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authorIonela Voinescu <ionela.voinescu@imgtec.com>2015-01-30 17:05:15 +0000
committerPatrick Georgi <pgeorgi@google.com>2015-04-14 12:08:53 +0200
commit256b1c397b21eb42dba3d2c8863ad483ef66d7e2 (patch)
tree0daca303452824c56b9b7cab332435b725a47fa5 /src
parent1d9515ff4c5f2339372ef055da5834827d0c91c4 (diff)
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urara: increase drive strength for SPIM1 MFIOs
This change is made only to make sure there is a good signal strength on the SPIM lines. BUG=chrome-os-partner:31438 TEST=tested on Pistachio bring up board; works properly BRANCH=none Change-Id: I5b9427b14a407746fb5b707fa3b07a1a6774bfb1 Signed-off-by: Stefan Reinauer <reinauer@chromium.org> Original-Commit-Id: e9d953283a5b43bf967128ca73db0e90c2df32df Original-Change-Id: Ia589134cf0557613697d49fb0bdb1848af66f0e8 Original-Signed-off-by: Ionela Voinescu <ionela.voinescu@imgtec.com> Original-Reviewed-on: https://chromium-review.googlesource.com/249732 Original-Reviewed-by: David Hendricks <dhendrix@chromium.org> Reviewed-on: http://review.coreboot.org/9675 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Diffstat (limited to 'src')
-rw-r--r--src/mainboard/google/urara/bootblock.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/src/mainboard/google/urara/bootblock.c b/src/mainboard/google/urara/bootblock.c
index b2f6b70cd4a4..814eb536314e 100644
--- a/src/mainboard/google/urara/bootblock.c
+++ b/src/mainboard/google/urara/bootblock.c
@@ -22,10 +22,22 @@
#include <arch/io.h>
#include <stdint.h>
#include <soc/clocks.h>
+#include <assert.h>
#define PADS_FUNCTION_SELECT0_ADDR (0xB8101C00 + 0xC0)
#define GPIO_BIT_EN_ADDR(bank) (0xB8101C00 + 0x200 + (0x24 * (bank)))
+#define PAD_DRIVE_STRENGTH_ADDR(bank) (0xB8101C00 + 0x120 + (0x4 * (bank)))
+#define MAX_NO_MFIOS 89
+#define PAD_DRIVE_STRENGTH_LENGTH 2
+#define PAD_DRIVE_STRENGTH_MASK 0x3
+
+typedef enum {
+ DRIVE_STRENGTH_2mA = 0,
+ DRIVE_STRENGTH_4mA = 1,
+ DRIVE_STRENGTH_8mA = 2,
+ DRIVE_STRENGTH_12mA = 3
+} drive_strength;
/* MFIO definitions for UART1 */
#define UART1_RXD_MFIO 59
@@ -47,6 +59,21 @@
#define I2C0_DATA_FUNCTION_MASK 0x1
#define I2C0_CLK_FUNCTION_MASK 0x1
+static void pad_drive_strength(u32 pad, drive_strength strength)
+{
+ u32 reg, drive_strength_shift;
+
+ assert(pad <= MAX_NO_MFIOS);
+ assert(!(strength & ~(PAD_DRIVE_STRENGTH_MASK)));
+
+ /* Set drive strength value */
+ drive_strength_shift = (pad % 16) * PAD_DRIVE_STRENGTH_LENGTH;
+ reg = read32(PAD_DRIVE_STRENGTH_ADDR(pad / 16));
+ reg &= ~(PAD_DRIVE_STRENGTH_MASK << drive_strength_shift);
+ reg |= strength << drive_strength_shift;
+ write32(PAD_DRIVE_STRENGTH_ADDR(pad / 16), reg);
+}
+
static void uart1_mfio_setup(void)
{
u32 reg, mfio_mask;
@@ -99,6 +126,14 @@ static void spim1_mfio_setup(void)
*/
reg |= mfio_mask << 16;
write32(GPIO_BIT_EN_ADDR(0), reg);
+
+ /* Set drive strength to maximum for these MFIOs */
+ pad_drive_strength(SPIM1_CS0_MFIO, DRIVE_STRENGTH_12mA);
+ pad_drive_strength(SPIM1_D1_RXD_MFIO, DRIVE_STRENGTH_12mA);
+ pad_drive_strength(SPIM1_D0_TXD_MFIO, DRIVE_STRENGTH_12mA);
+ pad_drive_strength(SPIM1_D2_MFIO, DRIVE_STRENGTH_12mA);
+ pad_drive_strength(SPIM1_D3_MFIO, DRIVE_STRENGTH_12mA);
+ pad_drive_strength(SPIM1_MCLK_MFIO, DRIVE_STRENGTH_12mA);
}
static void i2c0_mfio_setup(void)