af015f956c
Tested on the following boards: ALFA AP96 TL-MR3220 v1 TL-WR1043ND v1 TL-WR2543ND v1 TL-WR703N v1 TL-WR741ND v1 TL-WR741ND v4 WNDR3700 v1 WZR-HP-G300NH SVN-Revision: 29868
43 lines
1.3 KiB
Diff
43 lines
1.3 KiB
Diff
From 48b7e765e6e097d20d809fadd17a4355d26ad6d5 Mon Sep 17 00:00:00 2001
|
|
From: Gabor Juhos <juhosg@openwrt.org>
|
|
Date: Wed, 11 Jan 2012 20:06:35 +0100
|
|
Subject: [PATCH 1/7] spi/ath79: add delay between SCK changes
|
|
|
|
The driver uses the "as fast as it can" approach
|
|
to drive the SCK signal. However this does not
|
|
work with certain low speed SPI chips (e.g. the
|
|
PCF2123 RTC chip). Add per-bit slowdowns in order
|
|
to be able to use the driver with such chips as
|
|
well.
|
|
|
|
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
|
|
---
|
|
drivers/spi/spi-ath79.c | 8 ++++++++
|
|
1 files changed, 8 insertions(+), 0 deletions(-)
|
|
|
|
--- a/drivers/spi/spi-ath79.c
|
|
+++ b/drivers/spi/spi-ath79.c
|
|
@@ -52,6 +52,12 @@ static inline struct ath79_spi *ath79_sp
|
|
return spi_master_get_devdata(spi->master);
|
|
}
|
|
|
|
+static inline void ath79_spi_delay(unsigned nsecs)
|
|
+{
|
|
+ if (nsecs)
|
|
+ ndelay(nsecs);
|
|
+}
|
|
+
|
|
static void ath79_spi_chipselect(struct spi_device *spi, int is_active)
|
|
{
|
|
struct ath79_spi *sp = ath79_spidev_to_sp(spi);
|
|
@@ -184,7 +190,9 @@ static u32 ath79_spi_txrx_mode0(struct s
|
|
|
|
/* setup MSB (to slave) on trailing edge */
|
|
ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, out);
|
|
+ ath79_spi_delay(nsecs);
|
|
ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, out | AR71XX_SPI_IOC_CLK);
|
|
+ ath79_spi_delay(nsecs);
|
|
|
|
word <<= 1;
|
|
}
|