From bb99ad6d8257bf828f150d40f507b30d80a4a7ae Mon Sep 17 00:00:00 2001 From: Ben Warren Date: Thu, 7 Sep 2006 16:50:54 -0400 Subject: [PATCH] Add support for multiple I2C buses Hello, Attached is a patch providing support for multiple I2C buses at the command level. The second part of the patch includes an implementation for the MPC834x CPU and MPC8349EMDS board. /*** Note: This patch replaces ticket DNX#2006083042000018 ***/ Signed-off-by: Ben Warren Overview: 1. Include new 'i2c' command (based on USB implementation) using CONFIG_I2C_CMD_TREE. 2. Allow multiple buses by defining CONFIG_I2C_MULTI_BUS. Note that the commands to change bus number and speed are only available under the new 'i2c' command mentioned in the first bullet. 3. The option CFG_I2C_NOPROBES has been expanded to work in multi-bus systems. When CONFIG_I2C_MULTI_BUS is used, this option takes the form of an array of bus-device pairs. Otherwise, it is an array of uchar. CHANGELOG: Added new 'i2c' master command for all I2C interaction. This is conditionally compiled with CONFIG_I2C_CMD_TREE. New commands added for setting I2C bus speed as well as changing the active bus if the board has more than one (conditionally compiled with CONFIG_I2C_MULTI_BUS). Updated NOPROBE logic to handle multiple buses. Updated README. regards, Ben --- README | 42 ++++++++++++++- common/cmd_i2c.c | 159 +++++++++++++++++++++++++++++++++++++++++++++++++++++-- include/i2c.h | 45 ++++++++++++++++ 3 files changed, 240 insertions(+), 6 deletions(-) diff --git a/README b/README index b78ea61..6b94f84 100644 --- a/README +++ b/README @@ -1207,7 +1207,12 @@ The following options need to be configured: clock chips. See common/cmd_i2c.c for a description of the command line interface. - CONFIG_HARD_I2C selects the CPM hardware driver for I2C. + CONFIG_I2C_CMD_TREE is a recommended option that places + all I2C commands under a single 'i2c' root command. The + older 'imm', 'imd', 'iprobe' etc. commands are considered + deprecated and may disappear in the future. + + CONFIG_HARD_I2C selects a hardware I2C controller. CONFIG_SOFT_I2C configures u-boot to use a software (aka bit-banging) driver instead of CPM or similar hardware @@ -1312,6 +1317,31 @@ The following options need to be configured: in u-boot bd_info structure based on u-boot environment variable "i2cfast". (see also i2cfast) + CONFIG_I2C_MULTI_BUS + + This option allows the use of multiple I2C buses, each of which + must have a controller. At any point in time, only one bus is + active. To switch to a different bus, use the 'i2c dev' command. + Note that bus numbering is zero-based. + + CFG_I2C_NOPROBES + + This option specifies a list of I2C devices that will be skipped + when the 'i2c probe' command is issued (or 'iprobe' using the legacy + command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device + pairs. Otherwise, specify a 1D array of device addresses + + e.g. + #undef CONFIG_I2C_MULTI_BUS + #define CFG_I2C_NOPROBES {0x50,0x68} + + will skip addresses 0x50 and 0x68 on a board with one I2C bus + + #define CONFIG_I2C_MULTI_BUS + #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}} + + will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1 + - SPI Support: CONFIG_SPI Enables SPI driver (so far only tested with @@ -2209,6 +2239,16 @@ Low Level (hardware related) configuration options: CFG_POCMR2_MASK_ATTRIB: (MPC826x only) Overrides the default PCI memory map in cpu/mpc8260/pci.c if set. +- CONFIG_SPD_EEPROM + Get DDR timing information from an I2C EEPROM. Common with pluggable + memory modules such as SODIMMs + SPD_EEPROM_ADDRESS + I2C address of the SPD EEPROM + +- CFG_SPD_BUS_NUM + If SPD EEPROM is on an I2C bus other than the first one, specify here. + Note that the value must resolve to something your driver can deal with. + - CONFIG_ETHER_ON_FEC[12] Define to enable FEC[12] on a 8xx series processor. diff --git a/common/cmd_i2c.c b/common/cmd_i2c.c index c543bb5..62378af 100644 --- a/common/cmd_i2c.c +++ b/common/cmd_i2c.c @@ -101,8 +101,31 @@ static uchar i2c_mm_last_chip; static uint i2c_mm_last_addr; static uint i2c_mm_last_alen; +/* If only one I2C bus is present, the list of devices to ignore when + * the probe command is issued is represented by a 1D array of addresses. + * When multiple buses are present, the list is an array of bus-address + * pairs. The following macros take care of this */ + #if defined(CFG_I2C_NOPROBES) +#if defined(CONFIG_I2C_MULTI_BUS) +static struct +{ + uchar bus; + uchar addr; +} i2c_no_probes[] = CFG_I2C_NOPROBES; +#define GET_BUS_NUM i2c_get_bus_num() +#define COMPARE_BUS(b,i) (i2c_no_probes[(i)].bus == (b)) +#define COMPARE_ADDR(a,i) (i2c_no_probes[(i)].addr == (a)) +#define NO_PROBE_ADDR(i) i2c_no_probes[(i)].addr +#else /* single bus */ static uchar i2c_no_probes[] = CFG_I2C_NOPROBES; +#define GET_BUS_NUM 0 +#define COMPARE_BUS(b,i) ((b) == 0) /* Make compiler happy */ +#define COMPARE_ADDR(a,i) (i2c_no_probes[(i)] == (a)) +#define NO_PROBE_ADDR(i) i2c_no_probes[(i)] +#endif /* CONFIG_MULTI_BUS */ + +#define NUM_ELEMENTS_NOPROBE (sizeof(i2c_no_probes)/sizeof(i2c_no_probes[0])) #endif static int @@ -538,14 +561,17 @@ int do_i2c_probe (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) int j; #if defined(CFG_I2C_NOPROBES) int k, skip; -#endif + uchar bus = GET_BUS_NUM; +#endif /* NOPROBES */ puts ("Valid chip addresses:"); for(j = 0; j < 128; j++) { #if defined(CFG_I2C_NOPROBES) skip = 0; - for (k = 0; k < sizeof(i2c_no_probes); k++){ - if (j == i2c_no_probes[k]){ + for(k=0; k < NUM_ELEMENTS_NOPROBE; k++) + { + if(COMPARE_BUS(bus, k) && COMPARE_ADDR(j, k)) + { skip = 1; break; } @@ -561,8 +587,11 @@ int do_i2c_probe (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) #if defined(CFG_I2C_NOPROBES) puts ("Excluded chip addresses:"); - for( k = 0; k < sizeof(i2c_no_probes); k++ ) - printf(" %02X", i2c_no_probes[k] ); + for(k=0; k < NUM_ELEMENTS_NOPROBE; k++) + { + if(COMPARE_BUS(bus,k)) + printf(" %02X", NO_PROBE_ADDR(k)); + } putc ('\n'); #endif @@ -873,6 +902,104 @@ int do_sdram ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) } #endif /* CFG_CMD_SDRAM */ +#if defined(CONFIG_I2C_CMD_TREE) +#if defined(CONFIG_I2C_MULTI_BUS) +int do_i2c_bus_num(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +{ + int bus_idx, ret=0; + + if (argc == 1) /* querying current setting */ + { + printf("Current bus is %d\n", i2c_get_bus_num()); + } + else + { + bus_idx = simple_strtoul(argv[1], NULL, 10); + printf("Setting bus to %d\n", bus_idx); + ret = i2c_set_bus_num(bus_idx); + if(ret) + { + printf("Failure changing bus number (%d)\n", ret); + } + } + return ret; +} +#endif /* CONFIG_I2C_MULTI_BUS */ + +int do_i2c_bus_speed(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +{ + int speed, ret=0; + + if (argc == 1) /* querying current speed */ + { + printf("Current bus speed=%d\n", i2c_get_bus_speed()); + } + else + { + speed = simple_strtoul(argv[1], NULL, 10); + printf("Setting bus speed to %d Hz\n", speed); + ret = i2c_set_bus_speed(speed); + if(ret) + { + printf("Failure changing bus speed (%d)\n", ret); + } + } + return ret; +} + +int do_i2c(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[]) +{ +#if defined(CONFIG_I2C_MULTI_BUS) + if(!strncmp(argv[1], "de", 2)) + { + return do_i2c_bus_num(cmdtp, flag, --argc, ++argv); + } +#endif /* CONFIG_I2C_MULTI_BUS */ + if(!strncmp(argv[1], "sp", 2)) + { + return do_i2c_bus_speed(cmdtp, flag, --argc, ++argv); + } + if(!strncmp(argv[1], "md", 2)) + { + return do_i2c_md(cmdtp, flag, --argc, ++argv); + } + if(!strncmp(argv[1], "mm", 2)) + { + return do_i2c_mm(cmdtp, flag, --argc, ++argv); + } + if(!strncmp(argv[1], "mw", 2)) + { + return do_i2c_mw(cmdtp, flag, --argc, ++argv); + } + if(!strncmp(argv[1], "nm", 2)) + { + return do_i2c_nm(cmdtp, flag, --argc, ++argv); + } + if(!strncmp(argv[1], "cr", 2)) + { + return do_i2c_crc(cmdtp, flag, --argc, ++argv); + } + if(!strncmp(argv[1], "pr", 2)) + { + return do_i2c_probe(cmdtp, flag, --argc, ++argv); + } + if(!strncmp(argv[1], "lo", 2)) + { + return do_i2c_loop(cmdtp, flag, --argc, ++argv); + } +#if (CONFIG_COMMANDS & CFG_CMD_SDRAM) + if(!strncmp(argv[1], "sd", 2)) + { + return do_sdram(cmdtp, flag, --argc, ++argv); + } +#endif /* CFG_CMD_SDRAM */ + else + { + printf ("Usage:\n%s\n", cmdtp->usage); + } + return 0; +} +#endif /* CONFIG_I2C_CMD_TREE */ /***************************************************/ @@ -930,4 +1057,26 @@ U_BOOT_CMD( " (valid chip values 50..57)\n" ); #endif + +#if defined(CONFIG_I2C_CMD_TREE) +U_BOOT_CMD( + i2c, 6, 1, do_i2c, + "i2c - I2C sub-system\n", +#if defined(CONFIG_I2C_MULTI_BUS) + "dev [dev] - show or set current I2C bus\n" +#endif /* CONFIG_I2C_MULTI_BUS */ + "i2c speed [speed] - show or set I2C bus speed\n" + "i2c md chip address[.0, .1, .2] [# of objects] - read from I2C device\n" + "i2c mm chip address[.0, .1, .2] - write to I2C device (auto-incrementing)\n" + "i2c mw chip address[.0, .1, .2] value [count] - write to I2C device (fill)\n" + "i2c nm chip address[.0, .1, .2] - write to I2C device (constant address)\n" + "i2c crc32 chip address[.0, .1, .2] count - compute CRC32 checksum\n" + "i2c probe - show devices on the I2C bus\n" + "i2c loop chip address[.0, .1, .2] [# of objects] - looping read of device\n" +#if (CONFIG_COMMANDS & CFG_CMD_SDRAM) + "i2c sdram chip - print SDRAM configuration information\n" +#endif /* CFG_CMD_SDRAM */ +); +#endif /* CONFIG_I2C_CMD_TREE */ + #endif /* CFG_CMD_I2C */ diff --git a/include/i2c.h b/include/i2c.h index 6d39080..97e0061 100644 --- a/include/i2c.h +++ b/include/i2c.h @@ -82,4 +82,49 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len); uchar i2c_reg_read (uchar chip, uchar reg); void i2c_reg_write(uchar chip, uchar reg, uchar val); +/* + * Functions for setting the current I2C bus and its speed + */ + +/* + * i2c_set_bus_num: + * + * Change the active I2C bus. Subsequent read/write calls will + * go to this one. + * + * bus - bus index, zero based + * + * Returns: 0 on success, not 0 on failure + * + */ +int i2c_set_bus_num(uchar bus); + +/* + * i2c_get_bus_num: + * + * Returns index of currently active I2C bus. Zero-based. + */ + +uchar i2c_get_bus_num(void); + +/* + * i2c_set_bus_speed: + * + * Change the speed of the active I2C bus + * + * speed - bus speed in Hz + * + * Returns: 0 on success, not 0 on failure + * + */ +int i2c_set_bus_speed(int); + +/* + * i2c_get_bus_speed: + * + * Returns speed of currently active I2C bus in Hz + */ + +int i2c_get_bus_speed(void); + #endif /* _I2C_H_ */