ectool: Remove CROS_EC_DEV_IOCRDMEM

On !LPC EC, we can read memory via CROS_EC_DEV_IOCXCMD ioctl,
using command EC_CMD_READ_MEMMAP.
On platform that supports direct memory access (lpc), we access
the memory directly, bypassing the ioctl.

BUG=chromium:602832
TEST=On gnawty and veyron, check 'ectool battery' works.
Verify that gnawty use io mapped registers.
BRANCH=none

Change-Id: I9bfcddcf450bf8df63ead78e1df97dd7392289e6
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/338853
Reviewed-by: Randall Spangler <rspangler@chromium.org>

util/comm-dev.c

@@ -91,31 +91,6 @@ static int ec_command_dev(int command, int version,
 	return r;
 }
 
-static int ec_readmem_dev(int offset, int bytes, void *dest)
-{
-	struct cros_ec_readmem s_mem;
-	struct ec_params_read_memmap r_mem;
-	int r;
-	static int fake_it;
-
-	if (!fake_it) {
-		s_mem.offset = offset;
-		s_mem.bytes = bytes;
-		s_mem.buffer = dest;
-		r = ioctl(fd, CROS_EC_DEV_IOCRDMEM, &s_mem);
-		if (r < 0 && errno == ENOTTY)
-			fake_it = 1;
-		else
-			return r;
-	}
-
-	r_mem.offset = offset;
-	r_mem.size = bytes;
-	return ec_command_dev(EC_CMD_READ_MEMMAP, 0,
-			      &r_mem, sizeof(r_mem),
-			      dest, bytes);
-}
-
 /* New ioctl format, used by Chrome OS 4.4 and later as well as upstream 4.0+ */
 
 static int ec_command_dev_v2(int command, int version,
@@ -156,8 +131,6 @@ static int ec_command_dev_v2(int command, int version,
 	} else {
 		memcpy(indata, s_cmd->data, MIN(r, insize));
 		if (s_cmd->result != EC_RES_SUCCESS) {
-			fprintf(stderr, "EC result %d (%s)\n", s_cmd->result,
-				strresult(s_cmd->result));
 			r =  -EECRESULT - s_cmd->result;
 		}
 	}
@@ -166,31 +139,6 @@ static int ec_command_dev_v2(int command, int version,
 	return r;
 }
 
-static int ec_readmem_dev_v2(int offset, int bytes, void *dest)
-{
-	struct cros_ec_readmem_v2 s_mem;
-	struct ec_params_read_memmap r_mem;
-	int r;
-	static int fake_it;
-
-	if (!fake_it) {
-		s_mem.offset = offset;
-		s_mem.bytes = bytes;
-		r = ioctl(fd, CROS_EC_DEV_IOCRDMEM_V2, &s_mem);
-		if (r < 0 && errno == ENOTTY) {
-			fake_it = 1;
-		} else {
-			memcpy(dest, s_mem.buffer, bytes);
-			return r;
-		}
-	}
-
-	r_mem.offset = offset;
-	r_mem.size = bytes;
-	return ec_command_dev(EC_CMD_READ_MEMMAP, 0,
-			      &r_mem, sizeof(r_mem),
-			      dest, bytes);
-}
 
 /*
  * Attempt to communicate with kernel using old ioctl format.
@@ -221,7 +169,6 @@ static int ec_dev_is_v2(void)
 
 int comm_init_dev(const char *device_name)
 {
-	int (*ec_cmd_readmem)(int offset, int bytes, void *dest);
 	char version[80];
 	char device[80] = "/dev/";
 	int r;
@@ -248,15 +195,20 @@ int comm_init_dev(const char *device_name)
 
 	if (ec_dev_is_v2()) {
 		ec_command_proto = ec_command_dev_v2;
-		ec_cmd_readmem = ec_readmem_dev_v2;
 	} else {
 		ec_command_proto = ec_command_dev;
-		ec_cmd_readmem = ec_readmem_dev;
 	}
 
-	if (ec_cmd_readmem(EC_MEMMAP_ID, 2, version) == 2 &&
+	if (ec_readmem(EC_MEMMAP_ID, 2, version) < 0) {
-	    version[0] == 'E' && version[1] == 'C')
+		/*
-		ec_readmem = ec_cmd_readmem;
+		 * Unable to read memory map through command protocol,
+		 * assume LPC transport underneath.
+		 */
+		comm_init_lpc(1);
+		if (ec_readmem(EC_MEMMAP_ID, 2, version) < 0)
+			fprintf(stderr,
+				"Unable to read memory mapped registers.\n");
+	}
 
 	/*
 	 * Set temporary size, will be updated later.

util/comm-host.c

@@ -25,10 +25,6 @@ void *ec_outbuf;
 void *ec_inbuf;
 static int command_offset;
 
-int comm_init_dev(const char *device_name) __attribute__((weak));
-int comm_init_lpc(void) __attribute__((weak));
-int comm_init_i2c(void) __attribute__((weak));
-
 static int fake_readmem(int offset, int bytes, void *dest)
 {
 	struct ec_params_read_memmap p;
@@ -92,16 +88,15 @@ int comm_init(int interfaces, const char *device_name)
 	}
 
 	/* Prefer new /dev method */
-	if ((interfaces & COMM_DEV) && comm_init_dev &&
+	if ((interfaces & COMM_DEV) && !comm_init_dev(device_name))
-	    !comm_init_dev(device_name))
 		goto init_ok;
 
 	/* Fallback to direct LPC on x86 */
-	if ((interfaces & COMM_LPC) && comm_init_lpc && !comm_init_lpc())
+	if ((interfaces & COMM_LPC) && !comm_init_lpc(0))
 		goto init_ok;
 
 	/* Fallback to direct i2c on ARM */
-	if ((interfaces & COMM_I2C) && comm_init_i2c && !comm_init_i2c())
+	if ((interfaces & COMM_I2C) && !comm_init_i2c())
 		goto init_ok;
 
 	/* Give up */

util/comm-host.h

@@ -74,4 +74,15 @@ extern int (*ec_command_proto)(int command, int version,
  */
 extern int (*ec_readmem)(int offset, int bytes, void *dest);
 
+/*
+ * Functions for initializing communication protocols.
+ * @param device_name: device name to open to access the ec.
+ * @param init_readmem_only:
+ *  1: init only ec_readmem
+ *  0: set ec_command_proto as well.
+ */
+int comm_init_dev(const char *device_name);
+int comm_init_lpc(int init_readmem_only);
+int comm_init_i2c(void);
+
 #endif /* __UTIL_COMM_HOST_H */

util/comm-lpc.c

@@ -246,7 +246,7 @@ static int ec_readmem_lpc(int offset, int bytes, void *dest)
 	return cnt;
 }
 
-int comm_init_lpc(void)
+int comm_init_lpc(int init_readmem_only)
 {
 	int i;
 	int byte = 0xff;
@@ -257,6 +257,13 @@ int comm_init_lpc(void)
 		return -3;
 	}
 
+	ec_readmem = ec_readmem_lpc;
+
+	if (init_readmem_only) {
+		/* Function to send commands already defined. */
+		return 0;
+	}
+
 	/*
 	 * Test if the I/O port has been configured for Chromium EC LPC
 	 * interface.  Chromium EC guarantees that at least one status bit will
@@ -308,9 +315,13 @@ int comm_init_lpc(void)
 		return -5;
 	}
 
-	/* Either one supports reading mapped memory directly. */
-	ec_readmem = ec_readmem_lpc;
 	return 0;
 }
 
-#endif
+#else  /* defined(__i386__) || defined(__x86_64__) */
+#include <errno.h>
+int comm_init_lpc(int unused)
+{
+	return -EOPNOTSUPP;
+}
+#endif  /* defined(__i386__) || defined(__x86_64__) */