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Diffstat (limited to 'target/linux/ar71xx/patches-3.2/201-spi-ath79-add-delay-between-SCK-changes.patch')
-rw-r--r--target/linux/ar71xx/patches-3.2/201-spi-ath79-add-delay-between-SCK-changes.patch100
1 files changed, 90 insertions, 10 deletions
diff --git a/target/linux/ar71xx/patches-3.2/201-spi-ath79-add-delay-between-SCK-changes.patch b/target/linux/ar71xx/patches-3.2/201-spi-ath79-add-delay-between-SCK-changes.patch
index c2681f9a5..9294133d4 100644
--- a/target/linux/ar71xx/patches-3.2/201-spi-ath79-add-delay-between-SCK-changes.patch
+++ b/target/linux/ar71xx/patches-3.2/201-spi-ath79-add-delay-between-SCK-changes.patch
@@ -1,4 +1,4 @@
-From 48b7e765e6e097d20d809fadd17a4355d26ad6d5 Mon Sep 17 00:00:00 2001
+From 8e948c035dd7983eccc3a889f2497e64044f3a31 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
@@ -12,31 +12,111 @@ well.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
---
- drivers/spi/spi-ath79.c | 8 ++++++++
- 1 files changed, 8 insertions(+), 0 deletions(-)
+ drivers/spi/spi-ath79.c | 44 +++++++++++++++++++++++++++++++++++++++++++-
+ 1 files changed, 43 insertions(+), 1 deletions(-)
--- a/drivers/spi/spi-ath79.c
+++ b/drivers/spi/spi-ath79.c
-@@ -52,6 +52,12 @@ static inline struct ath79_spi *ath79_sp
+@@ -24,17 +24,24 @@
+ #include <linux/spi/spi_bitbang.h>
+ #include <linux/bitops.h>
+ #include <linux/gpio.h>
++#include <linux/clk.h>
++#include <linux/err.h>
+
+ #include <asm/mach-ath79/ar71xx_regs.h>
+ #include <asm/mach-ath79/ath79_spi_platform.h>
+
+ #define DRV_NAME "ath79-spi"
+
++#define ATH79_SPI_RRW_DELAY_FACTOR 12000
++#define MHZ (1000 * 1000)
++
+ struct ath79_spi {
+ struct spi_bitbang bitbang;
+ u32 ioc_base;
+ u32 reg_ctrl;
+ void __iomem *base;
++ struct clk *clk;
++ unsigned rrw_delay;
+ };
+
+ static inline u32 ath79_spi_rr(struct ath79_spi *sp, unsigned reg)
+@@ -52,6 +59,12 @@ static inline struct ath79_spi *ath79_sp
return spi_master_get_devdata(spi->master);
}
-+static inline void ath79_spi_delay(unsigned nsecs)
++static inline void ath79_spi_delay(struct ath79_spi *sp, unsigned nsecs)
+{
-+ if (nsecs)
-+ ndelay(nsecs);
++ if (nsecs > sp->rrw_delay)
++ ndelay(nsecs - sp->rrw_delay);
+}
+
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
+@@ -184,7 +197,9 @@ 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_delay(sp, nsecs);
ath79_spi_wr(sp, AR71XX_SPI_REG_IOC, out | AR71XX_SPI_IOC_CLK);
-+ ath79_spi_delay(nsecs);
++ ath79_spi_delay(sp, nsecs);
word <<= 1;
}
+@@ -198,6 +213,7 @@ static __devinit int ath79_spi_probe(str
+ struct ath79_spi *sp;
+ struct ath79_spi_platform_data *pdata;
+ struct resource *r;
++ unsigned long rate;
+ int ret;
+
+ master = spi_alloc_master(&pdev->dev, sizeof(*sp));
+@@ -239,12 +255,36 @@ static __devinit int ath79_spi_probe(str
+ goto err_put_master;
+ }
+
++ sp->clk = clk_get(&pdev->dev, "ahb");
++ if (IS_ERR(sp->clk)) {
++ ret = PTR_ERR(sp->clk);
++ goto err_unmap;
++ }
++
++ ret = clk_enable(sp->clk);
++ if (ret)
++ goto err_clk_put;
++
++ rate = DIV_ROUND_UP(clk_get_rate(sp->clk), MHZ);
++ if (!rate) {
++ ret = -EINVAL;
++ goto err_clk_disable;
++ }
++
++ sp->rrw_delay = ATH79_SPI_RRW_DELAY_FACTOR / rate;
++ dev_dbg(&pdev->dev, "register read/write delay is %u nsecs\n",
++ sp->rrw_delay);
++
+ ret = spi_bitbang_start(&sp->bitbang);
+ if (ret)
+- goto err_unmap;
++ goto err_clk_disable;
+
+ return 0;
+
++err_clk_disable:
++ clk_disable(sp->clk);
++err_clk_put:
++ clk_put(sp->clk);
+ err_unmap:
+ iounmap(sp->base);
+ err_put_master:
+@@ -259,6 +299,8 @@ static __devexit int ath79_spi_remove(st
+ struct ath79_spi *sp = platform_get_drvdata(pdev);
+
+ spi_bitbang_stop(&sp->bitbang);
++ clk_disable(sp->clk);
++ clk_put(sp->clk);
+ iounmap(sp->base);
+ platform_set_drvdata(pdev, NULL);
+ spi_master_put(sp->bitbang.master);