347 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * NXP PTN3460 DP/LVDS bridge driver4 *5 * Copyright (C) 2013 Google, Inc.6 */7 8#include <linux/delay.h>9#include <linux/gpio/consumer.h>10#include <linux/i2c.h>11#include <linux/module.h>12#include <linux/of.h>13#include <drm/drm_atomic_helper.h>14#include <drm/drm_bridge.h>15#include <drm/drm_crtc.h>16#include <drm/drm_edid.h>17#include <drm/drm_of.h>18#include <drm/drm_panel.h>19#include <drm/drm_print.h>20#include <drm/drm_probe_helper.h>21 22#define PTN3460_EDID_ADDR 0x023#define PTN3460_EDID_EMULATION_ADDR 0x8424#define PTN3460_EDID_ENABLE_EMULATION 025#define PTN3460_EDID_EMULATION_SELECTION 126#define PTN3460_EDID_SRAM_LOAD_ADDR 0x8527 28struct ptn3460_bridge {29 struct drm_connector connector;30 struct i2c_client *client;31 struct drm_bridge bridge;32 struct drm_bridge *panel_bridge;33 struct gpio_desc *gpio_pd_n;34 struct gpio_desc *gpio_rst_n;35 u32 edid_emulation;36 bool enabled;37};38 39static inline struct ptn3460_bridge *40 bridge_to_ptn3460(struct drm_bridge *bridge)41{42 return container_of(bridge, struct ptn3460_bridge, bridge);43}44 45static inline struct ptn3460_bridge *46 connector_to_ptn3460(struct drm_connector *connector)47{48 return container_of(connector, struct ptn3460_bridge, connector);49}50 51static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr,52 u8 *buf, int len)53{54 int ret;55 56 ret = i2c_master_send(ptn_bridge->client, &addr, 1);57 if (ret < 0) {58 DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);59 return ret;60 }61 62 ret = i2c_master_recv(ptn_bridge->client, buf, len);63 if (ret < 0) {64 DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret);65 return ret;66 }67 68 return 0;69}70 71static int ptn3460_write_byte(struct ptn3460_bridge *ptn_bridge, char addr,72 char val)73{74 int ret;75 char buf[2];76 77 buf[0] = addr;78 buf[1] = val;79 80 ret = i2c_master_send(ptn_bridge->client, buf, ARRAY_SIZE(buf));81 if (ret < 0) {82 DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);83 return ret;84 }85 86 return 0;87}88 89static int ptn3460_select_edid(struct ptn3460_bridge *ptn_bridge)90{91 int ret;92 char val;93 94 /* Load the selected edid into SRAM (accessed at PTN3460_EDID_ADDR) */95 ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_SRAM_LOAD_ADDR,96 ptn_bridge->edid_emulation);97 if (ret) {98 DRM_ERROR("Failed to transfer EDID to sram, ret=%d\n", ret);99 return ret;100 }101 102 /* Enable EDID emulation and select the desired EDID */103 val = 1 << PTN3460_EDID_ENABLE_EMULATION |104 ptn_bridge->edid_emulation << PTN3460_EDID_EMULATION_SELECTION;105 106 ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_EMULATION_ADDR, val);107 if (ret) {108 DRM_ERROR("Failed to write EDID value, ret=%d\n", ret);109 return ret;110 }111 112 return 0;113}114 115static void ptn3460_pre_enable(struct drm_bridge *bridge)116{117 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);118 int ret;119 120 if (ptn_bridge->enabled)121 return;122 123 gpiod_set_value(ptn_bridge->gpio_pd_n, 1);124 125 gpiod_set_value(ptn_bridge->gpio_rst_n, 0);126 usleep_range(10, 20);127 gpiod_set_value(ptn_bridge->gpio_rst_n, 1);128 129 /*130 * There's a bug in the PTN chip where it falsely asserts hotplug before131 * it is fully functional. We're forced to wait for the maximum start up132 * time specified in the chip's datasheet to make sure we're really up.133 */134 msleep(90);135 136 ret = ptn3460_select_edid(ptn_bridge);137 if (ret)138 DRM_ERROR("Select EDID failed ret=%d\n", ret);139 140 ptn_bridge->enabled = true;141}142 143static void ptn3460_disable(struct drm_bridge *bridge)144{145 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);146 147 if (!ptn_bridge->enabled)148 return;149 150 ptn_bridge->enabled = false;151 152 gpiod_set_value(ptn_bridge->gpio_rst_n, 1);153 gpiod_set_value(ptn_bridge->gpio_pd_n, 0);154}155 156 157static const struct drm_edid *ptn3460_edid_read(struct drm_bridge *bridge,158 struct drm_connector *connector)159{160 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);161 const struct drm_edid *drm_edid = NULL;162 bool power_off;163 u8 *edid;164 int ret;165 166 power_off = !ptn_bridge->enabled;167 ptn3460_pre_enable(&ptn_bridge->bridge);168 169 edid = kmalloc(EDID_LENGTH, GFP_KERNEL);170 if (!edid) {171 DRM_ERROR("Failed to allocate EDID\n");172 goto out;173 }174 175 ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid,176 EDID_LENGTH);177 if (ret) {178 kfree(edid);179 goto out;180 }181 182 drm_edid = drm_edid_alloc(edid, EDID_LENGTH);183 184out:185 if (power_off)186 ptn3460_disable(&ptn_bridge->bridge);187 188 return drm_edid;189}190 191static int ptn3460_connector_get_modes(struct drm_connector *connector)192{193 struct ptn3460_bridge *ptn_bridge = connector_to_ptn3460(connector);194 const struct drm_edid *drm_edid;195 int num_modes;196 197 drm_edid = ptn3460_edid_read(&ptn_bridge->bridge, connector);198 drm_edid_connector_update(connector, drm_edid);199 num_modes = drm_edid_connector_add_modes(connector);200 drm_edid_free(drm_edid);201 202 return num_modes;203}204 205static const struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = {206 .get_modes = ptn3460_connector_get_modes,207};208 209static const struct drm_connector_funcs ptn3460_connector_funcs = {210 .fill_modes = drm_helper_probe_single_connector_modes,211 .destroy = drm_connector_cleanup,212 .reset = drm_atomic_helper_connector_reset,213 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,214 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,215};216 217static int ptn3460_bridge_attach(struct drm_bridge *bridge,218 enum drm_bridge_attach_flags flags)219{220 struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);221 int ret;222 223 /* Let this driver create connector if requested */224 ret = drm_bridge_attach(bridge->encoder, ptn_bridge->panel_bridge,225 bridge, flags | DRM_BRIDGE_ATTACH_NO_CONNECTOR);226 if (ret < 0)227 return ret;228 229 if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)230 return 0;231 232 ptn_bridge->connector.polled = DRM_CONNECTOR_POLL_HPD;233 ret = drm_connector_init(bridge->dev, &ptn_bridge->connector,234 &ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS);235 if (ret) {236 DRM_ERROR("Failed to initialize connector with drm\n");237 return ret;238 }239 drm_connector_helper_add(&ptn_bridge->connector,240 &ptn3460_connector_helper_funcs);241 drm_connector_register(&ptn_bridge->connector);242 drm_connector_attach_encoder(&ptn_bridge->connector,243 bridge->encoder);244 245 drm_helper_hpd_irq_event(ptn_bridge->connector.dev);246 247 return ret;248}249 250static const struct drm_bridge_funcs ptn3460_bridge_funcs = {251 .pre_enable = ptn3460_pre_enable,252 .disable = ptn3460_disable,253 .attach = ptn3460_bridge_attach,254 .edid_read = ptn3460_edid_read,255};256 257static int ptn3460_probe(struct i2c_client *client)258{259 struct device *dev = &client->dev;260 struct ptn3460_bridge *ptn_bridge;261 struct drm_bridge *panel_bridge;262 int ret;263 264 ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL);265 if (!ptn_bridge) {266 return -ENOMEM;267 }268 269 panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0);270 if (IS_ERR(panel_bridge))271 return PTR_ERR(panel_bridge);272 273 ptn_bridge->panel_bridge = panel_bridge;274 ptn_bridge->client = client;275 276 ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown",277 GPIOD_OUT_HIGH);278 if (IS_ERR(ptn_bridge->gpio_pd_n)) {279 ret = PTR_ERR(ptn_bridge->gpio_pd_n);280 dev_err(dev, "cannot get gpio_pd_n %d\n", ret);281 return ret;282 }283 284 /*285 * Request the reset pin low to avoid the bridge being286 * initialized prematurely287 */288 ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset",289 GPIOD_OUT_LOW);290 if (IS_ERR(ptn_bridge->gpio_rst_n)) {291 ret = PTR_ERR(ptn_bridge->gpio_rst_n);292 DRM_ERROR("cannot get gpio_rst_n %d\n", ret);293 return ret;294 }295 296 ret = of_property_read_u32(dev->of_node, "edid-emulation",297 &ptn_bridge->edid_emulation);298 if (ret) {299 dev_err(dev, "Can't read EDID emulation value\n");300 return ret;301 }302 303 ptn_bridge->bridge.funcs = &ptn3460_bridge_funcs;304 ptn_bridge->bridge.ops = DRM_BRIDGE_OP_EDID;305 ptn_bridge->bridge.type = DRM_MODE_CONNECTOR_LVDS;306 ptn_bridge->bridge.of_node = dev->of_node;307 drm_bridge_add(&ptn_bridge->bridge);308 309 i2c_set_clientdata(client, ptn_bridge);310 311 return 0;312}313 314static void ptn3460_remove(struct i2c_client *client)315{316 struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client);317 318 drm_bridge_remove(&ptn_bridge->bridge);319}320 321static const struct i2c_device_id ptn3460_i2c_table[] = {322 {"ptn3460", 0},323 {},324};325MODULE_DEVICE_TABLE(i2c, ptn3460_i2c_table);326 327static const struct of_device_id ptn3460_match[] = {328 { .compatible = "nxp,ptn3460" },329 {},330};331MODULE_DEVICE_TABLE(of, ptn3460_match);332 333static struct i2c_driver ptn3460_driver = {334 .id_table = ptn3460_i2c_table,335 .probe = ptn3460_probe,336 .remove = ptn3460_remove,337 .driver = {338 .name = "nxp,ptn3460",339 .of_match_table = ptn3460_match,340 },341};342module_i2c_driver(ptn3460_driver);343 344MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>");345MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver");346MODULE_LICENSE("GPL v2");347