1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2020 Marek Vasut <marex@denx.de>
  4 *
  5 * Based on tc358764.c by
  6 *  Andrzej Hajda <a.hajda@samsung.com>
  7 *  Maciej Purski <m.purski@samsung.com>
  8 *
  9 * Based on rpi_touchscreen.c by
 10 *  Eric Anholt <eric@anholt.net>
 11 */
 12
 13#include <linux/delay.h>
 14#include <linux/mod_devicetable.h>
 15#include <linux/module.h>
 16#include <linux/of_graph.h>
 17#include <linux/regulator/consumer.h>
 18
 19#include <video/mipi_display.h>
 20
 21#include <drm/drm_atomic_helper.h>
 22#include <drm/drm_crtc.h>
 23#include <drm/drm_mipi_dsi.h>
 24#include <drm/drm_of.h>
 25#include <drm/drm_panel.h>
 26#include <drm/drm_print.h>
 27#include <drm/drm_probe_helper.h>
 28
 29/* PPI layer registers */
 30#define PPI_STARTPPI		0x0104 /* START control bit */
 31#define PPI_LPTXTIMECNT		0x0114 /* LPTX timing signal */
 32#define PPI_D0S_ATMR		0x0144
 33#define PPI_D1S_ATMR		0x0148
 34#define PPI_D0S_CLRSIPOCOUNT	0x0164 /* Assertion timer for Lane 0 */
 35#define PPI_D1S_CLRSIPOCOUNT	0x0168 /* Assertion timer for Lane 1 */
 36#define PPI_START_FUNCTION	1
 37
 38/* DSI layer registers */
 39#define DSI_STARTDSI		0x0204 /* START control bit of DSI-TX */
 40#define DSI_LANEENABLE		0x0210 /* Enables each lane */
 41#define DSI_RX_START		1
 42
 43/* LCDC/DPI Host Registers */
 44#define LCDCTRL			0x0420
 45
 46/* SPI Master Registers */
 47#define SPICMR			0x0450
 48#define SPITCR			0x0454
 49
 50/* System Controller Registers */
 51#define SYSCTRL			0x0464
 52
 53/* System registers */
 54#define LPX_PERIOD		3
 55
 56/* Lane enable PPI and DSI register bits */
 57#define LANEENABLE_CLEN		BIT(0)
 58#define LANEENABLE_L0EN		BIT(1)
 59#define LANEENABLE_L1EN		BIT(2)
 60
 61struct tc358762 {
 62	struct device *dev;
 63	struct drm_bridge bridge;
 64	struct regulator *regulator;
 65	struct drm_bridge *panel_bridge;
 66	bool pre_enabled;
 67	int error;
 68};
 69
 70static int tc358762_clear_error(struct tc358762 *ctx)
 71{
 72	int ret = ctx->error;
 73
 74	ctx->error = 0;
 75	return ret;
 76}
 77
 78static void tc358762_write(struct tc358762 *ctx, u16 addr, u32 val)
 79{
 80	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
 81	ssize_t ret;
 82	u8 data[6];
 83
 84	if (ctx->error)
 85		return;
 86
 87	data[0] = addr;
 88	data[1] = addr >> 8;
 89	data[2] = val;
 90	data[3] = val >> 8;
 91	data[4] = val >> 16;
 92	data[5] = val >> 24;
 93
 94	ret = mipi_dsi_generic_write(dsi, data, sizeof(data));
 95	if (ret < 0)
 96		ctx->error = ret;
 97}
 98
 99static inline struct tc358762 *bridge_to_tc358762(struct drm_bridge *bridge)
100{
101	return container_of(bridge, struct tc358762, bridge);
102}
103
104static int tc358762_init(struct tc358762 *ctx)
105{
106	tc358762_write(ctx, DSI_LANEENABLE,
107		       LANEENABLE_L0EN | LANEENABLE_CLEN);
108	tc358762_write(ctx, PPI_D0S_CLRSIPOCOUNT, 5);
109	tc358762_write(ctx, PPI_D1S_CLRSIPOCOUNT, 5);
110	tc358762_write(ctx, PPI_D0S_ATMR, 0);
111	tc358762_write(ctx, PPI_D1S_ATMR, 0);
112	tc358762_write(ctx, PPI_LPTXTIMECNT, LPX_PERIOD);
113
114	tc358762_write(ctx, SPICMR, 0x00);
115	tc358762_write(ctx, LCDCTRL, 0x00100150);
116	tc358762_write(ctx, SYSCTRL, 0x040f);
117	msleep(100);
118
119	tc358762_write(ctx, PPI_STARTPPI, PPI_START_FUNCTION);
120	tc358762_write(ctx, DSI_STARTDSI, DSI_RX_START);
121
122	msleep(100);
123
124	return tc358762_clear_error(ctx);
125}
126
127static void tc358762_post_disable(struct drm_bridge *bridge)
128{
129	struct tc358762 *ctx = bridge_to_tc358762(bridge);
130	int ret;
131
132	/*
133	 * The post_disable hook might be called multiple times.
134	 * We want to avoid regulator imbalance below.
135	 */
136	if (!ctx->pre_enabled)
137		return;
138
139	ctx->pre_enabled = false;
140
141	ret = regulator_disable(ctx->regulator);
142	if (ret < 0)
143		dev_err(ctx->dev, "error disabling regulators (%d)\n", ret);
144}
145
146static void tc358762_pre_enable(struct drm_bridge *bridge)
147{
148	struct tc358762 *ctx = bridge_to_tc358762(bridge);
149	int ret;
150
151	ret = regulator_enable(ctx->regulator);
152	if (ret < 0)
153		dev_err(ctx->dev, "error enabling regulators (%d)\n", ret);
154
155	ret = tc358762_init(ctx);
156	if (ret < 0)
157		dev_err(ctx->dev, "error initializing bridge (%d)\n", ret);
158
159	ctx->pre_enabled = true;
160}
161
162static int tc358762_attach(struct drm_bridge *bridge,
163			   enum drm_bridge_attach_flags flags)
164{
165	struct tc358762 *ctx = bridge_to_tc358762(bridge);
166
167	return drm_bridge_attach(bridge->encoder, ctx->panel_bridge,
168				 bridge, flags);
169}
170
171static const struct drm_bridge_funcs tc358762_bridge_funcs = {
172	.post_disable = tc358762_post_disable,
173	.pre_enable = tc358762_pre_enable,
174	.attach = tc358762_attach,
175};
176
177static int tc358762_parse_dt(struct tc358762 *ctx)
178{
179	struct drm_bridge *panel_bridge;
180	struct device *dev = ctx->dev;
181
182	panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0);
183	if (IS_ERR(panel_bridge))
184		return PTR_ERR(panel_bridge);
185
186	ctx->panel_bridge = panel_bridge;
187
188	return 0;
189}
190
191static int tc358762_configure_regulators(struct tc358762 *ctx)
192{
193	ctx->regulator = devm_regulator_get(ctx->dev, "vddc");
194	if (IS_ERR(ctx->regulator))
195		return PTR_ERR(ctx->regulator);
196
197	return 0;
198}
199
200static int tc358762_probe(struct mipi_dsi_device *dsi)
201{
202	struct device *dev = &dsi->dev;
203	struct tc358762 *ctx;
204	int ret;
205
206	ctx = devm_kzalloc(dev, sizeof(struct tc358762), GFP_KERNEL);
207	if (!ctx)
208		return -ENOMEM;
209
210	mipi_dsi_set_drvdata(dsi, ctx);
211
212	ctx->dev = dev;
213	ctx->pre_enabled = false;
214
215	/* TODO: Find out how to get dual-lane mode working */
216	dsi->lanes = 1;
217	dsi->format = MIPI_DSI_FMT_RGB888;
218	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
219			  MIPI_DSI_MODE_LPM;
220
221	ret = tc358762_parse_dt(ctx);
222	if (ret < 0)
223		return ret;
224
225	ret = tc358762_configure_regulators(ctx);
226	if (ret < 0)
227		return ret;
228
229	ctx->bridge.funcs = &tc358762_bridge_funcs;
230	ctx->bridge.type = DRM_MODE_CONNECTOR_DPI;
231	ctx->bridge.of_node = dev->of_node;
232
233	drm_bridge_add(&ctx->bridge);
234
235	ret = mipi_dsi_attach(dsi);
236	if (ret < 0) {
237		drm_bridge_remove(&ctx->bridge);
238		dev_err(dev, "failed to attach dsi\n");
239	}
240
241	return ret;
242}
243
244static void tc358762_remove(struct mipi_dsi_device *dsi)
245{
246	struct tc358762 *ctx = mipi_dsi_get_drvdata(dsi);
247
248	mipi_dsi_detach(dsi);
249	drm_bridge_remove(&ctx->bridge);
250}
251
252static const struct of_device_id tc358762_of_match[] = {
253	{ .compatible = "toshiba,tc358762" },
254	{ }
255};
256MODULE_DEVICE_TABLE(of, tc358762_of_match);
257
258static struct mipi_dsi_driver tc358762_driver = {
259	.probe = tc358762_probe,
260	.remove = tc358762_remove,
261	.driver = {
262		.name = "tc358762",
263		.of_match_table = tc358762_of_match,
264	},
265};
266module_mipi_dsi_driver(tc358762_driver);
267
268MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
269MODULE_DESCRIPTION("MIPI-DSI based Driver for TC358762 DSI/DPI Bridge");
270MODULE_LICENSE("GPL v2");