[U-Boot] [PATCH] mii: add read-modify-write option to mii command

[Tim James]

When accessing PHY registers it is often desirable to only update
selected bits, so it is necessary to first read the current value
before writing back an modified value with the relevant bits
updated.  

To simplify this and to allow such operations to be incorporated 
into simple shell scripts propose adding a 'modify' option to the
existing mii command, which takes a mask indicating the bits to 
be updated in addition to a data value containing the new bits,
ie, <updated> = (<data> & <mask>) | (<current> & ~<mask>).

Signed-off-by: Tim James <tim.james at macltd.com>
Cc: Nobuhiro Iwamatsu <iwamatsu at nigauri.org>

---

--- a/common/cmd_mii.c
+++ b/common/cmd_mii.c
@@ -249,6 +249,7 @@
 static uint last_addr_hi;
 static uint last_reg_lo;
 static uint last_reg_hi;
+static uint last_mask;
 
 static void extract_range(
 	char * input,
@@ -272,7 +273,7 @@
 	char		op[2];
 	unsigned char	addrlo, addrhi, reglo, reghi;
 	unsigned char	addr, reg;
-	unsigned short	data;
+	unsigned short	data, mask;
 	int		rcode = 0;
 	const char	*devname;
 
@@ -294,6 +295,7 @@
 	reglo  = last_reg_lo;
 	reghi  = last_reg_hi;
 	data   = last_data;
+	mask   = last_mask;
 
 	if ((flag & CMD_FLAG_REPEAT) == 0) {
 		op[0] = argv[1][0];
@@ -308,6 +310,8 @@
 			extract_range(argv[3], &reglo, &reghi);
 		if (argc >= 5)
 			data = simple_strtoul (argv[4], NULL, 16);
+		if (argc >= 6)
+			mask = simple_strtoul (argv[5], NULL, 16);
 	}
 
 	/* use current device */
@@ -375,6 +379,24 @@
 				}
 			}
 		}
+	} else if (op[0] == 'm') {
+		for (addr = addrlo; addr <= addrhi; addr++) {
+			for (reg = reglo; reg <= reghi; reg++) {
+				unsigned short current = 0;
+				if (miiphy_read (devname, addr, reg, &current) != 0) {
+					printf("Error reading from the PHY addr=%02x reg=%02x\n",
+						addr, reg);
+					rcode = 1;
+				} else {
+					unsigned short updated = (data & mask) | (current & ~mask);
+					if (miiphy_write (devname, addr, reg, 0xFFFF & updated) != 0) {
+						printf("Error writing to the PHY addr=%02x reg=%02x\n",
+							addr, reg);
+						rcode = 1;
+					}
+				}
+			}
+		}
 	} else if (strncmp(op, "du", 2) == 0) {
 		ushort regs[6];
 		int ok = 1;
@@ -417,6 +439,7 @@
 	last_reg_lo  = reglo;
 	last_reg_hi  = reghi;
 	last_data    = data;
+	last_mask    = mask;
 
 	return rcode;
 }
@@ -424,13 +447,15 @@
 /***************************************************/
 
 U_BOOT_CMD(
-	mii,	5,	1,	do_mii,
+	mii, 6, 1, do_mii,
 	"MII utility commands",
-	"device                     - list available devices\n"
-	"mii device <devname>           - set current device\n"
-	"mii info   <addr>              - display MII PHY info\n"
-	"mii read   <addr> <reg>        - read  MII PHY <addr> register <reg>\n"
-	"mii write  <addr> <reg> <data> - write MII PHY <addr> register <reg>\n"
-	"mii dump   <addr> <reg>        - pretty-print <addr> <reg> (0-5 only)\n"
+	"device                             - list available devices\n"
+	"mii device <devname>                  - set current device\n"
+	"mii info   <addr>                     - display MII PHY info\n"
+	"mii read   <addr> <reg>               - read  MII PHY <addr> register <reg>\n"
+	"mii write  <addr> <reg> <data>        - write MII PHY <addr> register <reg>\n"
+	"mii modify <addr> <reg> <data> <mask> - modify MII PHY <addr> register <reg>\n"
+	"                                        updating bits identified in <mask>\n"
+	"mii dump   <addr> <reg>               - pretty-print <addr> <reg> (0-5 only)\n"
 	"Addr and/or reg may be ranges, e.g. 2-7."
 );

-- 
Scanned by iCritical.