da850: Add RMII support for EMAC

This patch is a port of the work by Sudhakar Rajeshekhara in commit
ab3effbcad8851cc65dc5241a01c064d2030a3b2 of
git://arago-project.org/git/people/sandeep/u-boot-davinci.git.

The da850 UI board has on it an RMII PHY which can be used if the MDC line
to the MII PHY on the baseboard is disabled and the RMII PHY is enabled by
configuring the values of some GPIO pins on the IO expander of the UI board.
This patch implements disabling that line via GPIO2[6], configuring the UI
board's IO expander and setting only the pinmux settings that are needed for
RMII operation.

Tested on da850evm by adding a define for CONFIG_DRIVER_TI_EMAC_USE_RMII.

Signed-off-by: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
CC: Sandeep Paulraj <s-paulraj@ti.com>
CC: Ben Warren <biggerbadderben@gmail.com>
CC: Mike Frysinger <vapier@gentoo.org>
CC: Sughosh Ganu <urwithsughosh@gmail.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>

2 files changed, 122 insertions, 4 deletions

diff --git a/board/davinci/da8xxevm/common.c b/board/davinci/da8xxevm/common.c
index 36bf69394..2d9a64bff 100644
--- a/board/davinci/da8xxevm/common.c
+++ b/board/davinci/da8xxevm/common.c
@@ -53,3 +53,17 @@ int da8xx_configure_lpsc_items(const struct lpsc_resource *item,
 
 	return 0;
 }
+
+#if defined(CONFIG_DRIVER_TI_EMAC) && defined(CONFIG_MACH_DAVINCI_DA850_EVM)
+void da850_emac_mii_mode_sel(int mode_sel)
+{
+	int val;
+
+	val = readl(&davinci_syscfg_regs->cfgchip3);
+	if (mode_sel == 0)
+		val &= ~(1 << 8);
+	else
+		val |= (1 << 8);
+	writel(val, &davinci_syscfg_regs->cfgchip3);
+}
+#endif
diff --git a/board/davinci/da8xxevm/da850evm.c b/board/davinci/da8xxevm/da850evm.c
index 8c9ff7c63..291757c1f 100644
--- a/board/davinci/da8xxevm/da850evm.c
+++ b/board/davinci/da8xxevm/da850evm.c
@@ -54,6 +54,15 @@ static const struct pinmux_config uart_pins[] = {
 
 #ifdef CONFIG_DRIVER_TI_EMAC
 static const struct pinmux_config emac_pins[] = {
+#ifdef CONFIG_DRIVER_TI_EMAC_USE_RMII
+	{ pinmux(14), 8, 2 },
+	{ pinmux(14), 8, 3 },
+	{ pinmux(14), 8, 4 },
+	{ pinmux(14), 8, 5 },
+	{ pinmux(14), 8, 6 },
+	{ pinmux(14), 8, 7 },
+	{ pinmux(15), 8, 1 },
+#else /* ! CONFIG_DRIVER_TI_EMAC_USE_RMII */
 	{ pinmux(2), 8, 1 },
 	{ pinmux(2), 8, 2 },
 	{ pinmux(2), 8, 3 },
@@ -69,10 +78,10 @@ static const struct pinmux_config emac_pins[] = {
 	{ pinmux(3), 8, 5 },
 	{ pinmux(3), 8, 6 },
 	{ pinmux(3), 8, 7 },
+#endif /* CONFIG_DRIVER_TI_EMAC_USE_RMII */
 	{ pinmux(4), 8, 0 },
 	{ pinmux(4), 8, 1 }
 };
-#endif /* CONFIG_DRIVER_TI_EMAC */
 
 /* I2C pin muxer settings */
 static const struct pinmux_config i2c_pins[] = {
@@ -99,6 +108,13 @@ const struct pinmux_config nand_pins[] = {
 };
 #endif
 
+#ifdef CONFIG_DRIVER_TI_EMAC_USE_RMII
+#define HAS_RMII 1
+#else
+#define HAS_RMII 0
+#endif
+#endif /* CONFIG_DRIVER_TI_EMAC */
+
 static const struct pinmux_resource pinmuxes[] = {
 #ifdef CONFIG_SPI_FLASH
 	PINMUX_ITEM(spi1_pins),
@@ -203,9 +219,8 @@ int board_init(void)
 #ifdef CONFIG_DRIVER_TI_EMAC
 	if (davinci_configure_pin_mux(emac_pins, ARRAY_SIZE(emac_pins)) != 0)
 		return 1;
-	/* set cfgchip3 to select MII */
-	writel(readl(&davinci_syscfg_regs->cfgchip3) & ~(1 << 8),
-			     &davinci_syscfg_regs->cfgchip3);
+
+	da850_emac_mii_mode_sel(HAS_RMII);
 #endif /* CONFIG_DRIVER_TI_EMAC */
 
 	/* enable the console UART */
@@ -218,11 +233,100 @@ int board_init(void)
 
 #ifdef CONFIG_DRIVER_TI_EMAC
 
+#ifdef CONFIG_DRIVER_TI_EMAC_USE_RMII
+/**
+ * rmii_hw_init
+ *
+ * DA850/OMAP-L138 EVM can interface to a daughter card for
+ * additional features. This card has an I2C GPIO Expander TCA6416
+ * to select the required functions like camera, RMII Ethernet,
+ * character LCD, video.
+ *
+ * Initialization of the expander involves configuring the
+ * polarity and direction of the ports. P07-P05 are used here.
+ * These ports are connected to a Mux chip which enables only one
+ * functionality at a time.
+ *
+ * For RMII phy to respond, the MII MDIO clock has to be  disabled
+ * since both the PHY devices have address as zero. The MII MDIO
+ * clock is controlled via GPIO2[6].
+ *
+ * This code is valid for Beta version of the hardware
+ */
+int rmii_hw_init(void)
+{
+	const struct pinmux_config gpio_pins[] = {
+		{ pinmux(6), 8, 1 }
+	};
+	u_int8_t buf[2];
+	unsigned int temp;
+	int ret;
+
+	/* PinMux for GPIO */
+	if (davinci_configure_pin_mux(gpio_pins, ARRAY_SIZE(gpio_pins)) != 0)
+		return 1;
+
+	/* I2C Exapnder configuration */
+	/* Set polarity to non-inverted */
+	buf[0] = 0x0;
+	buf[1] = 0x0;
+	ret = i2c_write(CONFIG_SYS_I2C_EXPANDER_ADDR, 4, 1, buf, 2);
+	if (ret) {
+		printf("\nExpander @ 0x%02x write FAILED!!!\n",
+				CONFIG_SYS_I2C_EXPANDER_ADDR);
+		return ret;
+	}
+
+	/* Configure P07-P05 as outputs */
+	buf[0] = 0x1f;
+	buf[1] = 0xff;
+	ret = i2c_write(CONFIG_SYS_I2C_EXPANDER_ADDR, 6, 1, buf, 2);
+	if (ret) {
+		printf("\nExpander @ 0x%02x write FAILED!!!\n",
+				CONFIG_SYS_I2C_EXPANDER_ADDR);
+	}
+
+	/* For Ethernet RMII selection
+	 * P07(SelA)=0
+	 * P06(SelB)=1
+	 * P05(SelC)=1
+	 */
+	if (i2c_read(CONFIG_SYS_I2C_EXPANDER_ADDR, 2, 1, buf, 1)) {
+		printf("\nExpander @ 0x%02x read FAILED!!!\n",
+				CONFIG_SYS_I2C_EXPANDER_ADDR);
+	}
+
+	buf[0] &= 0x1f;
+	buf[0] |= (0 << 7) | (1 << 6) | (1 << 5);
+	if (i2c_write(CONFIG_SYS_I2C_EXPANDER_ADDR, 2, 1, buf, 1)) {
+		printf("\nExpander @ 0x%02x write FAILED!!!\n",
+				CONFIG_SYS_I2C_EXPANDER_ADDR);
+	}
+
+	/* Set the output as high */
+	temp = REG(GPIO_BANK2_REG_SET_ADDR);
+	temp |= (0x01 << 6);
+	REG(GPIO_BANK2_REG_SET_ADDR) = temp;
+
+	/* Set the GPIO direction as output */
+	temp = REG(GPIO_BANK2_REG_DIR_ADDR);
+	temp &= ~(0x01 << 6);
+	REG(GPIO_BANK2_REG_DIR_ADDR) = temp;
+
+	return 0;
+}
+#endif /* CONFIG_DRIVER_TI_EMAC_USE_RMII */
+
 /*
  * Initializes on-board ethernet controllers.
  */
 int board_eth_init(bd_t *bis)
 {
+#ifdef CONFIG_DRIVER_TI_EMAC_USE_RMII
+	/* Select RMII fucntion through the expander */
+	if (rmii_hw_init())
+		printf("RMII hardware init failed!!!\n");
+#endif
 	if (!davinci_emac_initialize()) {
 		printf("Error: Ethernet init failed!\n");
 		return -1;