From: hwg <hwg@rock-chips.com>
Date: Thu, 26 Sep 2013 12:25:07 +0000 (+0800)
Subject: modify GRF_IO_CON3 to enhence vmac rmii io strength
X-Git-Tag: firefly_0821_release~6595
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=5a30b697741077a31405c17838893224ff8ac909;p=firefly-linux-kernel-4.4.55.git

modify GRF_IO_CON3 to enhence vmac rmii io strength
---

diff --git a/arch/arm/mach-rk30/board-rk31-sdk-vmac.c b/arch/arm/mach-rk30/board-rk31-sdk-vmac.c
index a29bc9e20b07..324fc09dbeee 100644
--- a/arch/arm/mach-rk30/board-rk31-sdk-vmac.c
+++ b/arch/arm/mach-rk30/board-rk31-sdk-vmac.c
@@ -11,6 +11,7 @@ static int rk30_vmac_register_set(void)
 static int rk30_rmii_io_init(void)
 {
 	int err;
+	long val;
 	printk("enter %s ",__func__);
 	iomux_set(GPIO0_C0);//power pwr
 	iomux_set(GPIO3_D2);//int
@@ -28,8 +29,9 @@ static int rk30_rmii_io_init(void)
 	iomux_set(RMII_CLKOUT);
 
 	//rk3188 gpio3 and sdio drive strength , 
-    grf_writel(0x0f<<16|0x0f,GRF_IO_CON3);
-      
+	val = grf_readl(GRF_IO_CON3);
+	grf_writel(val|(0x0f<<16)|0x0f, GRF_IO_CON3);
+	  
 	//phy power gpio
 	err = gpio_request(PHY_PWR_EN_GPIO, "phy_power_en");
 	if (err) {