ARM: omap-common: Add board detection support for TI EVMs

Early clock initialization is currently done in two stages for OMAP4/5 SoCs. The first stage is the initialization of console clocks and then we initialize basic clocks for functionality necessary for SoC initialization and basic board functionality.

By splitting up prcm_init and centralizing this clock initialization, we setup the code for follow on patches that can do board specific initialization such as board detection which will depend on these basic clocks.

As part of this change, since the early clock initialization is centralized, we no longer need to expose the console clock initialization.

NOTE: we change the sequence slightly by initializing console clocks timer after the io settings are complete, but this is not expected to have any functioanlity impact since we setup the basic IO drive strength initialization as part of do_io_settings

Signed-off-by Steve Kipisz <[email protected]>

Reviewed-by Tom Rini <[email protected]<

---
v3 Based on:
master 83bf0057 arm: at91: reworked meesc board support

Changes in v3 (since v2):
- Remove SPL-only build of setup_clocks_for_console since it needs to be built in u-boot for NOR boot
- Move setup_clocks_for_console from top of setup_early_clocks to inside the switch statement.

v2: http://marc.info/?t=144655363000001&r=1&w=2
(mailing list squashed original submission)

Changes in v2:
- New patch

 arch/arm/cpu/armv7/omap-common/clocks-common.c | 21 +++++++++++++++++++--
 arch/arm/cpu/armv7/omap-common/hwinit-common.c |  3 +--
 arch/arm/include/asm/arch-omap4/sys_proto.h    |  2 +-
 arch/arm/include/asm/arch-omap5/sys_proto.h    |  2 +-
 4 files changed, 22 insertions(+), 6 deletions(-)

arch/arm/cpu/armv7/omap-common/clocks-common.c +19 -2

index e28b79568d1d..367d224361be 100644
@@ -769,7 +769,7 @@ void lock_dpll(u32 const base)
 	wait_for_lock(base);
 }
 
-void setup_clocks_for_console(void)
+static void setup_clocks_for_console(void)
 {
 	/* Do not add any spl_debug prints in this function */
 	clrsetbits_le32((*prcm)->cm_l4per_clkstctrl, CD_CLKCTRL_CLKTRCTRL_MASK,

@@ -853,14 +853,31 @@ void do_disable_clocks(u32 const *clk_domains,
 		disable_clock_domain(clk_domains[i]);
 }
 
-void prcm_init(void)
+/**
+ * setup_early_clocks() - Setup early clocks needed for SoC
+ *
+ * Setup clocks for console, SPL basic initialization clocks and initialize
+ * the timer. This is invoked prior prcm_init.
+ */
+void setup_early_clocks(void)
 {
 	switch (omap_hw_init_context()) {
 	case OMAP_INIT_CONTEXT_SPL:
 	case OMAP_INIT_CONTEXT_UBOOT_FROM_NOR:
 	case OMAP_INIT_CONTEXT_UBOOT_AFTER_CH:
+		setup_clocks_for_console();
 		enable_basic_clocks();
 		timer_init();
+		/* Fall through */
+	}
+}
+
+void prcm_init(void)
+{
+	switch (omap_hw_init_context()) {
+	case OMAP_INIT_CONTEXT_SPL:
+	case OMAP_INIT_CONTEXT_UBOOT_FROM_NOR:
+	case OMAP_INIT_CONTEXT_UBOOT_AFTER_CH:
 		scale_vcores(*omap_vcores);
 		setup_dplls();
 		setup_warmreset_time();

arch/arm/cpu/armv7/omap-common/hwinit-common.c +1 -2

index 80794f9c611a..91f2dead364b 100644
@@ -125,10 +125,9 @@ void s_init(void)
 	set_mux_conf_regs();
 #ifdef CONFIG_SPL_BUILD
 	srcomp_enable();
-	setup_clocks_for_console();
-
 	do_io_settings();
 #endif
+	setup_early_clocks();
 	prcm_init();
 }
 

arch/arm/include/asm/arch-omap4/sys_proto.h +1 -1

index f30f86539130..71e3d776aa0d 100644
@@ -37,7 +37,7 @@ void do_set_mux(u32 base, struct pad_conf_entry const *array, int size);
 void set_muxconf_regs_essential(void);
 u32 wait_on_value(u32, u32, void *, u32);
 void sdelay(unsigned long);
-void setup_clocks_for_console(void);
+void setup_early_clocks(void);
 void prcm_init(void);
 void bypass_dpll(u32 const base);
 void freq_update_core(void);

arch/arm/include/asm/arch-omap5/sys_proto.h +1 -1

index 7fcb78389403..b9e09e7c52a8 100644
@@ -48,7 +48,7 @@ void do_set_mux32(u32 base, struct pad_conf_entry const *array, int size);
 void set_muxconf_regs_essential(void);
 u32 wait_on_value(u32, u32, void *, u32);
 void sdelay(unsigned long);
-void setup_clocks_for_console(void);
+void setup_early_clocks(void);
 void prcm_init(void);
 void bypass_dpll(u32 const base);
 void freq_update_core(void);

Centralize gpi2c_init into omap_common from the sys_proto header so that the information can be reused across SoCs.

Signed-off-by Steve Kipisz <[email protected]>

Reviewed-by Tom Rini <[email protected]>

---
v3 Based on:
master 83bf0057 arm: at91: reworked meesc board support

Changes in v3 (since v2):
- No changes

v2: http://marc.info/?t=144655344600007&r=1&w=2
(mailing list squashed original submission)

Changes in v2:
- New Patch

 arch/arm/include/asm/arch-omap4/sys_proto.h | 1 -
 arch/arm/include/asm/arch-omap5/sys_proto.h | 1 -
 arch/arm/include/asm/omap_common.h          | 3 +++
 3 files changed, 3 insertions(+), 2 deletions(-)

arch/arm/include/asm/arch-omap4/sys_proto.h +0 -1

index 71e3d776aa0d..26e9a194f036 100644
@@ -51,7 +51,6 @@ void save_omap_boot_params(void);
 void init_omap_revision(void);
 void do_io_settings(void);
 void sri2c_init(void);
-void gpi2c_init(void);
 int omap_vc_bypass_send_value(u8 sa, u8 reg_addr, u8 reg_data);
 u32 warm_reset(void);
 void force_emif_self_refresh(void);

arch/arm/include/asm/arch-omap5/sys_proto.h +0 -1

index b9e09e7c52a8..18902628739b 100644
@@ -62,7 +62,6 @@ void save_omap_boot_params(void);
 void init_omap_revision(void);
 void do_io_settings(void);
 void sri2c_init(void);
-void gpi2c_init(void);
 int omap_vc_bypass_send_value(u8 sa, u8 reg_addr, u8 reg_data);
 u32 warm_reset(void);
 void force_emif_self_refresh(void);

arch/arm/include/asm/omap_common.h +3 -0

index d7b81c101b79..d773b0430ad4 100644
@@ -617,6 +617,9 @@ void disable_edma3_clocks(void);
 
 void omap_die_id(unsigned int *die_id);
 
+/* Initialize general purpose I2C(0) on the SoC */
+void gpi2c_init(void);
+
 /* ABB */
 #define OMAP_ABB_NOMINAL_OPP		0
 #define OMAP_ABB_FAST_OPP		1

From: Lokesh Vutla <[email protected]>

Several TI EVMs have EEPROM that can contain board description information such as revision, DDR definition, serial number, etc. In just about all cases, these EEPROM are on the I2C bus and provides us the opportunity to centralize the generic operations involved.

The on-board EEPROM on the BeagleBone Black, BeagleBone, AM335x EVM, AM43x GP EVM, AM57xx-evm, BeagleBoard-X15 share the same format. However, DRA-7* EVMs, OMAP4SDP use a modified format.

We hence introduce logic which is generic between these platforms without enforcing any specific format. This allows the boards to use the relevant format for operations that they might choose.

This module will compile for all TI SoC based boards when I2C is enabled, even non-TI boards that do not have the EEPROM. If the functions are not used, they will not be linked in.

It is important to note that this logic is fundamental to the board configuration process such as DDR configuration which is needed in SPL, hence cannot be part of the standard u-boot driver model (which is available later in the process). Hence, to aid efficiency, the eeprom contents are copied over to SRAM scratchpad memory area at the first invocation to retrieve data.

The follow on patches introduce the use of this library for AM57x platform support. AM335x/AM43xx cleanups need to first ensure usage of omap_common prior to switch over to this generic solution.

Signed-off-by Lokesh Vutla <[email protected]>

Signed-off-by Steve Kipisz <[email protected]>

---
v3 Based on:
master 83bf0057 arm: at91: reworked meesc board support

Changes in v3 (since v2):
- Create a new directory board/ti/common for code common to TI board
- Move the EEPROM code to the new directory
- Move the inline code that access the EEPROM data from omap_common.h to new files in the common directory

v2: http://marc.info/?t=144655344800001&r=1&w=2
(mailing list squashed original submission)

Changes in v2:
- New Patch

 arch/arm/include/asm/omap_common.h |   5 +-
 board/ti/am57xx/Makefile           |   2 +
 board/ti/common/board.c            |  54 ++++++++++++++
 board/ti/common/board.h            | 117 +++++++++++++++++++++++++++++
 board/ti/common/ti-i2c-eeprom.c    | 148 +++++++++++++++++++++++++++++++++++++
 5 files changed, 325 insertions(+), 1 deletion(-)
 create mode 100644 board/ti/common/board.c
 create mode 100644 board/ti/common/board.h
 create mode 100644 board/ti/common/ti-i2c-eeprom.c

arch/arm/include/asm/omap_common.h +3 -1

index d773b0430ad4..f6d929b15e82 100644
@@ -713,7 +713,9 @@ static inline u8 is_dra72x(void)
 #define OMAP_SRAM_SCRATCH_VCORES_PTR    (SRAM_SCRATCH_SPACE_ADDR + 0x1C)
 #define OMAP_SRAM_SCRATCH_SYS_CTRL	(SRAM_SCRATCH_SPACE_ADDR + 0x20)
 #define OMAP_SRAM_SCRATCH_BOOT_PARAMS	(SRAM_SCRATCH_SPACE_ADDR + 0x24)
-#define OMAP5_SRAM_SCRATCH_SPACE_END	(SRAM_SCRATCH_SPACE_ADDR + 0x28)
+#define OMAP_SRAM_SCRATCH_BOARD_EEPROM_START (SRAM_SCRATCH_SPACE_ADDR + 0x28)
+#define OMAP_SRAM_SCRATCH_BOARD_EEPROM_END (SRAM_SCRATCH_SPACE_ADDR + 0x200)
+#define OMAP_SRAM_SCRATCH_SPACE_END	(OMAP_SRAM_SCRATCH_BOARD_EEPROM_END)
 
 /* Boot parameters */
 #define DEVICE_DATA_OFFSET	0x18

arch/arm/include/asm/omap_common.h +0 -0

 #endif /* _OMAP_COMMON_H_ */

board/ti/am57xx/Makefile +2 -0

index 5cd6873f5e97..9d85d31b2cf1 100644
@@ -6,3 +6,5 @@
 #
 
 obj-y	:= board.o
+obj-y	+= ../common/board.o
 
+obj-${CONFIG_I2C} += ../common/ti-i2c-eeprom.o

board/ti/common/board.c new file +0 -0

new file mode 100644
index 000000000000..1c02e44916f0

board/ti/common/board.c new file +7 -0

+ *
+ * Copyright (C) 2015, Texas Instruments Incorporated - http://www.ti.com
+ *
+ * Author: Steven Kipisz <[email protected]>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */

board/ti/common/board.c new file +4 -0

+{
+	struct ti_am_eeprom *ep = TI_AM_EEPROM_DATA;
+
+	if (ep->header != TI_EEPROM_HEADER_MAGIC)

board/ti/common/board.c new file +10 -0

+{
+	struct ti_am_eeprom *ep = TI_AM_EEPROM_DATA;
+	int l;
+
+	if (ep->header != TI_EEPROM_HEADER_MAGIC)
+		return false;
+
+	l = cmp_len > TI_EEPROM_HDR_REV_LEN ? TI_EEPROM_HDR_NAME_LEN : cmp_len;
+	return !strncmp(ep->version, rev_tag, l);
+}

board/ti/common/board.h new file +0 -0

new file mode 100644
index 000000000000..19d63cad82f9

board/ti/common/board.h new file +96 -0

+
+/* TI EEPROM MAGIC Header identifier */
+#define TI_EEPROM_HEADER_MAGIC	0xEE3355AA
+
+#define TI_EEPROM_HDR_NAME_LEN		8
+#define TI_EEPROM_HDR_REV_LEN		12
+#define TI_EEPROM_HDR_SERIAL_LEN	4
+#define TI_EEPROM_HDR_CONFIG_LEN	32
+#define TI_EEPROM_HDR_NO_OF_MAC_ADDR	3
+#define TI_EEPROM_HDR_ETH_ALEN		6
+
+/**
+ * struct ti_am_eeprom - This structure holds data read in from the
+ *                     AM335x, AM437x, AM57xx TI EVM EEPROMs.
+ * @header: This holds the magic number
+ * @name: The name of the board
+ * @version: Board revision
+ * @serial: Board serial number
+ * @config: Reserved
+ * @mac_addr: Any MAC addresses written in the EEPROM
+ *
+ * The data is this structure is read from the EEPROM on the board.
+ * It is used for board detection which is based on name. It is used
+ * to configure specific TI boards. This allows booting of multiple
+ * TI boards with a single MLO and u-boot.
+ */
+struct ti_am_eeprom {
+	unsigned int header;
+	char name[TI_EEPROM_HDR_NAME_LEN];
+	char version[TI_EEPROM_HDR_REV_LEN];
+	char serial[TI_EEPROM_HDR_SERIAL_LEN];
+	char config[TI_EEPROM_HDR_CONFIG_LEN];
+	char mac_addr[TI_EEPROM_HDR_NO_OF_MAC_ADDR][TI_EEPROM_HDR_ETH_ALEN];
+} __attribute__ ((__packed__));
+
+/**
+ * struct ti_am_eeprom_printable - Null terminated, printable EEPROM contents
+ * @name:	NULL terminated name
+ * @version:	NULL terminated version
+ * @serial:	NULL terminated serial number
+ */
+struct ti_am_eeprom_printable {
+	char name[TI_EEPROM_HDR_NAME_LEN + 1];
+	char version[TI_EEPROM_HDR_REV_LEN + 1];
+	char serial[TI_EEPROM_HDR_SERIAL_LEN + 1];
+};
+#define TI_AM_EEPROM_DATA ((struct ti_am_eeprom *)\
+				OMAP_SRAM_SCRATCH_BOARD_EEPROM_START)
+
+/**
+ * ti_i2c_eeprom_am_get() - Consolidated eeprom data collection for AM* TI EVMs
+ * @bus_addr:	I2C bus address
+ * @dev_addr:	I2C slave address
+ * @ep:		Pointer to eeprom structure
+ *
+ * *ep is populated by the this AM generic function that consolidates
+ * the basic initialization logic common accross all AM* platforms.
+ */
+int ti_i2c_eeprom_am_get(int bus_addr, int dev_addr, struct ti_am_eeprom **epp);
+
+/**
+ * ti_i2c_eeprom_am_get_print() - Get a printable representation of eeprom data
+ * @bus_addr:	I2C bus address
+ * @dev_addr:	I2C slave address
+ * @p:		Pointer to eeprom structure
+ *
+ * This reads the eeprom and converts the data into a printable string for
+ * further processing.
+ */
+int ti_i2c_eeprom_am_get_print(int bus_addr, int dev_addr,
+			       struct ti_am_eeprom_printable *p);
+
+/**
+ * set_board_info_env() - Setup commonly used board information environment vars
+ * @name:	Name of the board
+ * @revision:	Revision of the board
+ * @serial:	Serial Number of the board
+ *
+ * In case of NULL revision or serial information "unknown" is setup.
+ * If name is NULL, default_name is used.
+ */
+void set_board_info_env(char *name, char *revision,
+			char *serial);
+
+/**
+ * board_am_is() - Generic Board detection logic
+ * @name_tag:	Tag used in eeprom for the board
+ *
+ * Return: false if board information does not match OR eeprom was'nt read.
+ *	   true otherwise
+ */
+bool board_am_is(char *name_tag);
+
+/**
+ * board_am_rev_is() - Compare board revision
+ * @rev_tag:	Revision tag to check in eeprom

board/ti/common/ti-i2c-eeprom.c new file +138 -0

new file mode 100644
index 000000000000..5ec499b51a5d
@@ -0,0 +1,148 @@
+/*
+ * Library to support early TI EVM EEPROM handling
+ *
+ * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
+ *	Lokesh Vutla
+ *	Steve Kipisz
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/omap_common.h>
+#include <i2c.h>
+
+#include "board.h"
+
+/**
+ * ti_i2c_eeprom_init - Initialize an i2c bus and probe for a device
+ * @i2c_bus: i2c bus number to initialize
+ * @dev_addr: Device address to probe for
+ *
+ * Return: 0 on success or corresponding error on failure.
+ */
+int __maybe_unused ti_i2c_eeprom_init(int i2c_bus, int dev_addr)
+{
+	int rc;
+
+	rc = i2c_set_bus_num(i2c_bus);
+	if (rc)
+		return rc;
+
+	return i2c_probe(dev_addr);
+}
+
+/**
+ * ti_i2c_eeprom_read - Read data from an EEPROM
+ * @dev_addr: The device address of the EEPROM
+ * @offset: Offset to start reading in the EEPROM
+ * @ep: Pointer to a buffer to read into
+ * @epsize: Size of buffer
+ *
+ * Return: 0 on success or corresponding result of i2c_read
+ */
+int __maybe_unused ti_i2c_eeprom_read(int dev_addr, int offset, uchar *ep,
+				     int epsize)
+{
+	return i2c_read(dev_addr, offset, 2, ep, epsize);
+}
+
+/**
+ * ti_eeprom_string_cleanup() - Handle eeprom programming errors
+ * @s:	eeprom string (should be NULL terminated)
+ *
+ * Some Board manufacturers do not add a NULL termination at the
+ * end of string, instead some binary information is kludged in, hence
+ * convert the string to just printable characters of ASCII chart.
+ */
+void __maybe_unused ti_eeprom_string_cleanup(char *s)
+{
+	int i, l;
+
+	l = strlen(s);
+	for (i = 0; i < l; i++, s++)
+		if (*s < ' ' || *s > '~') {
+			*s = 0;
+			break;
+		}
+}
+
+int __maybe_unused ti_i2c_eeprom_am_get(int bus_addr, int dev_addr,
+					struct ti_am_eeprom **epp)
+{
+	int rc;
+	struct ti_am_eeprom *ep;
+
+	if (!epp)
+		return -1;
+
+	ep = TI_AM_EEPROM_DATA;
+	if (ep->header == TI_EEPROM_HEADER_MAGIC)
+		goto already_read;
+
+	/* Initialize with a known bad marker for i2c fails.. */
+	ep->header = 0xADEAD12C;
+
+	gpi2c_init();
+	rc = ti_i2c_eeprom_init(bus_addr, dev_addr);
+	if (rc)
+		return rc;
+	rc = i2c_read(dev_addr, 0x0, 2, (uint8_t *)ep, sizeof(*ep));
+	if (rc)
+		return rc;
+
+	/* Corrupted data??? */
+	if (ep->header != TI_EEPROM_HEADER_MAGIC)
+		return -1;
+
+already_read:
+	*epp = ep;
+
+	return 0;
+}
+
+int __maybe_unused ti_i2c_eeprom_am_get_print(int bus_addr, int dev_addr,
+					      struct ti_am_eeprom_printable *p)
+{
+	struct ti_am_eeprom *ep;
+	int rc;
+
+	/* Incase of invalid eeprom contents */
+	p->name[0] = 0x00;
+	p->version[0] = 0x00;
+	p->serial[0] = 0x00;
+
+	rc = ti_i2c_eeprom_am_get(bus_addr, dev_addr, &ep);
+	if (rc)
+		return rc;
+
+	/*
+	 * Alas! we have to null terminate and cleanup the strings!
+	 */
+	strlcpy(p->name, ep->name, TI_EEPROM_HDR_NAME_LEN);
+	ti_eeprom_string_cleanup(p->name);
+	strlcpy(p->version, ep->version, TI_EEPROM_HDR_NAME_LEN);
+	ti_eeprom_string_cleanup(p->version);
+	strlcpy(p->serial, ep->serial, TI_EEPROM_HDR_NAME_LEN);
+	ti_eeprom_string_cleanup(p->serial);
+	return 0;
+}
+
+void __maybe_unused set_board_info_env(char *name, char *revision,
+				       char *serial)
+{
+	char *unknown = "unknown";
+
+	if (name)
+		setenv("board_name", name);
+

board/ti/am57xx/Makefile line 9

Quoted 8 lines

index 5cd6873f5e97..9d85d31b2cf1 100644

board/ti/am57xx/Makefile +1 -0

@@ -6,3 +6,5 @@
 #
 
 obj-y	:= board.o
+obj-y	+= ../common/board.o

board/ti/common/board.h new file +117 -0

@@ -0,0 +1,117 @@
+/*
+ * board.h
+ * TI AMxxxx common board information header
+ *
+ * Copyright (C) 2015, Texas Instruments, Incorporated - http://www.ti.com
+ *
+ * SPDX-L	icense-Identifier:	GPL-2.0+
+ */
+
+/* Common I2C eeprom definitions */
+#ifndef __ASSEMBLY__
+
+/* TI EEPROM MAGIC Header identifier */
+#define TI_EEPROM_HEADER_MAGIC	0xEE3355AA
+
+#define TI_EEPROM_HDR_NAME_LEN		8
+#define TI_EEPROM_HDR_REV_LEN		12
+#define TI_EEPROM_HDR_SERIAL_LEN	4
+#define TI_EEPROM_HDR_CONFIG_LEN	32
+#define TI_EEPROM_HDR_NO_OF_MAC_ADDR	3
+#define TI_EEPROM_HDR_ETH_ALEN		6
+
+/**
+ * struct ti_am_eeprom - This structure holds data read in from the
+ *                     AM335x, AM437x, AM57xx TI EVM EEPROMs.
+ * @header: This holds the magic number
+ * @name: The name of the board
+ * @version: Board revision
+ * @serial: Board serial number
+ * @config: Reserved
+ * @mac_addr: Any MAC addresses written in the EEPROM
+ *
+ * The data is this structure is read from the EEPROM on the board.
+ * It is used for board detection which is based on name. It is used
+ * to configure specific TI boards. This allows booting of multiple
+ * TI boards with a single MLO and u-boot.
+ */
+struct ti_am_eeprom {
+	unsigned int header;
+	char name[TI_EEPROM_HDR_NAME_LEN];
+	char version[TI_EEPROM_HDR_REV_LEN];
+	char serial[TI_EEPROM_HDR_SERIAL_LEN];
+	char config[TI_EEPROM_HDR_CONFIG_LEN];
+	char mac_addr[TI_EEPROM_HDR_NO_OF_MAC_ADDR][TI_EEPROM_HDR_ETH_ALEN];
+} __attribute__ ((__packed__));
+
+/**
+ * struct ti_am_eeprom_printable - Null terminated, printable EEPROM contents
+ * @name:	NULL terminated name
+ * @version:	NULL terminated version
+ * @serial:	NULL terminated serial number
+ */
+struct ti_am_eeprom_printable {
+	char name[TI_EEPROM_HDR_NAME_LEN + 1];
+	char version[TI_EEPROM_HDR_REV_LEN + 1];
+	char serial[TI_EEPROM_HDR_SERIAL_LEN + 1];
+};
+#define TI_AM_EEPROM_DATA ((struct ti_am_eeprom *)\
+				OMAP_SRAM_SCRATCH_BOARD_EEPROM_START)
+
+/**
+ * ti_i2c_eeprom_am_get() - Consolidated eeprom data collection for AM* TI EVMs
+ * @bus_addr:	I2C bus address
+ * @dev_addr:	I2C slave address
+ * @ep:		Pointer to eeprom structure
+ *
+ * *ep is populated by the this AM generic function that consolidates
+ * the basic initialization logic common accross all AM* platforms.
+ */
+int ti_i2c_eeprom_am_get(int bus_addr, int dev_addr, struct ti_am_eeprom **epp);
+
+/**
+ * ti_i2c_eeprom_am_get_print() - Get a printable representation of eeprom data
+ * @bus_addr:	I2C bus address
+ * @dev_addr:	I2C slave address
+ * @p:		Pointer to eeprom structure
+ *
+ * This reads the eeprom and converts the data into a printable string for
+ * further processing.
+ */
+int ti_i2c_eeprom_am_get_print(int bus_addr, int dev_addr,
+			       struct ti_am_eeprom_printable *p);
+
+/**
+ * set_board_info_env() - Setup commonly used board information environment vars
+ * @name:	Name of the board
+ * @revision:	Revision of the board
+ * @serial:	Serial Number of the board
+ *
+ * In case of NULL revision or serial information "unknown" is setup.
+ * If name is NULL, default_name is used.
+ */
+void set_board_info_env(char *name, char *revision,
+			char *serial);
+
+/**
+ * board_am_is() - Generic Board detection logic
+ * @name_tag:	Tag used in eeprom for the board
+ *
+ * Return: false if board information does not match OR eeprom was'nt read.
+ *	   true otherwise
+ */
+bool board_am_is(char *name_tag);
+
+/**
+ * board_am_rev_is() - Compare board revision
+ * @rev_tag:	Revision tag to check in eeprom
+ * @cmp_len:	How many chars to compare?
+ *
+ * NOTE: revision information is often messed up (hence the str len match) :(
+ *
+ * Return: false if board information does not match OR eeprom was'nt read.
+ *	   true otherwise
+ */
+bool board_am_rev_is(char *rev_tag, int cmp_len);
+
+#endif	/* __ASSEMBLY__ */

board/ti/common/ti-i2c-eeprom.c new file +148 -0

new file mode 100644
index 000000000000..5ec499b51a5d
@@ -0,0 +1,148 @@
+/*
+ * Library to support early TI EVM EEPROM handling
+ *
+ * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
+ *	Lokesh Vutla
+ *	Steve Kipisz
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/omap_common.h>
+#include <i2c.h>
+
+#include "board.h"
+
+/**
+ * ti_i2c_eeprom_init - Initialize an i2c bus and probe for a device
+ * @i2c_bus: i2c bus number to initialize
+ * @dev_addr: Device address to probe for
+ *
+ * Return: 0 on success or corresponding error on failure.
+ */
+int __maybe_unused ti_i2c_eeprom_init(int i2c_bus, int dev_addr)
+{
+	int rc;
+
+	rc = i2c_set_bus_num(i2c_bus);
+	if (rc)
+		return rc;
+
+	return i2c_probe(dev_addr);
+}
+
+/**
+ * ti_i2c_eeprom_read - Read data from an EEPROM
+ * @dev_addr: The device address of the EEPROM
+ * @offset: Offset to start reading in the EEPROM
+ * @ep: Pointer to a buffer to read into
+ * @epsize: Size of buffer
+ *
+ * Return: 0 on success or corresponding result of i2c_read
+ */
+int __maybe_unused ti_i2c_eeprom_read(int dev_addr, int offset, uchar *ep,
+				     int epsize)
+{
+	return i2c_read(dev_addr, offset, 2, ep, epsize);
+}
+
+/**
+ * ti_eeprom_string_cleanup() - Handle eeprom programming errors
+ * @s:	eeprom string (should be NULL terminated)
+ *
+ * Some Board manufacturers do not add a NULL termination at the
+ * end of string, instead some binary information is kludged in, hence
+ * convert the string to just printable characters of ASCII chart.
+ */
+void __maybe_unused ti_eeprom_string_cleanup(char *s)
+{
+	int i, l;
+
+	l = strlen(s);
+	for (i = 0; i < l; i++, s++)
+		if (*s < ' ' || *s > '~') {
+			*s = 0;
+			break;
+		}
+}
+
+int __maybe_unused ti_i2c_eeprom_am_get(int bus_addr, int dev_addr,
+					struct ti_am_eeprom **epp)
+{
+	int rc;
+	struct ti_am_eeprom *ep;
+
+	if (!epp)
+		return -1;
+
+	ep = TI_AM_EEPROM_DATA;
+	if (ep->header == TI_EEPROM_HEADER_MAGIC)
+		goto already_read;
+
+	/* Initialize with a known bad marker for i2c fails.. */
+	ep->header = 0xADEAD12C;
+
+	gpi2c_init();
+	rc = ti_i2c_eeprom_init(bus_addr, dev_addr);
+	if (rc)
+		return rc;
+	rc = i2c_read(dev_addr, 0x0, 2, (uint8_t *)ep, sizeof(*ep));
+	if (rc)
+		return rc;
+
+	/* Corrupted data??? */
+	if (ep->header != TI_EEPROM_HEADER_MAGIC)
+		return -1;
+
+already_read:
+	*epp = ep;
+
+	return 0;
+}
+
+int __maybe_unused ti_i2c_eeprom_am_get_print(int bus_addr, int dev_addr,
+					      struct ti_am_eeprom_printable *p)
+{
+	struct ti_am_eeprom *ep;
+	int rc;
+
+	/* Incase of invalid eeprom contents */
+	p->name[0] = 0x00;
+	p->version[0] = 0x00;
+	p->serial[0] = 0x00;
+
+	rc = ti_i2c_eeprom_am_get(bus_addr, dev_addr, &ep);
+	if (rc)
+		return rc;
+
+	/*
+	 * Alas! we have to null terminate and cleanup the strings!
+	 */
+	strlcpy(p->name, ep->name, TI_EEPROM_HDR_NAME_LEN);
+	ti_eeprom_string_cleanup(p->name);
+	strlcpy(p->version, ep->version, TI_EEPROM_HDR_NAME_LEN);
+	ti_eeprom_string_cleanup(p->version);
+	strlcpy(p->serial, ep->serial, TI_EEPROM_HDR_NAME_LEN);
+	ti_eeprom_string_cleanup(p->serial);
+	return 0;
+}
+
+void __maybe_unused set_board_info_env(char *name, char *revision,
+				       char *serial)
+{
+	char *unknown = "unknown";
+
+	if (name)
+		setenv("board_name", name);
+
+	if (revision)
+		setenv("board_revision", revision);
+	else
+		setenv("board_revision", unknown);
+
+	if (serial)
+		setenv("board_serial", serial);
+	else
+		setenv("board_serial", unknown);
+}

board/ti/common/board.h

Quoted 5 lines

board/ti/common/board.h new file +0 -0

new file mode 100644
index 000000000000..19d63cad82f9

May be keep this header file under arch/arm/include/asm/ so that it can be included properly.

Many TI EVMs have capability to store relevant board information such as DDR description in EEPROM. Further many pad configuration variations can occur as part of revision changes in the platform. In-order to support these at runtime, we for a board detection hook which is available for override from board files that may desire to do so.

NOTE: All TI EVMs are capable of detecting board information based on early clocks that are configured. However, in case of additional needs this can be achieved within the override logic from within the board file.

Signed-off-by Steve Kipisz <[email protected]>

Reviewed-by Tom Rini <[email protected]>

---
v3 Based on:
master 83bf0057 arm: at91: reworked meesc board support

Changes in v3 (since v2):
- No changes

v2: http://marc.info/?t=144655344600006&r=1&w=2
(mailing list squashed original submission)

Changes in v2:
- New patch

 arch/arm/cpu/armv7/omap-common/hwinit-common.c | 11 +++++++++++
 arch/arm/include/asm/arch-omap4/sys_proto.h    |  1 +
 arch/arm/include/asm/arch-omap5/sys_proto.h    |  1 +
 3 files changed, 13 insertions(+)

arch/arm/cpu/armv7/omap-common/hwinit-common.c +11 -0

index 91f2dead364b..9e9376d0e6e6 100644
@@ -97,6 +97,16 @@ int arch_cpu_init(void)
 }
 #endif /* CONFIG_ARCH_CPU_INIT */
 
+/**
+ * do_board_detect() - Detect board description
+ *
+ * Function to detect board description. This is expected to be
+ * overridden in the SoC family board file where desired.
+ */
+void __weak do_board_detect(void)
+{
+}
+
 /*
  * Routine: s_init
  * Description: Does early system init of watchdog, muxing,  andclocks

@@ -128,6 +138,7 @@ void s_init(void)
 	do_io_settings();
 #endif
 	setup_early_clocks();
+	do_board_detect();
 	prcm_init();
 }
 

arch/arm/include/asm/arch-omap4/sys_proto.h +1 -0

index 26e9a194f036..fbb52093c65a 100644
@@ -39,6 +39,7 @@ u32 wait_on_value(u32, u32, void *, u32);
 void sdelay(unsigned long);
 void setup_early_clocks(void);
 void prcm_init(void);
+void do_board_detect(void);
 void bypass_dpll(u32 const base);
 void freq_update_core(void);
 u32 get_sys_clk_freq(void);

arch/arm/include/asm/arch-omap5/sys_proto.h +1 -0

index 18902628739b..23a33cb233bb 100644
@@ -50,6 +50,7 @@ u32 wait_on_value(u32, u32, void *, u32);
 void sdelay(unsigned long);
 void setup_early_clocks(void);
 void prcm_init(void);
+void do_board_detect(void);
 void bypass_dpll(u32 const base);
 void freq_update_core(void);
 u32 get_sys_clk_freq(void);

Several TI EVMs have onboard EEPROM that contain board description information. The onboard EEPROM on Beaglebone, Beaglebone Black, AM335x EVM, AM43x EVM, AM57xx EVM, Beagleboard-x15 all share the same format.

This series of patches introduces code which is generic among these platforms. The boards can use the data for any operations they might choose.

Lokesh Vutla (1):
ARM: omap-common: Add standard access for board description EEPROM

Steve Kipisz (4):
ARM: OMAP4/5: Centralize early clock initialization
ARM: OMAP4/5: Centralize gpi2c_init
ARM: OMAP4/5: Add generic board detection hook
board: ti: AM57xx: Add detection logic for AM57xx-evm

 arch/arm/cpu/armv7/omap-common/clocks-common.c |  21 +++-
 arch/arm/cpu/armv7/omap-common/hwinit-common.c |  14 ++-
 arch/arm/include/asm/arch-omap4/sys_proto.h    |   4 +-
 arch/arm/include/asm/arch-omap5/sys_proto.h    |   4 +-
 arch/arm/include/asm/omap_common.h             |   8 +-
 board/ti/am57xx/Makefile                       |   2 +
 board/ti/am57xx/board.c                        |  52 +++++++++
 board/ti/common/board.c                        |  54 +++++++++
 board/ti/common/board.h                        | 117 +++++++++++++++++++
 board/ti/common/ti-i2c-eeprom.c                | 148 +++++++++++++++++++++++++
 include/configs/am57xx_evm.h                   |   4 +
 11 files changed, 419 insertions(+), 9 deletions(-)
 create mode 100644 board/ti/common/board.c
 create mode 100644 board/ti/common/board.h
 create mode 100644 board/ti/common/ti-i2c-eeprom.c