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| author | Roland Stigge <stigge@antcom.de> | 2012-02-27 20:28:02 +0400 |
|---|---|---|
| committer | Roland Stigge <stigge@antcom.de> | 2012-02-27 20:28:02 +0400 |
| commit | 2707208ee8a80dbbd5426f5aa1a934f766825bb5 (patch) | |
| tree | 91cdaf595011eb7618d9160f9e2cbea890f54509 | |
| parent | 94ed7830cba4dce57b18a2926b5d826bfd184bd6 (diff) | |
| download | linux-2707208ee8a80dbbd5426f5aa1a934f766825bb5.tar.xz | |
ARM: LPC32xx: serial.c: HW bug workaround
This patch fixes a HW bug by flushing RX FIFOs of the UARTs on init. It was
ported from NXP's git.lpclinux.com tree.
Signed-off-by: Roland Stigge <stigge@antcom.de>
Cc: stable@vger.kernel.org
| -rw-r--r-- | arch/arm/mach-lpc32xx/serial.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/arm/mach-lpc32xx/serial.c b/arch/arm/mach-lpc32xx/serial.c index 429cfdbb2b3d..1a3fd4ce0469 100644 --- a/arch/arm/mach-lpc32xx/serial.c +++ b/arch/arm/mach-lpc32xx/serial.c @@ -88,6 +88,7 @@ struct uartinit { char *uart_ck_name; u32 ck_mode_mask; void __iomem *pdiv_clk_reg; + resource_size_t mapbase; }; static struct uartinit uartinit_data[] __initdata = { @@ -97,6 +98,7 @@ static struct uartinit uartinit_data[] __initdata = { .ck_mode_mask = LPC32XX_UART_CLKMODE_LOAD(LPC32XX_UART_CLKMODE_ON, 5), .pdiv_clk_reg = LPC32XX_CLKPWR_UART5_CLK_CTRL, + .mapbase = LPC32XX_UART5_BASE, }, #endif #ifdef CONFIG_ARCH_LPC32XX_UART3_SELECT @@ -105,6 +107,7 @@ static struct uartinit uartinit_data[] __initdata = { .ck_mode_mask = LPC32XX_UART_CLKMODE_LOAD(LPC32XX_UART_CLKMODE_ON, 3), .pdiv_clk_reg = LPC32XX_CLKPWR_UART3_CLK_CTRL, + .mapbase = LPC32XX_UART3_BASE, }, #endif #ifdef CONFIG_ARCH_LPC32XX_UART4_SELECT @@ -113,6 +116,7 @@ static struct uartinit uartinit_data[] __initdata = { .ck_mode_mask = LPC32XX_UART_CLKMODE_LOAD(LPC32XX_UART_CLKMODE_ON, 4), .pdiv_clk_reg = LPC32XX_CLKPWR_UART4_CLK_CTRL, + .mapbase = LPC32XX_UART4_BASE, }, #endif #ifdef CONFIG_ARCH_LPC32XX_UART6_SELECT @@ -121,6 +125,7 @@ static struct uartinit uartinit_data[] __initdata = { .ck_mode_mask = LPC32XX_UART_CLKMODE_LOAD(LPC32XX_UART_CLKMODE_ON, 6), .pdiv_clk_reg = LPC32XX_CLKPWR_UART6_CLK_CTRL, + .mapbase = LPC32XX_UART6_BASE, }, #endif }; @@ -165,6 +170,19 @@ void __init lpc32xx_serial_init(void) /* pre-UART clock divider set to 1 */ __raw_writel(0x0101, uartinit_data[i].pdiv_clk_reg); + + /* + * Force a flush of the RX FIFOs to work around a + * HW bug + */ + puart = uartinit_data[i].mapbase; + __raw_writel(0xC1, LPC32XX_UART_IIR_FCR(puart)); + __raw_writel(0x00, LPC32XX_UART_DLL_FIFO(puart)); + j = LPC32XX_SUART_FIFO_SIZE; + while (j--) + tmp = __raw_readl( + LPC32XX_UART_DLL_FIFO(puart)); + __raw_writel(0, LPC32XX_UART_IIR_FCR(puart)); } /* This needs to be done after all UART clocks are setup */ |