From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031077AbdAEHtT (ORCPT ); Thu, 5 Jan 2017 02:49:19 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:49748 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030990AbdAEHtQ (ORCPT ); Thu, 5 Jan 2017 02:49:16 -0500 DMARC-Filter: OpenDMARC Filter v1.3.1 smtp.codeaurora.org DB6AF600D0 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=pass smtp.mailfrom=architt@codeaurora.org Subject: Re: [PATCH V7 3/4] drm/bridge: Add driver for GE B850v3 LVDS/DP++ Bridge To: Peter Senna Tschudin , airlied@linux.ie, akpm@linux-foundation.org, daniel.vetter@ffwll.ch, davem@davemloft.net, devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org, enric.balletbo@collabora.com, eballetbo@gmail.com, galak@codeaurora.org, gregkh@linuxfoundation.org, heiko@sntech.de, ijc+devicetree@hellion.org.uk, javier@dowhile0.org, jslaby@suse.cz, kernel@pengutronix.de, linux-arm-kernel@lists.infradead.org, linux@armlinux.org.uk, linux-kernel@vger.kernel.org, linux@roeck-us.net, mark.rutland@arm.com, martin.donnelly@ge.com, martyn.welch@collabora.co.uk, mchehab@osg.samsung.com, pawel.moll@arm.com, peter.senna@gmail.com, p.zabel@pengutronix.de, thierry.reding@gmail.com, rmk+kernel@armlinux.org.uk, robh+dt@kernel.org, shawnguo@kernel.org, tiwai@suse.com, treding@nvidia.com, ykk@rock-chips.com References: <4232c88a99f44a24287d04d74b891e2eb139864c.1483301745.git.peter.senna@collabora.com> Cc: Rob Herring , Fabio Estevam From: Archit Taneja Message-ID: <759f96e2-43da-45ba-cf8d-55bc1f6e8442@codeaurora.org> Date: Thu, 5 Jan 2017 13:18:47 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <4232c88a99f44a24287d04d74b891e2eb139864c.1483301745.git.peter.senna@collabora.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Some comments below. On 01/02/2017 01:54 AM, Peter Senna Tschudin wrote: > Add a driver that create a drm_bridge and a drm_connector for the LVDS > to DP++ display bridge of the GE B850v3. > > There are two physical bridges on the video signal pipeline: a > STDP4028(LVDS to DP) and a STDP2690(DP to DP++). The hardware and > firmware made it complicated for this binding to comprise two device > tree nodes, as the design goal is to configure both bridges based on > the LVDS signal, which leave the driver powerless to control the video > processing pipeline. The two bridges behaves as a single bridge, and > the driver is only needed for telling the host about EDID / HPD, and > for giving the host powers to ack interrupts. The video signal pipeline > is as follows: > > Host -> LVDS|--(STDP4028)--|DP -> DP|--(STDP2690)--|DP++ -> Video output > > Cc: Martyn Welch > Cc: Martin Donnelly > Cc: Daniel Vetter > Cc: Enric Balletbo i Serra > Cc: Philipp Zabel > Cc: Rob Herring > Cc: Fabio Estevam > CC: David Airlie > CC: Thierry Reding > CC: Thierry Reding > CC: Archit Taneja > Reviewed-by: Enric Balletbo > Signed-off-by: Peter Senna Tschudin > --- > drivers/gpu/drm/bridge/Kconfig | 11 + > drivers/gpu/drm/bridge/Makefile | 1 + > drivers/gpu/drm/bridge/ge_b850v3_lvds_dp.c | 384 +++++++++++++++++++++++++++++ > 3 files changed, 396 insertions(+) > create mode 100644 drivers/gpu/drm/bridge/ge_b850v3_lvds_dp.c > > diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig > index eb8688e..e3e1f3b 100644 > --- a/drivers/gpu/drm/bridge/Kconfig > +++ b/drivers/gpu/drm/bridge/Kconfig > @@ -48,6 +48,17 @@ config DRM_DW_HDMI_I2S_AUDIO > Support the I2S Audio interface which is part of the Synopsis > Designware HDMI block. > > +config DRM_GE_B850V3_LVDS_DP > + tristate "GE B850v3 LVDS to DP++ display bridge" > + depends on OF > + select DRM_KMS_HELPER > + select DRM_PANEL > + ---help--- > + This is a driver for the display bridge of > + GE B850v3 that convert dual channel LVDS > + to DP++. This is used with the i.MX6 imx-ldb > + driver. > + > config DRM_NXP_PTN3460 > tristate "NXP PTN3460 DP/LVDS bridge" > depends on OF > diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile > index 2e83a785..886d0fd 100644 > --- a/drivers/gpu/drm/bridge/Makefile > +++ b/drivers/gpu/drm/bridge/Makefile > @@ -5,6 +5,7 @@ obj-$(CONFIG_DRM_DUMB_VGA_DAC) += dumb-vga-dac.o > obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o > obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o > obj-$(CONFIG_DRM_DW_HDMI_I2S_AUDIO) += dw-hdmi-i2s-audio.o > +obj-$(CONFIG_DRM_GE_B850V3_LVDS_DP) += ge_b850v3_lvds_dp.o > obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o > obj-$(CONFIG_DRM_PARADE_PS8622) += parade-ps8622.o > obj-$(CONFIG_DRM_SIL_SII8620) += sil-sii8620.o > diff --git a/drivers/gpu/drm/bridge/ge_b850v3_lvds_dp.c b/drivers/gpu/drm/bridge/ge_b850v3_lvds_dp.c > new file mode 100644 > index 0000000..4574f6e > --- /dev/null > +++ b/drivers/gpu/drm/bridge/ge_b850v3_lvds_dp.c > @@ -0,0 +1,384 @@ > +/* > + * Driver for GE B850v3 DP display bridge Mentioning LVDS to DP++ here would be nice. > + > + * Copyright (c) 2016, Collabora Ltd. > + * Copyright (c) 2016, General Electric Company > + > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + > + * This program is distributed in the hope 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. > + > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see . > + > + * This driver creates a drm_bridge and a drm_connector for the LVDS to DP++ > + * display bridge of the GE B850v3. There are two physical bridges on the video > + * signal pipeline: a STDP4028(LVDS to DP) and a STDP2690(DP to DP++). However > + * the physical bridges are automatically configured by the input video signal, > + * and the driver has no access to the video processing pipeline. The driver is > + * only needed to read EDID from the STDP2690 and to handle HPD events from the > + * STDP4028. The driver communicates with both bridges over i2c. The video > + * signal pipeline is as follows: > + * > + * Host -> LVDS|--(STDP4028)--|DP -> DP|--(STDP2690)--|DP++ -> Video output > + * > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define DEFAULT_EDID_REG 0x72 > +#define DEFAULT_EDID_REG_NAME "edid" > + > +#define EDID_EXT_BLOCK_CNT 0x7E > + > +#define STDP4028_IRQ_OUT_CONF_REG 0x02 > +#define STDP4028_DPTX_IRQ_EN_REG 0x3C > +#define STDP4028_DPTX_IRQ_STS_REG 0x3D > +#define STDP4028_DPTX_STS_REG 0x3E > + > +#define STDP4028_DPTX_DP_IRQ_EN 0x1000 > + > +#define STDP4028_DPTX_HOTPLUG_IRQ_EN 0x0400 > +#define STDP4028_DPTX_LINK_CH_IRQ_EN 0x2000 > +#define STDP4028_DPTX_IRQ_CONFIG \ > + (STDP4028_DPTX_LINK_CH_IRQ_EN | STDP4028_DPTX_HOTPLUG_IRQ_EN) > + > +#define STDP4028_DPTX_HOTPLUG_STS 0x0200 > +#define STDP4028_DPTX_LINK_STS 0x1000 > +#define STDP4028_CON_STATE_CONNECTED \ > + (STDP4028_DPTX_HOTPLUG_STS | STDP4028_DPTX_LINK_STS) > + > +#define STDP4028_DPTX_HOTPLUG_CH_STS 0x0400 > +#define STDP4028_DPTX_LINK_CH_STS 0x2000 > +#define STDP4028_DPTX_IRQ_CLEAR \ > + (STDP4028_DPTX_LINK_CH_STS | STDP4028_DPTX_HOTPLUG_CH_STS) > + > +struct ge_b850v3_lvds_dp { > + struct drm_connector connector; > + struct drm_bridge bridge; > + struct i2c_client *ge_b850v3_lvds_dp_i2c; > + struct i2c_client *edid_i2c; > + struct edid *edid; > + struct mutex edid_mutex; > + struct mutex irq_reg_mutex; > +}; > + > +static inline struct ge_b850v3_lvds_dp * > + bridge_to_ge_b850v3_lvds_dp(struct drm_bridge *bridge) > +{ > + return container_of(bridge, struct ge_b850v3_lvds_dp, bridge); > +} > + > +static inline struct ge_b850v3_lvds_dp * > + connector_to_ge_b850v3_lvds_dp(struct drm_connector *connector) > +{ > + return container_of(connector, struct ge_b850v3_lvds_dp, connector); > +} > + > +u8 *stdp2690_get_edid(struct i2c_client *client) > +{ > + struct i2c_adapter *adapter = client->adapter; > + unsigned char start = 0x00; > + unsigned int total_size; > + u8 *block = kmalloc(EDID_LENGTH, GFP_KERNEL); > + > + struct i2c_msg msgs[] = { > + { > + .addr = client->addr, > + .flags = 0, > + .len = 1, > + .buf = &start, > + }, { > + .addr = client->addr, > + .flags = I2C_M_RD, > + .len = EDID_LENGTH, > + .buf = block, > + } > + }; > + > + if (!block) > + return NULL; > + > + if (i2c_transfer(adapter, msgs, 2) != 2) { > + DRM_ERROR("Unable to read EDID.\n"); > + goto err; > + } > + > + if (!drm_edid_block_valid(block, 0, false, NULL)) { > + DRM_ERROR("Invalid EDID block\n"); > + goto err; > + } > + > + total_size = (block[EDID_EXT_BLOCK_CNT] + 1) * EDID_LENGTH; > + if (total_size > EDID_LENGTH) { > + kfree(block); > + block = kmalloc(total_size, GFP_KERNEL); > + if (!block) > + return NULL; > + > + /* Yes, read the entire buffer, and do not skip the first > + * EDID_LENGTH bytes. > + */ Is this the reason why you aren't using drm_do_get_edid()? > + start = 0x00; > + msgs[1].len = total_size; > + msgs[1].buf = block; > + > + if (i2c_transfer(adapter, msgs, 2) != 2) { > + DRM_ERROR("Unable to read EDID extension blocks.\n"); > + goto err; > + } We should ideally check if the extension blocks are valid too. > + } > + > + return block; > + > +err: > + kfree(block); > + return NULL; > +} > + > +static int ge_b850v3_lvds_dp_get_modes(struct drm_connector *connector) > +{ > + struct ge_b850v3_lvds_dp *ptn_bridge; Why are the bridge pointers named ptn_bridge? I'm guessing it's because you used nxp-ptn3460 bridge driver as reference. You should use something relevant to your device. > + struct i2c_client *client; > + int num_modes = 0; > + > + ptn_bridge = connector_to_ge_b850v3_lvds_dp(connector); > + client = ptn_bridge->edid_i2c; > + > + mutex_lock(&ptn_bridge->edid_mutex); Do we really need this mutex? All the paths that call a connector's get_modes hold the drm device's dev->mode_config.mutex lock anyway. > + > + kfree(ptn_bridge->edid); > + ptn_bridge->edid = (struct edid *) stdp2690_get_edid(client); > + > + if (ptn_bridge->edid) { > + drm_mode_connector_update_edid_property(connector, > + ptn_bridge->edid); > + num_modes = drm_add_edid_modes(connector, ptn_bridge->edid); > + } > + > + mutex_unlock(&ptn_bridge->edid_mutex); > + > + return num_modes; > +} > + > + > +static enum drm_mode_status ge_b850v3_lvds_dp_mode_valid( > + struct drm_connector *connector, struct drm_display_mode *mode) > +{ > + return MODE_OK; > +} > + > +static const struct > +drm_connector_helper_funcs ge_b850v3_lvds_dp_connector_helper_funcs = { > + .get_modes = ge_b850v3_lvds_dp_get_modes, > + .mode_valid = ge_b850v3_lvds_dp_mode_valid, > +}; > + > +static enum drm_connector_status ge_b850v3_lvds_dp_detect( > + struct drm_connector *connector, bool force) > +{ > + struct ge_b850v3_lvds_dp *ptn_bridge = > + connector_to_ge_b850v3_lvds_dp(connector); > + struct i2c_client *ge_b850v3_lvds_dp_i2c = > + ptn_bridge->ge_b850v3_lvds_dp_i2c; > + s32 link_state; > + > + link_state = i2c_smbus_read_word_data(ge_b850v3_lvds_dp_i2c, > + STDP4028_DPTX_STS_REG); > + > + if (link_state == STDP4028_CON_STATE_CONNECTED) > + return connector_status_connected; > + > + if (link_state == 0) > + return connector_status_disconnected; > + > + return connector_status_unknown; > +} > + > +static const struct drm_connector_funcs ge_b850v3_lvds_dp_connector_funcs = { > + .dpms = drm_atomic_helper_connector_dpms, > + .fill_modes = drm_helper_probe_single_connector_modes, > + .detect = ge_b850v3_lvds_dp_detect, > + .destroy = drm_connector_cleanup, > + .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 irqreturn_t ge_b850v3_lvds_dp_irq_handler(int irq, void *dev_id) > +{ > + struct ge_b850v3_lvds_dp *ptn_bridge = dev_id; > + struct i2c_client *ge_b850v3_lvds_dp_i2c > + = ptn_bridge->ge_b850v3_lvds_dp_i2c; > + > + mutex_lock(&ptn_bridge->irq_reg_mutex); Do we need this mutex? The handler is registered with the IRQF_ONESHOT flag, so we won't get another interrupt until this handler returns. > + > + i2c_smbus_write_word_data(ge_b850v3_lvds_dp_i2c, > + STDP4028_DPTX_IRQ_STS_REG, STDP4028_DPTX_IRQ_CLEAR); > + > + mutex_unlock(&ptn_bridge->irq_reg_mutex); > + > + if (ptn_bridge->connector.dev) > + drm_kms_helper_hotplug_event(ptn_bridge->connector.dev); > + > + return IRQ_HANDLED; > +} > + > +static int ge_b850v3_lvds_dp_attach(struct drm_bridge *bridge) > +{ > + struct ge_b850v3_lvds_dp *ptn_bridge > + = bridge_to_ge_b850v3_lvds_dp(bridge); > + struct drm_connector *connector = &ptn_bridge->connector; > + struct i2c_client *ge_b850v3_lvds_dp_i2c > + = ptn_bridge->ge_b850v3_lvds_dp_i2c; > + int ret; > + > + if (!bridge->encoder) { > + DRM_ERROR("Parent encoder object not found"); > + return -ENODEV; > + } > + > + connector->polled = DRM_CONNECTOR_POLL_HPD; > + > + drm_connector_helper_add(connector, > + &ge_b850v3_lvds_dp_connector_helper_funcs); > + > + ret = drm_connector_init(bridge->dev, connector, > + &ge_b850v3_lvds_dp_connector_funcs, > + DRM_MODE_CONNECTOR_DisplayPort); > + if (ret) { > + DRM_ERROR("Failed to initialize connector with drm\n"); > + return ret; > + } > + > + ret = drm_mode_connector_attach_encoder(connector, bridge->encoder); > + if (ret) > + return ret; > + > + drm_helper_hpd_irq_event(connector->dev); This call doesn't serve any purpose for a connector until it is registered. You can drop this. > + > + /* Configures the bridge to re-enable interrupts after each ack. */ > + i2c_smbus_write_word_data(ge_b850v3_lvds_dp_i2c, > + STDP4028_IRQ_OUT_CONF_REG, STDP4028_DPTX_DP_IRQ_EN); > + > + /* Enable interrupts */ > + i2c_smbus_write_word_data(ge_b850v3_lvds_dp_i2c, > + STDP4028_DPTX_IRQ_EN_REG, STDP4028_DPTX_IRQ_CONFIG); > + > + return 0; > +} > + > +static void ge_b850v3_lvds_dp_detach(struct drm_bridge *bridge) > +{ > + struct ge_b850v3_lvds_dp *ptn_bridge > + = bridge_to_ge_b850v3_lvds_dp(bridge); > + struct i2c_client *ge_b850v3_lvds_dp_i2c > + = ptn_bridge->ge_b850v3_lvds_dp_i2c; > + > + /* Disable interrupts */ > + i2c_smbus_write_word_data(ge_b850v3_lvds_dp_i2c, > + STDP4028_DPTX_IRQ_EN_REG, ~STDP4028_DPTX_IRQ_CONFIG); > +} > + > +static const struct drm_bridge_funcs ge_b850v3_lvds_dp_funcs = { > + .attach = ge_b850v3_lvds_dp_attach, > + .detach = ge_b850v3_lvds_dp_detach, > +}; > + > +static int ge_b850v3_lvds_dp_probe(struct i2c_client *ge_b850v3_lvds_dp_i2c, > + const struct i2c_device_id *id) > +{ > + struct device *dev = &ge_b850v3_lvds_dp_i2c->dev; > + struct ge_b850v3_lvds_dp *ptn_bridge; > + > + ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL); > + if (!ptn_bridge) > + return -ENOMEM; > + > + mutex_init(&ptn_bridge->edid_mutex); > + mutex_init(&ptn_bridge->irq_reg_mutex); > + > + ptn_bridge->ge_b850v3_lvds_dp_i2c = ge_b850v3_lvds_dp_i2c; > + ptn_bridge->bridge.driver_private = ptn_bridge; bridge->driver_private isn't used by the driver anywhere. It's probably better to drop it until it is used. > + i2c_set_clientdata(ge_b850v3_lvds_dp_i2c, ptn_bridge); > + > + ptn_bridge->edid_i2c = i2c_new_secondary_device(ge_b850v3_lvds_dp_i2c, > + DEFAULT_EDID_REG_NAME, DEFAULT_EDID_REG); > + > + if (!ptn_bridge->edid_i2c) { > + dev_err(dev, "Error registering edid i2c_client, aborting...\n"); > + return -ENODEV; > + } > + > + ptn_bridge->bridge.funcs = &ge_b850v3_lvds_dp_funcs; > + ptn_bridge->bridge.of_node = dev->of_node; > + drm_bridge_add(&ptn_bridge->bridge); > + > + /* Clear pending interrupts since power up. */ > + i2c_smbus_write_word_data(ge_b850v3_lvds_dp_i2c, > + STDP4028_DPTX_IRQ_STS_REG, STDP4028_DPTX_IRQ_CLEAR); > + > + if (!ge_b850v3_lvds_dp_i2c->irq) > + return 0; > + > + return devm_request_threaded_irq(&ge_b850v3_lvds_dp_i2c->dev, > + ge_b850v3_lvds_dp_i2c->irq, NULL, > + ge_b850v3_lvds_dp_irq_handler, > + IRQF_TRIGGER_HIGH | IRQF_ONESHOT, > + "ge-b850v3-lvds-dp", ptn_bridge); > +} > + > +static int ge_b850v3_lvds_dp_remove(struct i2c_client *ge_b850v3_lvds_dp_i2c) > +{ > + struct ge_b850v3_lvds_dp *ptn_bridge = > + i2c_get_clientdata(ge_b850v3_lvds_dp_i2c); > + > + i2c_unregister_device(ptn_bridge->edid_i2c); > + > + drm_bridge_remove(&ptn_bridge->bridge); > + > + kfree(ptn_bridge->edid); > + > + return 0; > +} > + > +static const struct i2c_device_id ge_b850v3_lvds_dp_i2c_table[] = { > + {"b850v3-lvds-dp", 0}, > + {}, > +}; > +MODULE_DEVICE_TABLE(i2c, ge_b850v3_lvds_dp_i2c_table); > + > +static const struct of_device_id ge_b850v3_lvds_dp_match[] = { > + { .compatible = "ge,b850v3-lvds-dp" }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, ge_b850v3_lvds_dp_match); > + > +static struct i2c_driver ge_b850v3_lvds_dp_driver = { > + .id_table = ge_b850v3_lvds_dp_i2c_table, > + .probe = ge_b850v3_lvds_dp_probe, > + .remove = ge_b850v3_lvds_dp_remove, > + .driver = { > + .name = "b850v3-lvds-dp", > + .of_match_table = ge_b850v3_lvds_dp_match, > + }, > +}; > +module_i2c_driver(ge_b850v3_lvds_dp_driver); > + > +MODULE_AUTHOR("Peter Senna Tschudin "); > +MODULE_AUTHOR("Martyn Welch "); > +MODULE_DESCRIPTION("GE LVDS to DP++ display bridge)"); > +MODULE_LICENSE("GPL v2"); > -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project