Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753734AbbKBLfL (ORCPT ); Mon, 2 Nov 2015 06:35:11 -0500 Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:44497 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753484AbbKBLfI (ORCPT ); Mon, 2 Nov 2015 06:35:08 -0500 Message-ID: <1446464084.3442.36.camel@pengutronix.de> Subject: Re: [RFC v2 2/2] drm/bridge: Add I2C based driver for ps8640 bridge From: Philipp Zabel To: jitao shi Cc: Rob Herring , Ian Campbell , Kumar Gala , David Airlie , Matthias Brugger , Thierry Reding , Ajay Kumar , Inki Dae , Rahul Sharma , Sean Paul , Vincent Palatin , Andy Yan , Russell King , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, srv_heupstream@mediatek.com, Sascha Hauer , yingjoe.chen@mediatek.com, eddie.huang@mediatek.com, cawa.cheng@mediatek.com, bibby.hsieh@mediatek.com, Pawel Moll , Mark Rutland , ck.hu@mediatek.com Date: Mon, 02 Nov 2015 12:34:44 +0100 In-Reply-To: <1446436496.8671.2.camel@mszsdhlt06> References: <1446430166-7378-1-git-send-email-jitao.shi@mediatek.com> <1446430166-7378-2-git-send-email-jitao.shi@mediatek.com> <1446436496.8671.2.camel@mszsdhlt06> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.9-1+b1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 2001:67c:670:100:96de:80ff:fec2:9969 X-SA-Exim-Mail-From: p.zabel@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 13053 Lines: 441 Hi Jitao, a few comments below. Am Montag, den 02.11.2015, 11:54 +0800 schrieb jitao shi: [...] > > +static int ps8640_check_valid_id(struct ps8640 *ps_bridge) This could be bool and return true/false. > > +{ > > + struct i2c_client *client = ps_bridge->client; > > + u8 rev_id_low, rev_id_high, chip_id_low, chip_id_high; > > + int retry_cnt = 0; > > + > > + do { > > + ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_CHIP_H, > > + &chip_id_high); > > + if (chip_id_high != 0x30) > > + DRM_INFO("chip_id_high = 0x%x\n", chip_id_high); > > + } while ((retry_cnt++ < 2) && (chip_id_high != 0x30)); > > + > > + ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_REV_L, &rev_id_low); > > + ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_REV_H, &rev_id_high); > > + ps8640_regr(client, ps_bridge->base_reg + 4, PAGE4_CHIP_L, > > + &chip_id_low); > > + > > + if ((rev_id_low == 0x00) && (rev_id_high == 0x0a) && > > + (chip_id_low == 0x00) && (chip_id_high == 0x30)) > > + return 1; > > + > > + return 0; > > +} > > + > > +static void ps8640_show_mcu_fw_version(struct ps8640 *ps_bridge) > > +{ > > + struct i2c_client *client = ps_bridge->client; > > + u8 major_ver, minor_ver; > > + > > + ps8640_regr(client, ps_bridge->base_reg + 5, 0x4, &major_ver); > > + ps8640_regr(client, ps_bridge->base_reg + 5, 0x5, &minor_ver); > > + > > + DRM_INFO_ONCE("ps8640 rom fw version %d.%d\n", major_ver, minor_ver); > > +} > > + > > +static int ps8640_bdg_enable(struct ps8640 *ps_bridge) > > +{ > > + struct i2c_client *client = ps_bridge->client; > > + > > + if (ps8640_check_valid_id(ps_bridge)) { > > + ps8640_regw(client, ps_bridge->base_reg + 3, 0xfe, 0x13); > > + ps8640_regw(client, ps_bridge->base_reg + 3, 0xff, 0x18); > > + ps8640_regw(client, ps_bridge->base_reg + 3, 0xfe, 0x13); > > + ps8640_regw(client, ps_bridge->base_reg + 3, 0xff, 0x1c); Can you introduce #defines with descriptive names for those magic constants and register offsets, and maybe also i2c address offsets? > > + > > + return 0; > > + } > > + > > + return -1; Never return -1 to signal a problem. If there was an error, use a proper error code. > > +} > > + > > +static void ps8640_prepare(struct ps8640 *ps_bridge) > > +{ > > + struct i2c_client *client = ps_bridge->client; > > + int err, retry_cnt = 0; > > + u8 set_vdo_done; > > + > > + if (ps_bridge->enabled) > > + return; > > + > > + if (drm_panel_prepare(ps_bridge->panel)) { > > + DRM_ERROR("failed to prepare panel\n"); > > + return; > > + } > > + > > + err = regulator_enable(ps_bridge->pwr_1v2_supply); > > + if (err < 0) { > > + DRM_ERROR("failed to enable pwr_1v2_supply: %d\n", err); Missing panel unprepare. > > + return; > > + } > > + > > + err = regulator_enable(ps_bridge->pwr_3v3_supply); > > + if (err < 0) { > > + DRM_ERROR("failed to enable pwr_3v3_supply: %d\n", err); Missing panel unprepare and vdd12 regulator disable. > > + return; > > + } > > + > > + gpiod_set_value(ps_bridge->gpio_slp_n, 1); > > + gpiod_set_value(ps_bridge->gpio_rst_n, 0); > > + usleep_range(500, 700); > > + gpiod_set_value(ps_bridge->gpio_rst_n, 1); > > + > > + do { > > + msleep(50); > > + ps8640_regr(client, ps_bridge->base_reg + 2, PAGE2_GPIO_H, > > + &set_vdo_done); > > + } while ((retry_cnt++ < 70) && ((set_vdo_done & PS_GPIO9) != PS_GPIO9)); > > + > > + ps8640_show_mcu_fw_version(ps_bridge); > > + ps_bridge->enabled = true; > > +} > > + > > +static void ps8640_pre_enable(struct drm_bridge *bridge) > > +{ > > + struct ps8640 *ps_bridge = bridge_to_ps8640(bridge); > > + > > + ps8640_prepare(ps_bridge); > > +} > > + > > +static void ps8640_enable(struct drm_bridge *bridge) > > +{ > > + struct ps8640 *ps_bridge = bridge_to_ps8640(bridge); > > + > > + ps8640_bdg_enable(ps_bridge); > > + > > + if (drm_panel_enable(ps_bridge->panel)) { > > + DRM_ERROR("failed to enable panel\n"); > > + return; The return is superfluous. > > + } > > +} > > + > > +static void ps8640_disable(struct drm_bridge *bridge) > > +{ > > + struct ps8640 *ps_bridge = bridge_to_ps8640(bridge); > > + > > + if (!ps_bridge->enabled) > > + return; > > + > > + ps_bridge->enabled = false; > > + > > + if (drm_panel_disable(ps_bridge->panel)) { > > + DRM_ERROR("failed to disable panel\n"); > > + return; Shouldn't we still disable the bridge, even if panel disable fails? > > + } > > + > > + regulator_disable(ps_bridge->pwr_1v2_supply); > > + regulator_disable(ps_bridge->pwr_3v3_supply); > > + gpiod_set_value(ps_bridge->gpio_rst_n, 0); > > + gpiod_set_value(ps_bridge->gpio_slp_n, 0); > > +} > > + > > +static void ps8640_post_disable(struct drm_bridge *bridge) > > +{ > > + struct ps8640 *ps_bridge = bridge_to_ps8640(bridge); > > + > > + if (drm_panel_unprepare(ps_bridge->panel)) { > > + DRM_ERROR("failed to unprepare panel\n"); > > + return; Drop the return. > > + } > > +} > > + > > +static int ps8640_get_modes(struct drm_connector *connector) > > +{ > > + struct ps8640 *ps_bridge = connector_to_ps8640(connector); > > + struct i2c_client *client = ps_bridge->client; > > + > > + ps8640_prepare(ps_bridge); > > + ps8640_regw(client, ps_bridge->base_reg + 2, 0xea, 0xd0); > > + > > + return drm_panel_get_modes(ps_bridge->panel); > > +} > > + > > +static struct drm_encoder *ps8640_best_encoder(struct drm_connector *connector) > > +{ > > + struct ps8640 *ps_bridge; > > + > > + ps_bridge = connector_to_ps8640(connector); > > + return ps_bridge->bridge.encoder; > > +} > > + > > +static const struct drm_connector_helper_funcs > > + ps8640_connector_helper_funcs = { > > + .get_modes = ps8640_get_modes, > > + .best_encoder = ps8640_best_encoder, > > +}; > > + > > +static enum drm_connector_status ps8640_detect(struct drm_connector *connector, > > + bool force) > > +{ > > + return connector_status_connected; > > +} > > + > > +static void ps8640_connector_destroy(struct drm_connector *connector) > > +{ > > + drm_connector_unregister(connector); > > + drm_connector_cleanup(connector); > > +} > > + > > +static const struct drm_connector_funcs ps8640_connector_funcs = { > > + .dpms = drm_atomic_helper_connector_dpms, > > + .fill_modes = drm_helper_probe_single_connector_modes, > > + .detect = ps8640_detect, > > + .destroy = ps8640_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, > > +}; > > + > > +int ps8640_bridge_attach(struct drm_bridge *bridge) > > +{ > > + struct ps8640 *ps_bridge = bridge_to_ps8640(bridge); > > + int ret; > > + > > + if (!bridge->encoder) { > > + DRM_ERROR("Parent encoder object not found"); > > + return -ENODEV; > > + } > > + > > + ret = drm_connector_init(bridge->dev, &ps_bridge->connector, > > + &ps8640_connector_funcs, > > + DRM_MODE_CONNECTOR_eDP); > > + > > + if (ret) { > > + DRM_ERROR("Failed to initialize connector with drm\n"); > > + return ret; > > + } > > + > > + drm_connector_helper_add(&ps_bridge->connector, > > + &ps8640_connector_helper_funcs); > > + drm_connector_register(&ps_bridge->connector); > > + > > + ps_bridge->connector.dpms = DRM_MODE_DPMS_ON; > > + drm_mode_connector_attach_encoder(&ps_bridge->connector, > > + bridge->encoder); > > + > > + if (ps_bridge->panel) > > + drm_panel_attach(ps_bridge->panel, &ps_bridge->connector); > > + > > + return ret; > > +} > > + > > +static bool ps8640_bridge_mode_fixup(struct drm_bridge *bridge, > > + const struct drm_display_mode *mode, > > + struct drm_display_mode *adjusted_mode) > > +{ > > + return true; > > +} > > + > > +static const struct drm_bridge_funcs ps8640_bridge_funcs = { > > + .attach = ps8640_bridge_attach, > > + .mode_fixup = ps8640_bridge_mode_fixup, > > + .disable = ps8640_disable, > > + .post_disable = ps8640_post_disable, > > + .pre_enable = ps8640_pre_enable, > > + .enable = ps8640_enable, > > +}; > > + > > +static int ps8640_probe(struct i2c_client *client, > > + const struct i2c_device_id *id) > > +{ > > + struct device *dev = &client->dev; > > + struct ps8640 *ps_bridge; > > + struct device_node *np = dev->of_node; > > + struct device_node *in_ep, *out_ep; > > + struct device_node *panel_node = NULL; > > + int ret; > > + u32 temp_reg; > > + > > + ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL); > > + if (!ps_bridge) > > + return -ENOMEM; > > + > > + in_ep = of_graph_get_next_endpoint(np, NULL); > > + if (in_ep) { > > + out_ep = of_graph_get_next_endpoint(np, in_ep); Better use: port = of_graph_get_port_by_id(np, 1); out_ep = of_get_child_by_name(port, "endpoint"); > > + of_node_put(in_ep); > > + if (out_ep) { > > + panel_node = of_graph_get_remote_port_parent(out_ep); > > + of_node_put(out_ep); > > + } > > + } > > + if (panel_node) { > > + ps_bridge->panel = of_drm_find_panel(panel_node); > > + of_node_put(panel_node); > > + if (!ps_bridge->panel) > > + return -EPROBE_DEFER; > > + } > > + > > + ps_bridge->client = client; > > + > > + ps_bridge->pwr_3v3_supply = devm_regulator_get(dev, "vdd33-supply"); > > + if (IS_ERR(ps_bridge->pwr_3v3_supply)) { > > + dev_err(dev, "cannot get ps_bridge->pwr_3v3_supply\n"); Instead of printing the variable name, just say "vdd3-supply". Also, it is good practice to print the actual error value. > > + return PTR_ERR(ps_bridge->pwr_3v3_supply); > > + } > > + > > + ps_bridge->pwr_1v2_supply = devm_regulator_get(dev, "vdd12-supply"); > > + if (IS_ERR(ps_bridge->pwr_1v2_supply)) { > > + dev_err(dev, "cannot get ps_bridge->pwr_1v2_supply\n"); Same as above. > > + return PTR_ERR(ps_bridge->pwr_1v2_supply); > > + } > > + > > + ps_bridge->gpio_mode_sel_n = devm_gpiod_get(&client->dev, "mode-sel", > > + GPIOD_OUT_HIGH); > > + if (IS_ERR(ps_bridge->gpio_mode_sel_n)) { > > + ret = PTR_ERR(ps_bridge->gpio_mode_sel_n); > > + DRM_ERROR("cannot get gpio_mode_sel_n %d\n", ret); It would be better to use dev_err instead of DRM_ERROR. The same applies to the DRM_ERRORs below. > > + return ret; > > + } > > + > > + ret = gpiod_direction_output(ps_bridge->gpio_mode_sel_n, 1); > > + if (ret) { > > + DRM_ERROR("cannot configure gpio_mode_sel_n\n"); > > + return ret; > > + } > > + > > + ps_bridge->gpio_slp_n = devm_gpiod_get(&client->dev, "sleep-gpios", > > + GPIOD_OUT_HIGH); > > + if (IS_ERR(ps_bridge->gpio_slp_n)) { > > + ret = PTR_ERR(ps_bridge->gpio_slp_n); > > + DRM_ERROR("cannot get gpio_slp_n %d\n", ret); > > + return ret; > > + } > > + > > + ret = gpiod_direction_output(ps_bridge->gpio_slp_n, 1); > > + if (ret) { > > + DRM_ERROR("cannot configure gpio_slp_n\n"); > > + return ret; > > + } > > + > > + ps_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset", > > + GPIOD_OUT_HIGH); > > + if (IS_ERR(ps_bridge->gpio_rst_n)) { > > + ret = PTR_ERR(ps_bridge->gpio_rst_n); > > + DRM_ERROR("cannot get gpio_rst_n %d\n", ret); > > + return ret; > > + } > > + > > + ret = gpiod_direction_output(ps_bridge->gpio_rst_n, 1); > > + if (ret) { > > + DRM_ERROR("cannot configure gpio_rst_n\n"); > > + return ret; > > + } > > + > > + ret = of_property_read_u32(dev->of_node, "reg", &temp_reg); > > + if (ret) { > > + DRM_ERROR("Can't read base_reg value\n"); > > + return ret; > > + } > > + ps_bridge->base_reg = temp_reg; No need for this, the i2c address is already stored in client->addr. > > + ps_bridge->bridge.funcs = &ps8640_bridge_funcs; > > + ps_bridge->bridge.of_node = dev->of_node; > > + ret = drm_bridge_add(&ps_bridge->bridge); > > + if (ret) { > > + DRM_ERROR("Failed to add bridge\n"); > > + return ret; > > + } > > + > > + i2c_set_clientdata(client, ps_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 i2c_device_id ps8640_i2c_table[] = { > > + {"parade,ps8640", 0}, > > + {}, > > +}; > > +MODULE_DEVICE_TABLE(i2c, ps8640_i2c_table); > > + > > +static const struct of_device_id ps8640_match[] = { > > + { .compatible = "parade,ps8640" }, > > + {}, > > +}; > > +MODULE_DEVICE_TABLE(of, ps8640_match); > > + > > +static struct i2c_driver ps8640_driver = { > > + .id_table = ps8640_i2c_table, > > + .probe = ps8640_probe, > > + .remove = ps8640_remove, > > + .driver = { > > + .name = "parade,ps8640", > > + .owner = THIS_MODULE, > > + .of_match_table = ps8640_match, > > + }, > > +}; > > +module_i2c_driver(ps8640_driver); > > + > > +MODULE_AUTHOR("Jitao Shi "); > > +MODULE_AUTHOR("CK Hu "); > > +MODULE_DESCRIPTION("PARADE ps8640 DSI-eDP converter driver"); > > +MODULE_LICENSE("GPL v2"); best regards Philipp -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/