pepper: Implement Board Detection mechanism

AM335x-based 'Gumstix Pepper' SBCs and variants use different types of
RAM (DDR2 vs DDR3 with DDR3 being the default).  Detect the board type
by reading the factory-programmed EEPROM [1] and use this to select any
runtime boot options such as RAM type.

[1] http://elinux.org/BeagleBoardPinMux#List_of_Vendor_and_Device_IDs

Signed-off-by: Adam YH Lee <adam.yh.lee@gmail.com>
Signed-off-by: Ash Charles <ashcharles@gmail.com>

diff --git a/board/gumstix/pepper/board.c b/board/gumstix/pepper/board.c
index beb2fac374594fe0d32fb03bf97ce2376affaf39..d76c28bd3cc3ff0a24f78c025ec2a0977704e4e5 100644 (file)
--- a/board/gumstix/pepper/board.c
+++ b/board/gumstix/pepper/board.c
@@ -33,6 +33,46 @@
 DECLARE_GLOBAL_DATA_PTR;
 
 #ifdef CONFIG_SPL_BUILD
+#define OSC    (V_OSCK/1000000)
+
+static const struct ddr_data ddr3_data = {
+       .datardsratio0 = MT41K256M16HA125E_RD_DQS,
+       .datawdsratio0 = MT41K256M16HA125E_WR_DQS,
+       .datafwsratio0 = MT41K256M16HA125E_PHY_FIFO_WE,
+       .datawrsratio0 = MT41K256M16HA125E_PHY_WR_DATA,
+};
+
+static const struct cmd_control ddr3_cmd_ctrl_data = {
+       .cmd0csratio = MT41K256M16HA125E_RATIO,
+       .cmd0iclkout = MT41K256M16HA125E_INVERT_CLKOUT,
+
+       .cmd1csratio = MT41K256M16HA125E_RATIO,
+       .cmd1iclkout = MT41K256M16HA125E_INVERT_CLKOUT,
+
+       .cmd2csratio = MT41K256M16HA125E_RATIO,
+       .cmd2iclkout = MT41K256M16HA125E_INVERT_CLKOUT,
+};
+
+static struct emif_regs ddr3_emif_reg_data = {
+       .sdram_config = MT41K256M16HA125E_EMIF_SDCFG,
+       .ref_ctrl = MT41K256M16HA125E_EMIF_SDREF,
+       .sdram_tim1 = MT41K256M16HA125E_EMIF_TIM1,
+       .sdram_tim2 = MT41K256M16HA125E_EMIF_TIM2,
+       .sdram_tim3 = MT41K256M16HA125E_EMIF_TIM3,
+       .zq_config = MT41K256M16HA125E_ZQ_CFG,
+       .emif_ddr_phy_ctlr_1 = MT41K256M16HA125E_EMIF_READ_LATENCY,
+};
+
+const struct dpll_params dpll_ddr3 = {400, OSC-1, 1, -1, -1, -1, -1};
+
+const struct ctrl_ioregs ioregs_ddr3 = {
+       .cm0ioctl               = MT41K256M16HA125E_IOCTRL_VALUE,
+       .cm1ioctl               = MT41K256M16HA125E_IOCTRL_VALUE,
+       .cm2ioctl               = MT41K256M16HA125E_IOCTRL_VALUE,
+       .dt0ioctl               = MT41K256M16HA125E_IOCTRL_VALUE,
+       .dt1ioctl               = MT41K256M16HA125E_IOCTRL_VALUE,
+};
+
 static const struct ddr_data ddr2_data = {
        .datardsratio0 = MT47H128M16RT25E_RD_DQS,
        .datafwsratio0 = MT47H128M16RT25E_PHY_FIFO_WE,
@@ -56,6 +96,70 @@ static const struct emif_regs ddr2_emif_reg_data = {
        .emif_ddr_phy_ctlr_1 = MT47H128M16RT25E_EMIF_READ_LATENCY,
 };
 
+const struct dpll_params dpll_ddr2 = {266, OSC-1, 1, -1, -1, -1, -1};
+
+const struct ctrl_ioregs ioregs_ddr2 = {
+       .cm0ioctl               = MT47H128M16RT25E_IOCTRL_VALUE,
+       .cm1ioctl               = MT47H128M16RT25E_IOCTRL_VALUE,
+       .cm2ioctl               = MT47H128M16RT25E_IOCTRL_VALUE,
+       .dt0ioctl               = MT47H128M16RT25E_IOCTRL_VALUE,
+       .dt1ioctl               = MT47H128M16RT25E_IOCTRL_VALUE,
+};
+
+static int read_eeprom(struct pepper_board_id *header)
+{
+       if (i2c_probe(CONFIG_SYS_I2C_EEPROM_ADDR)) {
+               return -ENODEV;
+       }
+
+       if (i2c_read(CONFIG_SYS_I2C_EEPROM_ADDR, 0, 1, (uchar *)header,
+               sizeof(struct pepper_board_id))) {
+               return -EIO;
+       }
+
+       return 0;
+}
+
+const struct dpll_params *get_dpll_ddr_params(void)
+{
+       struct pepper_board_id header;
+
+       enable_i2c0_pin_mux();
+       i2c_set_bus_num(0);
+
+       if (read_eeprom(&header) < 0)
+               return &dpll_ddr3;
+
+       switch (header.device_vendor) {
+       case GUMSTIX_PEPPER:
+               return &dpll_ddr2;
+       case GUMSTIX_PEPPER_DVI:
+               return &dpll_ddr3;
+       default:
+               return &dpll_ddr3;
+       }
+}
+
+void sdram_init(void)
+{
+       const struct dpll_params *dpll = get_dpll_ddr_params();
+
+       /*
+        * Here we are assuming PLL clock reveals the type of RAM.
+        * DDR2 = 266
+        * DDR3 = 400
+        * Note that DDR3 is the default.
+        */
+       if (dpll->m == 266) {
+               config_ddr(dpll->m, &ioregs_ddr2, &ddr2_data,
+                       &ddr2_cmd_ctrl_data, &ddr2_emif_reg_data, 0);
+       }
+       else if (dpll->m == 400) {
+               config_ddr(dpll->m, &ioregs_ddr3, &ddr3_data,
+                       &ddr3_cmd_ctrl_data, &ddr3_emif_reg_data, 0);
+       }
+}
+
 #ifdef CONFIG_SPL_OS_BOOT
 int spl_start_uboot(void)
 {
@@ -64,14 +168,6 @@ int spl_start_uboot(void)
 }
 #endif
 
-#define OSC    (V_OSCK/1000000)
-const struct dpll_params dpll_ddr = {266, OSC-1, 1, -1, -1, -1, -1};
-
-const struct dpll_params *get_dpll_ddr_params(void)
-{
-       return &dpll_ddr;
-}
-
 void set_uart_mux_conf(void)
 {
        enable_uart0_pin_mux();
@@ -82,19 +178,7 @@ void set_mux_conf_regs(void)
        enable_board_pin_mux();
 }
 
-const struct ctrl_ioregs ioregs = {
-       .cm0ioctl               = MT47H128M16RT25E_IOCTRL_VALUE,
-       .cm1ioctl               = MT47H128M16RT25E_IOCTRL_VALUE,
-       .cm2ioctl               = MT47H128M16RT25E_IOCTRL_VALUE,
-       .dt0ioctl               = MT47H128M16RT25E_IOCTRL_VALUE,
-       .dt1ioctl               = MT47H128M16RT25E_IOCTRL_VALUE,
-};
 
-void sdram_init(void)
-{
-       config_ddr(266, &ioregs, &ddr2_data,
-                  &ddr2_cmd_ctrl_data, &ddr2_emif_reg_data, 0);
-}
 #endif
 
 int board_init(void)

diff --git a/board/gumstix/pepper/board.h b/board/gumstix/pepper/board.h
index 0512735a7b338781029171d9ab3ae5dba5f2bdd1..a6df3196f4492c7798da7114d77c51fbc4503172 100644 (file)
--- a/board/gumstix/pepper/board.h
+++ b/board/gumstix/pepper/board.h
@@ -9,6 +9,18 @@
 #ifndef _BOARD_H_
 #define _BOARD_H_
 
+#define GUMSTIX_PEPPER         0x30000200
+#define GUMSTIX_PEPPER_DVI     0x31000200
+
+struct pepper_board_id {
+       unsigned int device_vendor;
+       unsigned char revision;
+       unsigned char content;
+       char fab_revision[8];
+       char env_var[16];
+       char en_setting[64];
+};
+
 /*
  * We must be able to enable uart0, for initial output. We then have a
  * main pinmux function that can be overridden to enable all other pinmux that
@@ -16,4 +28,5 @@
  */
 void enable_uart0_pin_mux(void);
 void enable_board_pin_mux(void);
+void enable_i2c0_pin_mux(void);
 #endif

diff --git a/board/gumstix/pepper/mux.c b/board/gumstix/pepper/mux.c
index 50b12666d648c848e8ea363dd59b17e95dc38664..92c73f8df89cb3a028f8fe6c86a94ad72367a1ef 100644 (file)
--- a/board/gumstix/pepper/mux.c
+++ b/board/gumstix/pepper/mux.c
@@ -64,6 +64,11 @@ void enable_uart0_pin_mux(void)
        configure_module_pin_mux(uart0_pin_mux);
 }
 
+void enable_i2c0_pin_mux(void)
+{
+       configure_module_pin_mux(i2c0_pin_mux);
+}
+
 /*
  * Do board-specific muxes.
  */

diff --git a/include/configs/pepper.h b/include/configs/pepper.h
index cc153abaa9ebc14f98bed3889a4c2666777481f5..16149f69d52c80ff1e44676d344b6c0c0fae5fcf 100644 (file)
--- a/include/configs/pepper.h
+++ b/include/configs/pepper.h
@@ -20,6 +20,8 @@
 #undef CONFIG_SYS_PROMPT
 #define CONFIG_SYS_PROMPT              "pepper# "
 
+#define CONFIG_SYS_I2C_EEPROM_ADDR     0x50
+
 /* Mach type */
 #define MACH_TYPE_PEPPER               4207    /* Until the next sync */
 #define CONFIG_MACH_TYPE               MACH_TYPE_PEPPER