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author | Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com> | 2011-06-13 10:11:44 +0200 |
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committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-06-16 12:01:58 -0700 |
commit | 1a7d4369b3fe1f8e5efe7f11a1c482055693852f (patch) | |
tree | a0365dc6548078275869ac1efdc982aa0471769c /arch | |
parent | c16d51a32bbb61ac8fd96f78b5ce2fccfe0fb4c3 (diff) | |
download | lwn-1a7d4369b3fe1f8e5efe7f11a1c482055693852f.tar.gz lwn-1a7d4369b3fe1f8e5efe7f11a1c482055693852f.zip |
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.c | 16 | ||||
-rw-r--r-- | arch/arm/mach-ux500/board-mop500.c | 54 |
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 = { |