mmc: Add 'mmc rst-function' sub-command

Some eMMC chips may need the RST_n_FUNCTION bit set to a non-zero value in order for warm reset of the system to work. Details on this being required will be part of the eMMC datasheet. Also add using this command to the dra7xx README. * Whitespace fix by panto Signed-off-by: Tom Rini <trini@ti.com> Acked-by: Pantelis Antoniou <panto@antoniou-consulting.com>

mmc: Add 'mmc rst-function' sub-command
Some eMMC chips may need the RST_n_FUNCTION bit set to a non-zero value in order for warm reset of the system to work. Details on this being required will be part of the eMMC datasheet. Also add using this command to the dra7xx README. * Whitespace fix by panto Signed-off-by: Tom Rini <trini@ti.com> Acked-by: Pantelis Antoniou <panto@antoniou-consulting.com>
Tom Rini · Pantelis Antoniou
1 parent 74c32ef58d
Showing 4 changed files with 53 additions and 0 deletions Side-by-side Diff
board/ti/dra7xx/README
common/cmd_mmc.c
drivers/mmc/mmc.c
include/mmc.h
@@ -23,4 +23,5 @@
 U-Boot # mmc write ${loadaddr} 300 400
 U-Boot # mmc bootbus 1 2 0 2
 U-Boot # mmc partconf 1 1 1 0
+U-Boot # mmc rst-function 1 1
@@ -330,6 +330,40 @@
 			printf("EMMC boot partition Size change Failed.\n");
 			return 1;
 		}
+	} else if (strcmp(argv[1], "rst-function") == 0) {
+		/*
+		 * Set the RST_n_ENABLE bit of RST_n_FUNCTION
+		 * The only valid values are 0x0, 0x1 and 0x2 and writing
+		 * a value of 0x1 or 0x2 sets the value permanently.
+		 */
+		int dev;
+		struct mmc *mmc;
+		u8 enable;
+
+		if (argc == 4) {
+			dev = simple_strtoul(argv[2], NULL, 10);
+			enable = simple_strtoul(argv[3], NULL, 10);
+		} else {
+			return CMD_RET_USAGE;
+		}
+
+		if (enable > 2 || enable < 0) {
+			puts("Invalid RST_n_ENABLE value\n");
+			return CMD_RET_USAGE;
+		}
+
+		mmc = find_mmc_device(dev);
+		if (!mmc) {
+			printf("no mmc device at slot %x\n", dev);
+			return 1;
+		}
+
+		if (IS_SD(mmc)) {
+			puts("RST_n_FUNCTION only exists on eMMC\n");
+			return 1;
+		}
+
+		return mmc_set_rst_n_function(mmc, enable);
 #endif /* CONFIG_SUPPORT_EMMC_BOOT */
 	}
  
@@ -436,6 +470,9 @@
 	" - Change sizes of boot and RPMB partitions of specified device\n"
 	"mmc partconf dev boot_ack boot_partition partition_access\n"
 	" - Change the bits of the PARTITION_CONFIG field of the specified device\n"
+	"mmc rst-function dev value\n"
+	" - Change the RST_n_FUNCTION field of the specified device\n"
+	"   WARNING: This is a write-once field and 0 / 1 / 2 are the only valid values.\n"
 #endif
 	"mmc setdsr - set DSR register value\n"
 	);
@@ -1513,5 +1513,17 @@
 		return err;
 	return 0;
 }
+
+/*
+ * Modify EXT_CSD[162] which is RST_n_FUNCTION based on the given value
+ * for enable.  Note that this is a write-once field for non-zero values.
+ *
+ * Returns 0 on success.
+ */
+int mmc_set_rst_n_function(struct mmc *mmc, u8 enable)
+{
+	return mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_RST_N_FUNCTION,
+			  enable);
+}
 #endif
@@ -150,6 +150,7 @@
 #define EXT_CSD_GP_SIZE_MULT		143	/* R/W */
 #define EXT_CSD_PARTITIONS_ATTRIBUTE	156	/* R/W */
 #define EXT_CSD_PARTITIONING_SUPPORT	160	/* RO */
+#define EXT_CSD_RST_N_FUNCTION		162	/* R/W */
 #define EXT_CSD_RPMB_MULT		168	/* RO */
 #define EXT_CSD_ERASE_GROUP_DEF		175	/* R/W */
 #define EXT_CSD_BOOT_BUS_WIDTH		177
@@ -332,6 +333,8 @@
 int mmc_set_part_conf(struct mmc *mmc, u8 ack, u8 part_num, u8 access);
 /* Function to modify the BOOT_BUS_WIDTH field of EXT_CSD */
 int mmc_set_boot_bus_width(struct mmc *mmc, u8 width, u8 reset, u8 mode);
+/* Function to modify the RST_n_FUNCTION field of EXT_CSD */
+int mmc_set_rst_n_function(struct mmc *mmc, u8 enable);
  
 /**
  * Start device initialization and return immediately; it does not block on
...	...	@@ -23,4 +23,5 @@
23	23	U-Boot # mmc write ${loadaddr} 300 400
24	24	U-Boot # mmc bootbus 1 2 0 2
25	25	U-Boot # mmc partconf 1 1 1 0
	26	+U-Boot # mmc rst-function 1 1
...	...	@@ -330,6 +330,40 @@
330	330	printf("EMMC boot partition Size change Failed.\n");
331	331	return 1;
332	332	}
	333	+ } else if (strcmp(argv[1], "rst-function") == 0) {
	334	+ /*
	335	+ * Set the RST_n_ENABLE bit of RST_n_FUNCTION
	336	+ * The only valid values are 0x0, 0x1 and 0x2 and writing
	337	+ * a value of 0x1 or 0x2 sets the value permanently.
	338	+ */
	339	+ int dev;
	340	+ struct mmc *mmc;
	341	+ u8 enable;
	342	+
	343	+ if (argc == 4) {
	344	+ dev = simple_strtoul(argv[2], NULL, 10);
	345	+ enable = simple_strtoul(argv[3], NULL, 10);
	346	+ } else {
	347	+ return CMD_RET_USAGE;
	348	+ }
	349	+
	350	+ if (enable > 2 \|\| enable < 0) {
	351	+ puts("Invalid RST_n_ENABLE value\n");
	352	+ return CMD_RET_USAGE;
	353	+ }
	354	+
	355	+ mmc = find_mmc_device(dev);
	356	+ if (!mmc) {
	357	+ printf("no mmc device at slot %x\n", dev);
	358	+ return 1;
	359	+ }
	360	+
	361	+ if (IS_SD(mmc)) {
	362	+ puts("RST_n_FUNCTION only exists on eMMC\n");
	363	+ return 1;
	364	+ }
	365	+
	366	+ return mmc_set_rst_n_function(mmc, enable);
333	367	#endif /* CONFIG_SUPPORT_EMMC_BOOT */
334	368	}
335	369
...	...	@@ -436,6 +470,9 @@
436	470	" - Change sizes of boot and RPMB partitions of specified device\n"
437	471	"mmc partconf dev boot_ack boot_partition partition_access\n"
438	472	" - Change the bits of the PARTITION_CONFIG field of the specified device\n"
	473	+ "mmc rst-function dev value\n"
	474	+ " - Change the RST_n_FUNCTION field of the specified device\n"
	475	+ " WARNING: This is a write-once field and 0 / 1 / 2 are the only valid values.\n"
439	476	#endif
440	477	"mmc setdsr - set DSR register value\n"
441	478	);
...	...	@@ -1513,5 +1513,17 @@
1513	1513	return err;
1514	1514	return 0;
1515	1515	}
	1516	+
	1517	+/*
	1518	+ * Modify EXT_CSD[162] which is RST_n_FUNCTION based on the given value
	1519	+ * for enable. Note that this is a write-once field for non-zero values.
	1520	+ *
	1521	+ * Returns 0 on success.
	1522	+ */
	1523	+int mmc_set_rst_n_function(struct mmc *mmc, u8 enable)
	1524	+{
	1525	+ return mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_RST_N_FUNCTION,
	1526	+ enable);
	1527	+}
1516	1528	#endif
...	...	@@ -150,6 +150,7 @@
150	150	#define EXT_CSD_GP_SIZE_MULT 143 /* R/W */
151	151	#define EXT_CSD_PARTITIONS_ATTRIBUTE 156 /* R/W */
152	152	#define EXT_CSD_PARTITIONING_SUPPORT 160 /* RO */
	153	+#define EXT_CSD_RST_N_FUNCTION 162 /* R/W */
153	154	#define EXT_CSD_RPMB_MULT 168 /* RO */
154	155	#define EXT_CSD_ERASE_GROUP_DEF 175 /* R/W */
155	156	#define EXT_CSD_BOOT_BUS_WIDTH 177
...	...	@@ -332,6 +333,8 @@
332	333	int mmc_set_part_conf(struct mmc *mmc, u8 ack, u8 part_num, u8 access);
333	334	/* Function to modify the BOOT_BUS_WIDTH field of EXT_CSD */
334	335	int mmc_set_boot_bus_width(struct mmc *mmc, u8 width, u8 reset, u8 mode);
	336	+/* Function to modify the RST_n_FUNCTION field of EXT_CSD */
	337	+int mmc_set_rst_n_function(struct mmc *mmc, u8 enable);
335	338
336	339	/**
337	340	* Start device initialization and return immediately; it does not block on