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2023-12-11 072de836f53be56a70cecf70b43ae43b7ce17376 
 kernel/drivers/input/touchscreen/raydium_i2c_ts.c
....@@ -1,17 +1,8 @@
1
+// SPDX-License-Identifier: GPL-2.0-only
12 /*
23  * Raydium touchscreen I2C driver.
34  *
45  * Copyright (C) 2012-2014, Raydium Semiconductor Corporation.
5
- *
6
- * This program is free software; you can redistribute it and/or
7
- * modify it under the terms of the GNU General Public License
8
- * version 2, and only version 2, as published by the
9
- * Free Software Foundation.
10
- *
11
- * This program is distributed in the hope that it will be useful,
12
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
13
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14
- * GNU General Public License for more details.
156  *
167  * Raydium reserves the right to make changes without further notice
178  * to the materials described herein. Raydium does not assume any
....@@ -60,6 +51,7 @@
6051 
6152 /* Touch relative info */
6253 #define RM_MAX_RETRIES		3
54
+#define RM_RETRY_DELAY_MS	20
6355 #define RM_MAX_TOUCH_NUM	10
6456 #define RM_BOOT_DELAY_MS	100
6557 
....@@ -145,83 +137,134 @@
145137 	bool wake_irq_enabled;
146138 };
147139 
148
-static int raydium_i2c_send(struct i2c_client *client,
149
-			    u8 addr, const void *data, size_t len)
150
-{
151
-	u8 *buf;
152
-	int tries = 0;
153
-	int ret;
140
+/*
141
+ * Header to be sent for RM_CMD_BANK_SWITCH command. This is used by
142
+ * raydium_i2c_{read|send} below.
143
+ */
144
+struct __packed raydium_bank_switch_header {
145
+	u8 cmd;
146
+	__be32 be_addr;
147
+};
154148 
155
-	buf = kmalloc(len + 1, GFP_KERNEL);
156
-	if (!buf)
149
+static int raydium_i2c_xfer(struct i2c_client *client, u32 addr,
150
+			    struct i2c_msg *xfer, size_t xfer_count)
151
+{
152
+	int ret;
153
+	/*
154
+	 * If address is greater than 255, then RM_CMD_BANK_SWITCH needs to be
155
+	 * sent first. Else, skip the header i.e. xfer[0].
156
+	 */
157
+	int xfer_start_idx = (addr > 0xff) ? 0 : 1;
158
+	xfer_count -= xfer_start_idx;
159
+
160
+	ret = i2c_transfer(client->adapter, &xfer[xfer_start_idx], xfer_count);
161
+	if (likely(ret == xfer_count))
162
+		return 0;
163
+
164
+	return ret < 0 ? ret : -EIO;
165
+}
166
+
167
+static int raydium_i2c_send(struct i2c_client *client,
168
+			    u32 addr, const void *data, size_t len)
169
+{
170
+	int tries = 0;
171
+	int error;
172
+	u8 *tx_buf;
173
+	u8 reg_addr = addr & 0xff;
174
+
175
+	tx_buf = kmalloc(len + 1, GFP_KERNEL);
176
+	if (!tx_buf)
157177 		return -ENOMEM;
158178 
159
-	buf[0] = addr;
160
-	memcpy(buf + 1, data, len);
179
+	tx_buf[0] = reg_addr;
180
+	memcpy(tx_buf + 1, data, len);
161181 
162182 	do {
163
-		ret = i2c_master_send(client, buf, len + 1);
164
-		if (likely(ret == len + 1))
165
-			break;
183
+		struct raydium_bank_switch_header header = {
184
+			.cmd = RM_CMD_BANK_SWITCH,
185
+			.be_addr = cpu_to_be32(addr),
186
+		};
166187 
167
-		msleep(20);
188
+		/*
189
+		 * Perform as a single i2c_transfer transaction to ensure that
190
+		 * no other I2C transactions are initiated on the bus to any
191
+		 * other device in between. Initiating transacations to other
192
+		 * devices after RM_CMD_BANK_SWITCH is sent is known to cause
193
+		 * issues. This is also why regmap infrastructure cannot be used
194
+		 * for this driver. Regmap handles page(bank) switch and reads
195
+		 * as separate i2c_transfer() operations. This can result in
196
+		 * problems if the Raydium device is on a shared I2C bus.
197
+		 */
198
+		struct i2c_msg xfer[] = {
199
+			{
200
+				.addr = client->addr,
201
+				.len = sizeof(header),
202
+				.buf = (u8 *)&header,
203
+			},
204
+			{
205
+				.addr = client->addr,
206
+				.len = len + 1,
207
+				.buf = tx_buf,
208
+			},
209
+		};
210
+
211
+		error = raydium_i2c_xfer(client, addr, xfer, ARRAY_SIZE(xfer));
212
+		if (likely(!error))
213
+			goto out;
214
+
215
+		msleep(RM_RETRY_DELAY_MS);
168216 	} while (++tries < RM_MAX_RETRIES);
169217 
170
-	kfree(buf);
171
-
172
-	if (unlikely(ret != len + 1)) {
173
-		if (ret >= 0)
174
-			ret = -EIO;
175
-		dev_err(&client->dev, "%s failed: %d\n", __func__, ret);
176
-		return ret;
177
-	}
178
-
179
-	return 0;
218
+	dev_err(&client->dev, "%s failed: %d\n", __func__, error);
219
+out:
220
+	kfree(tx_buf);
221
+	return error;
180222 }
181223 
182224 static int raydium_i2c_read(struct i2c_client *client,
183
-			    u8 addr, void *data, size_t len)
225
+			    u32 addr, void *data, size_t len)
184226 {
185
-	struct i2c_msg xfer[] = {
186
-		{
187
-			.addr = client->addr,
188
-			.len = 1,
189
-			.buf = &addr,
190
-		},
191
-		{
192
-			.addr = client->addr,
193
-			.flags = I2C_M_RD,
194
-			.len = len,
195
-			.buf = data,
196
-		}
197
-	};
198
-	int ret;
199
-
200
-	ret = i2c_transfer(client->adapter, xfer, ARRAY_SIZE(xfer));
201
-	if (unlikely(ret != ARRAY_SIZE(xfer)))
202
-		return ret < 0 ? ret : -EIO;
203
-
204
-	return 0;
205
-}
206
-
207
-static int raydium_i2c_read_message(struct i2c_client *client,
208
-				    u32 addr, void *data, size_t len)
209
-{
210
-	__be32 be_addr;
211
-	size_t xfer_len;
212227 	int error;
213228 
214229 	while (len) {
215
-		xfer_len = min_t(size_t, len, RM_MAX_READ_SIZE);
230
+		u8 reg_addr = addr & 0xff;
231
+		struct raydium_bank_switch_header header = {
232
+			.cmd = RM_CMD_BANK_SWITCH,
233
+			.be_addr = cpu_to_be32(addr),
234
+		};
235
+		size_t xfer_len = min_t(size_t, len, RM_MAX_READ_SIZE);
216236 
217
-		be_addr = cpu_to_be32(addr);
237
+		/*
238
+		 * Perform as a single i2c_transfer transaction to ensure that
239
+		 * no other I2C transactions are initiated on the bus to any
240
+		 * other device in between. Initiating transacations to other
241
+		 * devices after RM_CMD_BANK_SWITCH is sent is known to cause
242
+		 * issues. This is also why regmap infrastructure cannot be used
243
+		 * for this driver. Regmap handles page(bank) switch and writes
244
+		 * as separate i2c_transfer() operations. This can result in
245
+		 * problems if the Raydium device is on a shared I2C bus.
246
+		 */
247
+		struct i2c_msg xfer[] = {
248
+			{
249
+				.addr = client->addr,
250
+				.len = sizeof(header),
251
+				.buf = (u8 *)&header,
252
+			},
253
+			{
254
+				.addr = client->addr,
255
+				.len = 1,
256
+				.buf = &reg_addr,
257
+			},
258
+			{
259
+				.addr = client->addr,
260
+				.len = xfer_len,
261
+				.buf = data,
262
+				.flags = I2C_M_RD,
263
+			}
264
+		};
218265 
219
-		error = raydium_i2c_send(client, RM_CMD_BANK_SWITCH,
220
-					 &be_addr, sizeof(be_addr));
221
-		if (!error)
222
-			error = raydium_i2c_read(client, addr & 0xff,
223
-						 data, xfer_len);
224
-		if (error)
266
+		error = raydium_i2c_xfer(client, addr, xfer, ARRAY_SIZE(xfer));
267
+		if (unlikely(error))
225268 			return error;
226269 
227270 		len -= xfer_len;
....@@ -232,27 +275,13 @@
232275 	return 0;
233276 }
234277 
235
-static int raydium_i2c_send_message(struct i2c_client *client,
236
-				    u32 addr, const void *data, size_t len)
237
-{
238
-	__be32 be_addr = cpu_to_be32(addr);
239
-	int error;
240
-
241
-	error = raydium_i2c_send(client, RM_CMD_BANK_SWITCH,
242
-				 &be_addr, sizeof(be_addr));
243
-	if (!error)
244
-		error = raydium_i2c_send(client, addr & 0xff, data, len);
245
-
246
-	return error;
247
-}
248
-
249278 static int raydium_i2c_sw_reset(struct i2c_client *client)
250279 {
251280 	const u8 soft_rst_cmd = 0x01;
252281 	int error;
253282 
254
-	error = raydium_i2c_send_message(client, RM_RESET_MSG_ADDR,
255
-					 &soft_rst_cmd, sizeof(soft_rst_cmd));
283
+	error = raydium_i2c_send(client, RM_RESET_MSG_ADDR, &soft_rst_cmd,
284
+				 sizeof(soft_rst_cmd));
256285 	if (error) {
257286 		dev_err(&client->dev, "software reset failed: %d\n", error);
258287 		return error;
....@@ -304,9 +333,8 @@
304333 		if (error)
305334 			continue;
306335 
307
-		error = raydium_i2c_read_message(client,
308
-						 le32_to_cpu(query_bank_addr),
309
-						 &ts->info, sizeof(ts->info));
336
+		error = raydium_i2c_read(client, le32_to_cpu(query_bank_addr),
337
+					 &ts->info, sizeof(ts->info));
310338 		if (error)
311339 			continue;
312340 
....@@ -844,8 +872,8 @@
844872 	if (ts->boot_mode != RAYDIUM_TS_MAIN)
845873 		goto out;
846874 
847
-	error = raydium_i2c_read_message(ts->client, ts->data_bank_addr,
848
-					 ts->report_data, ts->pkg_size);
875
+	error = raydium_i2c_read(ts->client, ts->data_bank_addr,
876
+				 ts->report_data, ts->pkg_size);
849877 	if (error)
850878 		goto out;
851879