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 beb2fac..d76c28b 100644
--- 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 @@
.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 @@
}
#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 @@
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 0512735..a6df319 100644
--- 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 50b1266..92c73f8 100644
--- a/board/gumstix/pepper/mux.c
+++ b/board/gumstix/pepper/mux.c
@@ -64,6 +64,11 @@
configure_module_pin_mux(uart0_pin_mux);
}
+void enable_i2c0_pin_mux(void)
+{
+ configure_module_pin_mux(i2c0_pin_mux);
+}
+
/*
* Do board-specific muxes.
*/