_ENABLE_EMULATION 0 >>> +#define PTN3460_EDID_EMULATION_SELECTION 1 >>> +#define PTN3460_EDID_SRAM_LOAD_ADDR 0x85 >>> + >>> +struct ptn3460_bridge { >>> + struct drm_connector connector; >>> + struct i2c_client *client; >>> + struct drm_encoder *encoder; >>> + struct drm_bridge *bridge; >>> + struct edid *edid; >>> + int gpio_pd_n; >>> + int gpio_rst_n; >>> + u32 edid_emulation; >>> + bool enabled; >>> +}; >>> + >>> +static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr, >>> + u8 *buf, int len) >>> +{ >>> + int ret; >>> + >>> + ret = i2c_master_send(ptn_bridge->client, &addr, 1); >>> + if (ret <= 0) { >>> + DRM_ERROR("Failed to send i2c command, ret=%d\n", ret); >>> + return ret; >>> + } >>> + >>> + ret = i2c_master_recv(ptn_bridge->client, buf, len); >>> + if (ret <= 0) { >>> + DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret); >>> + return ret; >>> + } >>> + >>> + return 0; >>> +} >>> + >>> +static int ptn3460_write_byte(struct ptn3460_bridge *ptn_bridge, char addr, >>> + char val) >>> +{ >>> + int ret; >>> + char buf[2]; >>> + >>> + buf[0] = addr; >>> + buf[1] = val; >>> + >>> + ret = i2c_master_send(ptn_bridge->client, buf, ARRAY_SIZE(buf)); >>> + if (ret <= 0) { >>> + DRM_ERROR("Failed to send i2c command, ret=%d\n", ret); >>> + return ret; >>> + } >>> + >>> + return 0; >>> +} >>> + >>> +static int ptn3460_select_edid(struct ptn3460_bridge *ptn_bridge) >>> +{ >>> + int ret; >>> + char val; >>> + >>> + /* Load the selected edid into SRAM (accessed at PTN3460_EDID_ADDR) */ >>> + ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_SRAM_LOAD_ADDR, >>> + ptn_bridge->edid_emulation); >>> + if (ret) { >>> + DRM_ERROR("Failed to transfer edid to sram, ret=%d\n", ret); >>> + return ret; >>> + } >>> + >>> + /* Enable EDID emulation and select the desired EDID */ >>> + val = 1 << PTN3460_EDID_ENABLE_EMULATION | >>> + ptn_bridge->edid_emulation << PTN3460_EDID_EMULATION_SELECTION; >>> + >>> + ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_EMULATION_ADDR, val); >>> + if (ret) { >>> + DRM_ERROR("Failed to write edid value, ret=%d\n", ret); >>> + return ret; >>> + } >>> + >>> + return 0; >>> +} >>> + >>> +static void ptn3460_pre_enable(struct drm_bridge *bridge) >>> +{ >>> + struct ptn3460_bridge *ptn_bridge = bridge->driver_private; >>> + int ret; >>> + >>> + if (ptn_bridge->enabled) >>> + return; >>> + >>> + if (gpio_is_valid(ptn_bridge->gpio_pd_n)) >>> + gpio_set_value(ptn_bridge->gpio_pd_n, 1); >> >> Ditto. >> >>> + >>> + if (gpio_is_valid(ptn_bridge->gpio_rst_n)) { >>> + gpio_set_value(ptn_bridge->gpio_rst_n, 0); >>> + udelay(10); >>> + gpio_set_value(ptn_bridge->gpio_rst_n, 1); >>> + } >>> + >>> + /* >>> + * There's a bug in the PTN chip where it falsely asserts hotplug before >>> + * it is fully functional. We're forced to wait for the maximum start up >>> + * time specified in the chip's datasheet to make sure we're really up. >>> + */ >>> + msleep(90); >>> + >>> + ret = ptn3460_select_edid(ptn_bridge); >>> + if (ret) >>> + DRM_ERROR("Select edid failed ret=%d\n", ret); >>> + >>> + ptn_bridge->enabled = true; >>> +} >>> + >>> +static void ptn3460_enable(struct drm_bridge *bridge) >>> +{ >>> +} >>> + >>> +static void ptn3460_disable(struct drm_bridge *bridge) >>> +{ >>> + struct ptn3460_bridge *ptn_bridge = bridge->driver_private; >>> + >>> + if (!ptn_bridge->enabled) >>> + return; >>> + >>> + ptn_bridge->enabled = false; >>> + >>> + if (gpio_is_valid(ptn_bridge->gpio_rst_n)) >>> + gpio_set_value(ptn_bridge->gpio_rst_n, 1); >>> + >>> + if (gpio_is_valid(ptn_bridge->gpio_pd_n)) >>> + gpio_set_value(ptn_bridge->gpio_pd_n, 0); >> >> Ditto. >> >>> +} >>> + >>> +static void ptn3460_post_disable(struct drm_bridge *bridge) >>> +{ >>> +} >>> + >>> +void ptn3460_bridge_destroy(struct drm_bridge *bridge) >>> +{ >>> + struct ptn3460_bridge *ptn_bridge = bridge->driver_private; >>> + >>> + drm_bridge_cleanup(bridge); >>> + if (gpio_is_valid(ptn_bridge->gpio_pd_n)) >>> + gpio_free(ptn_bridge->gpio_pd_n); >> >> Ditto. >> >>> + if (gpio_is_valid(ptn_bridge->gpio_rst_n)) >>> + gpio_free(ptn_bridge->gpio_rst_n); >>> + /* Nothing else to free, we've got devm allocated memory */ >>> +} >>> + >>> +struct drm_bridge_funcs ptn3460_bridge_funcs = { >>> + .pre_enable = ptn3460_pre_enable, >>> + .enable = ptn3460_enable, >>> + .disable = ptn3460_disable, >>> + .post_disable = ptn3460_post_disable, >>> + .destroy = ptn3460_bridge_destroy, >>> +}; >>> + >>> +int ptn3460_get_modes(struct drm_connector *connector) >>> +{ >>> + struct ptn3460_bridge *ptn_bridge; >>> + u8 *edid; >>> + int ret, num_modes; >>> + bool power_off; >>> + >>> + ptn_bridge = container_of(connector, struct ptn3460_bridge, connector); >>> + >>> + if (ptn_bridge->edid) >>> + return drm_add_edid_modes(connector, ptn_bridge->edid); >>> + >>> + power_off = !ptn_bridge->enabled; >>> + ptn3460_pre_enable(ptn_bridge->bridge); >>> + >>> + edid = kmalloc(EDID_LENGTH, GFP_KERNEL); >>> + if (!edid) { >>> + DRM_ERROR("Failed to allocate edid\n"); >>> + return 0; >>> + } >>> + >>> + ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid, >>> + EDID_LENGTH); >>> + if (ret) { >>> + kfree(edid); >>> + num_modes = 0; >>> + goto out; >>> + } >>> + >>> + ptn_bridge->edid = (struct edid *)edid; >>> + drm_mode_connector_update_edid_property(connector, ptn_bridge->edid); >>> + >>> + num_modes = drm_add_edid_modes(connector, ptn_bridge->edid); >>> + >>> +out: >>> + if (power_off) >>> + ptn3460_disable(ptn_bridge->bridge); >>> + >>> + return num_modes; >>> +} >>> + >>> +static int ptn3460_mode_valid(struct drm_connector *connector, >>> + struct drm_display_mode *mode) >>> +{ >>> + return MODE_OK; >>> +} >>> + >>> +struct drm_encoder *ptn3460_best_encoder(struct drm_connector *connector) >>> +{ >>> + struct ptn3460_bridge *ptn_bridge; >>> + >>> + ptn_bridge = container_of(connector, struct ptn3460_bridge, connector); >>> + >>> + return ptn_bridge->encoder; >>> +} >>> + >>> +struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = { >>> + .get_modes = ptn3460_get_modes, >>> + .mode_valid = ptn3460_mode_valid, >>> + .best_encoder = ptn3460_best_encoder, >>> +}; >>> + >>> +enum drm_connector_status ptn3460_detect(struct drm_connector *connector, >>> + bool force) >>> +{ >>> + return connector_status_connected; >>> +} >>> + >>> +void ptn3460_connector_destroy(struct drm_connector *connector) >>> +{ >>> + drm_connector_cleanup(connector); >>> +} >>> + >>> +struct drm_connector_funcs ptn3460_connector_funcs = { >>> + .dpms = drm_helper_connector_dpms, >>> + .fill_modes = drm_helper_probe_single_connector_modes, >>> + .detect = ptn3460_detect, >>> + .destroy = ptn3460_connector_destroy, >>> +}; >> >> Why do you try to add a new connector here? We already have the >> connector for LCD, and also provides some callbacks for it. For this, >> please see exynos_drm_display_ops of exynos_drm_fimd driver, and you >> can add new callbacks to there such as init callback for bridge device >> initialization if needed. >> > > We add a new connector for 2 reasons: > > 1) We need to override the drm detect() callback to always return true > since the DP driver will presumably return its hotplug status which > will always be low when the ptn chip is turned off. > 2) We want the ability to control the result of get_modes(). > > I've got a patch set almost ready to tear the display ops out of fimd > and put them in the DP driver. Really? if so, that is ideal something we want and we should go. But isn't the DP driver placed in drivers/video/exynos? How did you take care of that? Actually, for this, we planned to use CDF(Common Display Framework) if the framework is merged to mainline somehow. > The display ops are better suited > there, since it's the actual encoder/connector. I hope to get that > posted this week. > I will look forward to that posting. :) > >>> + >>> +int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder, >>> + struct i2c_client *client, struct device_node *node) >>> +{ >>> + int ret; >>> + struct drm_bridge *bridge; >>> + struct ptn3460_bridge *ptn_bridge; >>> + >>> + bridge = devm_kzalloc(dev->dev, sizeof(*bridge), GFP_KERNEL); >>> + if (!bridge) { >>> + DRM_ERROR("Failed to allocate drm bridge\n"); >>> + return -ENOMEM; >>> + } >>> + >>> + ptn_bridge = devm_kzalloc(dev->dev, sizeof(*ptn_bridge), GFP_KERNEL); >>> + if (!ptn_bridge) { >>> + DRM_ERROR("Failed to allocate ptn bridge\n"); >>> + return -ENOMEM; >>> + } >>> + >>> + ptn_bridge->client = client; >>> + ptn_bridge->encoder = encoder; >>> + ptn_bridge->bridge = bridge; >>> + ptn_bridge->gpio_pd_n = of_get_named_gpio(node, "powerdown-gpio", 0); >> >> Also, if a regulator is used instead? >> >>> + if (gpio_is_valid(ptn_bridge->gpio_pd_n)) { >>> + ret = gpio_request_one(ptn_bridge->gpio_pd_n, >>> + GPIOF_OUT_INIT_HIGH, "PTN3460_PD_N"); >>> + if (ret) { >>> + DRM_ERROR("Request powerdown-gpio failed (%d)\n", ret); >>> + return ret; >>> + } >>> + } >>> + >>> + ptn_bridge->gpio_rst_n = of_get_named_gpio(node, "reset-gpio", 0); >>> + if (gpio_is_valid(ptn_bridge->gpio_rst_n)) { >>> + /* >>> + * Request the reset pin low to avoid the bridge being >>> + * initialized prematurely >>> + */ >>> + ret = gpio_request_one(ptn_bridge->gpio_rst_n, >>> + GPIOF_OUT_INIT_LOW, "PTN3460_RST_N"); >>> + if (ret) { >>> + DRM_ERROR("Request reset-gpio failed (%d)\n", ret); >>> + gpio_free(ptn_bridge->gpio_pd_n); >>> + return ret; >>> + } >>> + } >>> + >>> + ret = of_property_read_u32(node, "edid-emulation", >>> + &ptn_bridge->edid_emulation); >>> + if (ret) { >>> + DRM_ERROR("Can't read edid emulation value\n"); >>> + goto err; >>> + } >>> + >>> + ret = drm_bridge_init(dev, bridge, &ptn3460_bridge_funcs); >>> + if (ret) { >>> + DRM_ERROR("Failed to initialize bridge with drm\n"); >>> + goto err; >>> + } >>> + >>> + bridge->driver_private = ptn_bridge; >>> + encoder->bridge = bridge; >>> + >>> + ret = drm_connector_init(dev, &ptn_bridge->connector, >>> + &ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS); >> >> So it seems that here's not right place to call drm_connector_init function. >> >> Display pipeline path could be one of, >> Display Controller Display bus >> --------------------------------------------------------------------------- >> FIMD---------------------LVDS--------------------LCD, >> or >> FIMD----------------------eDP---------------------LCD, >> or >> FIMD------------------MIPI-DSI------------------LCD, >> or >> FIMD-------------------------------------------------LCD >> >> And also in case using image enhancement chip, >> mDNIe-------------FIMD-LITE between Display Controller and Display >> bus. >> >> So, wouldn't the right place below FIMD driver? :) >> > > Well, this driver should be considered outside of exynos context since > it could be used by any drm driver. > > In the exynos context, the right place to implement it would be in the > dp driver, actually. However, the exynos driver has a level of > abstraction on top of the crtcs/encoders such that we need to > initialize it in the exynos_drm_core. The patchset I mentioned above > should help move things in a direction where fimd/mixer implement > drm_crtc directly and hdmi/dp implement drm_encoder/drm_connector > directly. In that world, DP would initialize the ptn driver. > >> >>> + if (ret) { >>> + DRM_ERROR("Failed to initialize connector with drm\n"); >>> + goto err; >>> + } >>> + drm_connector_helper_add(&ptn_bridge->connector, >>> + &ptn3460_connector_helper_funcs); >>> + drm_sysfs_connector_add(&ptn_bridge->connector); >>> + drm_mode_connector_attach_encoder(&ptn_bridge->connector, encoder); >>> + >>> + return 0; >>> + >>> +err: >>> + if (gpio_is_valid(ptn_bridge->gpio_pd_n)) >>> + gpio_free(ptn_bridge->gpio_pd_n); >>> + if (gpio_is_valid(ptn_bridge->gpio_rst_n)) >>> + gpio_free(ptn_bridge->gpio_rst_n); >>> + return ret; >>> +} >>> diff --git a/include/drm/bridge/ptn3460.h b/include/drm/bridge/ptn3460.h >>> new file mode 100644 >>> index 0000000..157ffa1 >>> --- /dev/null >>> +++ b/include/drm/bridge/ptn3460.h >>> @@ -0,0 +1,36 @@ >>> +/* >>> + * Copyright (C) 2013 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. >>> + */ >>> + >>> +#ifndef _DRM_BRIDGE_PTN3460_H_ >>> +#define _DRM_BRIDGE_PTN3460_H_ >>> + >>> +struct drm_device; >>> +struct drm_encoder; >>> +struct i2c_client; >>> +struct device_node; >>> + >>> +#ifdef CONFIG_DRM_PTN3460 >>> + >>> +int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder, >>> + struct i2c_client *client, struct device_node *node); >>> +#else >>> + >>> +int ptn3460_init(struct drm_device *dev, struct drm_encoder *encoder, >>> + struct i2c_client *client, struct device_node *node) >>> +{ >>> + return 0; >>> +} >>> + >>> +#endif >>> + >>> +#endif >>> -- >>> 1.8.4 >>> >>> >>> _______________________________________________ >>> linux-arm-kernel mailing list >>> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx >>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/dri-devel -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html