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authorShreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>2011-06-13 10:11:44 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2011-06-16 12:01:58 -0700
commit1a7d4369b3fe1f8e5efe7f11a1c482055693852f (patch)
treea0365dc6548078275869ac1efdc982aa0471769c /arch
parentc16d51a32bbb61ac8fd96f78b5ce2fccfe0fb4c3 (diff)
amba pl011: platform data for reg lockup and glitch v2
This patch provides platform data for following - uart reset function to assist uart register lockup workaround - init/exit function to fix glitch in the tx pin in tty_open when tty port0 is opened a glitch is seen in the tx line of uart0. This happens in pl011_startup() when tx fifo interrupt is provoked into asserting. Now uart0 pins are enabled (alt function) only when init is complete and turned back to gpio when closed. Signed-off-by: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/mach-ux500/board-mop500-pins.c16
-rw-r--r--arch/arm/mach-ux500/board-mop500.c54
2 files changed, 66 insertions, 4 deletions
diff --git a/arch/arm/mach-ux500/board-mop500-pins.c b/arch/arm/mach-ux500/board-mop500-pins.c
index fd4cf1ca5efd..70cdbd60596a 100644
--- a/arch/arm/mach-ux500/board-mop500-pins.c
+++ b/arch/arm/mach-ux500/board-mop500-pins.c
@@ -110,10 +110,18 @@ static pin_cfg_t mop500_pins_common[] = {
GPIO168_KP_O0,
/* UART */
- GPIO0_U0_CTSn | PIN_INPUT_PULLUP,
- GPIO1_U0_RTSn | PIN_OUTPUT_HIGH,
- GPIO2_U0_RXD | PIN_INPUT_PULLUP,
- GPIO3_U0_TXD | PIN_OUTPUT_HIGH,
+ /* uart-0 pins gpio configuration should be
+ * kept intact to prevent glitch in tx line
+ * when tty dev is opened. Later these pins
+ * are configured to uart mop500_pins_uart0
+ *
+ * It will be replaced with uart configuration
+ * once the issue is solved.
+ */
+ GPIO0_GPIO | PIN_INPUT_PULLUP,
+ GPIO1_GPIO | PIN_OUTPUT_HIGH,
+ GPIO2_GPIO | PIN_INPUT_PULLUP,
+ GPIO3_GPIO | PIN_OUTPUT_HIGH,
GPIO29_U2_RXD | PIN_INPUT_PULLUP,
GPIO30_U2_TXD | PIN_OUTPUT_HIGH,
diff --git a/arch/arm/mach-ux500/board-mop500.c b/arch/arm/mach-ux500/board-mop500.c
index bb26f40493e6..2a08c07dec6d 100644
--- a/arch/arm/mach-ux500/board-mop500.c
+++ b/arch/arm/mach-ux500/board-mop500.c
@@ -27,18 +27,21 @@
#include <linux/leds-lp5521.h>
#include <linux/input.h>
#include <linux/gpio_keys.h>
+#include <linux/delay.h>
#include <asm/mach-types.h>
#include <asm/mach/arch.h>
#include <plat/i2c.h>
#include <plat/ste_dma40.h>
+#include <plat/pincfg.h>
#include <mach/hardware.h>
#include <mach/setup.h>
#include <mach/devices.h>
#include <mach/irqs.h>
+#include "pins-db8500.h"
#include "ste-dma40-db8500.h"
#include "devices-db8500.h"
#include "board-mop500.h"
@@ -393,12 +396,63 @@ static struct stedma40_chan_cfg uart2_dma_cfg_tx = {
};
#endif
+
+static pin_cfg_t mop500_pins_uart0[] = {
+ GPIO0_U0_CTSn | PIN_INPUT_PULLUP,
+ GPIO1_U0_RTSn | PIN_OUTPUT_HIGH,
+ GPIO2_U0_RXD | PIN_INPUT_PULLUP,
+ GPIO3_U0_TXD | PIN_OUTPUT_HIGH,
+};
+
+#define PRCC_K_SOFTRST_SET 0x18
+#define PRCC_K_SOFTRST_CLEAR 0x1C
+static void ux500_uart0_reset(void)
+{
+ void __iomem *prcc_rst_set, *prcc_rst_clr;
+
+ prcc_rst_set = (void __iomem *)IO_ADDRESS(U8500_CLKRST1_BASE +
+ PRCC_K_SOFTRST_SET);
+ prcc_rst_clr = (void __iomem *)IO_ADDRESS(U8500_CLKRST1_BASE +
+ PRCC_K_SOFTRST_CLEAR);
+
+ /* Activate soft reset PRCC_K_SOFTRST_CLEAR */
+ writel((readl(prcc_rst_clr) | 0x1), prcc_rst_clr);
+ udelay(1);
+
+ /* Release soft reset PRCC_K_SOFTRST_SET */
+ writel((readl(prcc_rst_set) | 0x1), prcc_rst_set);
+ udelay(1);
+}
+
+static void ux500_uart0_init(void)
+{
+ int ret;
+
+ ret = nmk_config_pins(mop500_pins_uart0,
+ ARRAY_SIZE(mop500_pins_uart0));
+ if (ret < 0)
+ pr_err("pl011: uart pins_enable failed\n");
+}
+
+static void ux500_uart0_exit(void)
+{
+ int ret;
+
+ ret = nmk_config_pins_sleep(mop500_pins_uart0,
+ ARRAY_SIZE(mop500_pins_uart0));
+ if (ret < 0)
+ pr_err("pl011: uart pins_disable failed\n");
+}
+
static struct amba_pl011_data uart0_plat = {
#ifdef CONFIG_STE_DMA40
.dma_filter = stedma40_filter,
.dma_rx_param = &uart0_dma_cfg_rx,
.dma_tx_param = &uart0_dma_cfg_tx,
#endif
+ .init = ux500_uart0_init,
+ .exit = ux500_uart0_exit,
+ .reset = ux500_uart0_reset,
};
static struct amba_pl011_data uart1_plat = {