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path: root/drivers/platform/chrome/cros_ec_lpc.c
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Diffstat (limited to 'drivers/platform/chrome/cros_ec_lpc.c')
-rw-r--r--drivers/platform/chrome/cros_ec_lpc.c165
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);