1 files changed, 135 insertions, 30 deletions

diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c
index c9c240fbe7c6..2c44c7f3322a 100644
--- a/drivers/platform/chrome/cros_ec_lpc.c
+++ b/drivers/platform/chrome/cros_ec_lpc.c
@@ -23,7 +23,7 @@
 #include <linux/printk.h>
 #include <linux/suspend.h>
 
-#include "cros_ec_lpc_reg.h"
+#include "cros_ec_lpc_mec.h"
 
 #define DRV_NAME "cros_ec_lpcs"
 #define ACPI_DRV_NAME "GOOG0004"
@@ -31,6 +31,96 @@
 /* True if ACPI device is present */
 static bool cros_ec_lpc_acpi_device_found;
 
+/**
+ * struct lpc_driver_ops - LPC driver operations
+ * @read: Copy length bytes from EC address offset into buffer dest. Returns
+ *        the 8-bit checksum of all bytes read.
+ * @write: Copy length bytes from buffer msg into EC address offset. Returns
+ *         the 8-bit checksum of all bytes written.
+ */
+struct lpc_driver_ops {
+	u8 (*read)(unsigned int offset, unsigned int length, u8 *dest);
+	u8 (*write)(unsigned int offset, unsigned int length, const u8 *msg);
+};
+
+static struct lpc_driver_ops cros_ec_lpc_ops = { };
+
+/*
+ * A generic instance of the read function of struct lpc_driver_ops, used for
+ * the LPC EC.
+ */
+static u8 cros_ec_lpc_read_bytes(unsigned int offset, unsigned int length,
+				 u8 *dest)
+{
+	int sum = 0;
+	int i;
+
+	for (i = 0; i < length; ++i) {
+		dest[i] = inb(offset + i);
+		sum += dest[i];
+	}
+
+	/* Return checksum of all bytes read */
+	return sum;
+}
+
+/*
+ * A generic instance of the write function of struct lpc_driver_ops, used for
+ * the LPC EC.
+ */
+static u8 cros_ec_lpc_write_bytes(unsigned int offset, unsigned int length,
+				  const u8 *msg)
+{
+	int sum = 0;
+	int i;
+
+	for (i = 0; i < length; ++i) {
+		outb(msg[i], offset + i);
+		sum += msg[i];
+	}
+
+	/* Return checksum of all bytes written */
+	return sum;
+}
+
+/*
+ * An instance of the read function of struct lpc_driver_ops, used for the
+ * MEC variant of LPC EC.
+ */
+static u8 cros_ec_lpc_mec_read_bytes(unsigned int offset, unsigned int length,
+				     u8 *dest)
+{
+	int in_range = cros_ec_lpc_mec_in_range(offset, length);
+
+	if (in_range < 0)
+		return 0;
+
+	return in_range ?
+		cros_ec_lpc_io_bytes_mec(MEC_IO_READ,
+					 offset - EC_HOST_CMD_REGION0,
+					 length, dest) :
+		cros_ec_lpc_read_bytes(offset, length, dest);
+}
+
+/*
+ * An instance of the write function of struct lpc_driver_ops, used for the
+ * MEC variant of LPC EC.
+ */
+static u8 cros_ec_lpc_mec_write_bytes(unsigned int offset, unsigned int length,
+				      const u8 *msg)
+{
+	int in_range = cros_ec_lpc_mec_in_range(offset, length);
+
+	if (in_range < 0)
+		return 0;
+
+	return in_range ?
+		cros_ec_lpc_io_bytes_mec(MEC_IO_WRITE,
+					 offset - EC_HOST_CMD_REGION0,
+					 length, (u8 *)msg) :
+		cros_ec_lpc_write_bytes(offset, length, msg);
+}
+
 static int ec_response_timed_out(void)
 {
 	unsigned long one_second = jiffies + HZ;
@@ -38,7 +128,7 @@ static int ec_response_timed_out(void)
 
 	usleep_range(200, 300);
 	do {
-		if (!(cros_ec_lpc_read_bytes(EC_LPC_ADDR_HOST_CMD, 1, &data) &
+		if (!(cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_CMD, 1, &data) &
 		    EC_LPC_STATUS_BUSY_MASK))
 			return 0;
 		usleep_range(100, 200);
@@ -58,11 +148,11 @@ static int cros_ec_pkt_xfer_lpc(struct cros_ec_device *ec,
 	ret = cros_ec_prepare_tx(ec, msg);
 
 	/* Write buffer */
-	cros_ec_lpc_write_bytes(EC_LPC_ADDR_HOST_PACKET, ret, ec->dout);
+	cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_PACKET, ret, ec->dout);
 
 	/* Here we go */
 	sum = EC_COMMAND_PROTOCOL_3;
-	cros_ec_lpc_write_bytes(EC_LPC_ADDR_HOST_CMD, 1, &sum);
+	cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_CMD, 1, &sum);
 
 	if (ec_response_timed_out()) {
 		dev_warn(ec->dev, "EC responsed timed out\n");
@@ -71,15 +161,15 @@ static int cros_ec_pkt_xfer_lpc(struct cros_ec_device *ec,
 	}
 
 	/* Check result */
-	msg->result = cros_ec_lpc_read_bytes(EC_LPC_ADDR_HOST_DATA, 1, &sum);
+	msg->result = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_DATA, 1, &sum);
 	ret = cros_ec_check_result(ec, msg);
 	if (ret)
 		goto done;
 
 	/* Read back response */
 	dout = (u8 *)&response;
-	sum = cros_ec_lpc_read_bytes(EC_LPC_ADDR_HOST_PACKET, sizeof(response),
-				     dout);
+	sum = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_PACKET, sizeof(response),
+				   dout);
 
 	msg->result = response.result;
 
@@ -92,9 +182,9 @@ static int cros_ec_pkt_xfer_lpc(struct cros_ec_device *ec,
 	}
 
 	/* Read response and process checksum */
-	sum += cros_ec_lpc_read_bytes(EC_LPC_ADDR_HOST_PACKET +
-				      sizeof(response), response.data_len,
-				      msg->data);
+	sum += cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_PACKET +
+				    sizeof(response), response.data_len,
+				    msg->data);
 
 	if (sum) {
 		dev_err(ec->dev,
@@ -134,17 +224,17 @@ static int cros_ec_cmd_xfer_lpc(struct cros_ec_device *ec,
 	sum = msg->command + args.flags + args.command_version + args.data_size;
 
 	/* Copy data and update checksum */
-	sum += cros_ec_lpc_write_bytes(EC_LPC_ADDR_HOST_PARAM, msg->outsize,
-				       msg->data);
+	sum += cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_PARAM, msg->outsize,
+				     msg->data);
 
 	/* Finalize checksum and write args */
 	args.checksum = sum;
-	cros_ec_lpc_write_bytes(EC_LPC_ADDR_HOST_ARGS, sizeof(args),
-				(u8 *)&args);
+	cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_ARGS, sizeof(args),
+			      (u8 *)&args);
 
 	/* Here we go */
 	sum = msg->command;
-	cros_ec_lpc_write_bytes(EC_LPC_ADDR_HOST_CMD, 1, &sum);
+	cros_ec_lpc_ops.write(EC_LPC_ADDR_HOST_CMD, 1, &sum);
 
 	if (ec_response_timed_out()) {
 		dev_warn(ec->dev, "EC responsed timed out\n");
@@ -153,14 +243,13 @@ static int cros_ec_cmd_xfer_lpc(struct cros_ec_device *ec,
 	}
 
 	/* Check result */
-	msg->result = cros_ec_lpc_read_bytes(EC_LPC_ADDR_HOST_DATA, 1, &sum);
+	msg->result = cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_DATA, 1, &sum);
 	ret = cros_ec_check_result(ec, msg);
 	if (ret)
 		goto done;
 
 	/* Read back args */
-	cros_ec_lpc_read_bytes(EC_LPC_ADDR_HOST_ARGS, sizeof(args),
-			       (u8 *)&args);
+	cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_ARGS, sizeof(args), (u8 *)&args);
 
 	if (args.data_size > msg->insize) {
 		dev_err(ec->dev,
@@ -174,8 +263,8 @@ static int cros_ec_cmd_xfer_lpc(struct cros_ec_device *ec,
 	sum = msg->command + args.flags + args.command_version + args.data_size;
 
 	/* Read response and update checksum */
-	sum += cros_ec_lpc_read_bytes(EC_LPC_ADDR_HOST_PARAM, args.data_size,
-				      msg->data);
+	sum += cros_ec_lpc_ops.read(EC_LPC_ADDR_HOST_PARAM, args.data_size,
+				    msg->data);
 
 	/* Verify checksum */
 	if (args.checksum != sum) {
@@ -205,13 +294,13 @@ static int cros_ec_lpc_readmem(struct cros_ec_device *ec, unsigned int offset,
 
 	/* fixed length */
 	if (bytes) {
-		cros_ec_lpc_read_bytes(EC_LPC_ADDR_MEMMAP + offset, bytes, s);
+		cros_ec_lpc_ops.read(EC_LPC_ADDR_MEMMAP + offset, bytes, s);
 		return bytes;
 	}
 
 	/* string */
 	for (; i < EC_MEMMAP_SIZE; i++, s++) {
-		cros_ec_lpc_read_bytes(EC_LPC_ADDR_MEMMAP + i, 1, s);
+		cros_ec_lpc_ops.read(EC_LPC_ADDR_MEMMAP + i, 1, s);
 		cnt++;
 		if (!*s)
 			break;
@@ -248,10 +337,25 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
 		return -EBUSY;
 	}
 
-	cros_ec_lpc_read_bytes(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID, 2, buf);
+	/*
+	 * Read the mapped ID twice, the first one is assuming the
+	 * EC is a Microchip Embedded Controller (MEC) variant, if the
+	 * protocol fails, fallback to the non MEC variant and try to
+	 * read again the ID.
+	 */
+	cros_ec_lpc_ops.read = cros_ec_lpc_mec_read_bytes;
+	cros_ec_lpc_ops.write = cros_ec_lpc_mec_write_bytes;
+	cros_ec_lpc_ops.read(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID, 2, buf);
 	if (buf[0] != 'E' || buf[1] != 'C') {
-		dev_err(dev, "EC ID not detected\n");
-		return -ENODEV;
+		/* Re-assign read/write operations for the non MEC variant */
+		cros_ec_lpc_ops.read = cros_ec_lpc_read_bytes;
+		cros_ec_lpc_ops.write = cros_ec_lpc_write_bytes;
+		cros_ec_lpc_ops.read(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID, 2,
+				     buf);
+		if (buf[0] != 'E' || buf[1] != 'C') {
+			dev_err(dev, "EC ID not detected\n");
+			return -ENODEV;
+		}
 	}
 
 	if (!devm_request_region(dev, EC_HOST_CMD_REGION0,
@@ -405,7 +509,7 @@ static int cros_ec_lpc_resume(struct device *dev)
 }
 #endif
 
-const struct dev_pm_ops cros_ec_lpc_pm_ops = {
+static const struct dev_pm_ops cros_ec_lpc_pm_ops = {
 	SET_LATE_SYSTEM_SLEEP_PM_OPS(cros_ec_lpc_suspend, cros_ec_lpc_resume)
 };
 
@@ -446,13 +550,14 @@ static int __init cros_ec_lpc_init(void)
 		return -ENODEV;
 	}
 
-	cros_ec_lpc_reg_init();
+	cros_ec_lpc_mec_init(EC_HOST_CMD_REGION0,
+			     EC_LPC_ADDR_MEMMAP + EC_MEMMAP_SIZE);
 
 	/* Register the driver */
 	ret = platform_driver_register(&cros_ec_lpc_driver);
 	if (ret) {
 		pr_err(DRV_NAME ": can't register driver: %d\n", ret);
-		cros_ec_lpc_reg_destroy();
+		cros_ec_lpc_mec_destroy();
 		return ret;
 	}
 
@@ -462,7 +567,7 @@ static int __init cros_ec_lpc_init(void)
 		if (ret) {
 			pr_err(DRV_NAME ": can't register device: %d\n", ret);
 			platform_driver_unregister(&cros_ec_lpc_driver);
-			cros_ec_lpc_reg_destroy();
+			cros_ec_lpc_mec_destroy();
 		}
 	}
 
@@ -474,7 +579,7 @@ static void __exit cros_ec_lpc_exit(void)
 	if (!cros_ec_lpc_acpi_device_found)
 		platform_device_unregister(&cros_ec_lpc_device);
 	platform_driver_unregister(&cros_ec_lpc_driver);
-	cros_ec_lpc_reg_destroy();
+	cros_ec_lpc_mec_destroy();
 }
 
 module_init(cros_ec_lpc_init);