diff options
author | Wolfgang Denk <wd@denx.de> | 2012-01-05 16:38:50 +0100 |
---|---|---|
committer | Wolfgang Denk <wd@denx.de> | 2012-01-05 16:38:50 +0100 |
commit | 145afab32c3a049bd646d2eede5f2feba08576c6 (patch) | |
tree | 52aba8f8d68626195027dc3dc190deef84895bfd /board/nvidia/common/uart-spi-switch.c | |
parent | 72ebafbe2bd5044eecbfdaa132390a1421db25be (diff) | |
parent | a747cc0a8c55d69a56a6db80a35cdb48c853447d (diff) | |
download | u-boot-imx-145afab32c3a049bd646d2eede5f2feba08576c6.zip u-boot-imx-145afab32c3a049bd646d2eede5f2feba08576c6.tar.gz u-boot-imx-145afab32c3a049bd646d2eede5f2feba08576c6.tar.bz2 |
Merge branch 'master' of git://git.denx.de/u-boot-arm
* 'master' of git://git.denx.de/u-boot-arm:
tegra2: Optimize out-of-tree build for Ventana.
tegra: Move boards over to use arch-level board UART function
tegra: Add support for UART init in cpu board.c
tegra: Add a function mux feature
tegra: add clock_ll_start_uart() to enable UART prior to reloc
tegra: Move clock_early_init() to arch_cpu_init()
tegra: Move cpu_init_cp15() to arch_cpu_init()
arm: Tegra: Fix Harmony and Ventana builds in u-boot-tegra/master
tegra: Fix build error in plutux, medcom
tegra2: Add Avionic Design Medcom support.
tegra2: Add Avionic Design Plutux support.
tegra2: Add common Avionic Design Tamonten support.
tegra2: Move tegra2_mmc_init() prototype to public header.
tegra2: Change CONFIG_SYS_TEXT_BASE to 0x00108000.
tegra2: Always build with USE_PRIVATE_LIBGCC=yes.
tegra2: Plumb in SPI/UART switch code
tegra2: spi: Support SPI / UART switch
tegra2: Implement SPI / UART GPIO switch
tegra2: Enable SPI environment on Seaboard
tegra2: config: Enable SPI flash on Seaboard
tegra2: spi: Add SPI driver for Tegra2 SOC
tegra2: Add UARTB support
tegra2: Tidy UART selection
arm, davinci: Fix build warnings for cam_enc_4xx
Devkit8000: Switch over to enable_gpmc_cs_config
arm, davinci: Add support for generating AIS images to the Makefile
mkimage: Fix variable length header support
arm, da850evm: Add an SPL for SPI boot
arm, davinci: Add SPL support for DA850 SoCs
sf: Add spi_boot() to allow booting from SPI flash in an SPL
spl: display_options.o is required for SPI flash support in SPL
ARM: omap3: add support to Technexion twister board
ARM: omap3: added common configuration for Technexion TAM3517
vision2: Fix checkpatch warning
Diffstat (limited to 'board/nvidia/common/uart-spi-switch.c')
-rw-r--r-- | board/nvidia/common/uart-spi-switch.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/board/nvidia/common/uart-spi-switch.c b/board/nvidia/common/uart-spi-switch.c new file mode 100644 index 0000000..23aa0b9 --- /dev/null +++ b/board/nvidia/common/uart-spi-switch.c @@ -0,0 +1,138 @@ +/* + * Copyright (c) 2011 The Chromium OS Authors. + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <ns16550.h> +#include <asm/gpio.h> +#include <asm/arch/pinmux.h> +#include <asm/arch/uart-spi-switch.h> +#include <asm/arch/tegra2.h> +#include <asm/arch/tegra2_spi.h> + + +/* position of the UART/SPI select switch */ +enum spi_uart_switch { + SWITCH_UNKNOWN, + SWITCH_SPI, + SWITCH_UART, + SWITCH_BOTH +}; + +/* Information about the spi/uart switch */ +struct spi_uart { + int gpio; /* GPIO to control switch */ + NS16550_t regs; /* Address of UART affected */ + u32 port; /* Port number of UART affected */ +}; + +static struct spi_uart local; +static enum spi_uart_switch switch_pos; /* Current switch position */ + + +static void get_config(struct spi_uart *config) +{ +#if defined CONFIG_SPI_CORRUPTS_UART + config->gpio = CONFIG_UART_DISABLE_GPIO; + config->regs = (NS16550_t)CONFIG_SPI_CORRUPTS_UART; + config->port = CONFIG_SPI_CORRUPTS_UART_NR; +#else + config->gpio = -1; +#endif +} + +/* + * Init the UART / SPI switch. This can be called before relocation so we must + * not access BSS. + */ +void gpio_early_init_uart(void) +{ + struct spi_uart config; + + get_config(&config); + if (config.gpio != -1) { + /* Cannot provide a label prior to relocation */ + gpio_request(config.gpio, NULL); + gpio_direction_output(config.gpio, 0); + } +} + +/* + * Configure the UART / SPI switch. + */ +void gpio_config_uart(void) +{ + get_config(&local); + if (local.gpio != -1) { + gpio_direction_output(local.gpio, 0); + switch_pos = SWITCH_UART; + } else { + /* + * If we're here we don't have a SPI switch; go ahead and + * enable the SPI now. We didn't in spi_init() so we wouldn't + * kill the UART. + */ + pinmux_set_func(PINGRP_GMC, PMUX_FUNC_SFLASH); + switch_pos = SWITCH_BOTH; + } +} + +static void spi_uart_switch(struct spi_uart *config, + enum spi_uart_switch new_pos) +{ + if (switch_pos == SWITCH_BOTH || new_pos == switch_pos) + return; + + /* if the UART was selected, allow it to drain */ + if (switch_pos == SWITCH_UART) + NS16550_drain(config->regs, config->port); + + /* We need to dynamically change the pinmux, shared w/UART RXD/CTS */ + pinmux_set_func(PINGRP_GMC, new_pos == SWITCH_SPI ? + PMUX_FUNC_SFLASH : PMUX_FUNC_UARTD); + + /* + * On Seaboard, MOSI/MISO are shared w/UART. + * Use GPIO I3 (UART_DISABLE) to tristate UART during SPI activity. + * Enable UART later (cs_deactivate) so we can use it for U-Boot comms. + */ + gpio_direction_output(config->gpio, new_pos == SWITCH_SPI); + switch_pos = new_pos; + + /* if the SPI was selected, clear any junk bytes in the UART */ + if (switch_pos == SWITCH_UART) { + /* TODO: What if it is part-way through clocking in junk? */ + udelay(100); + NS16550_clear(config->regs, config->port); + } +} + +void pinmux_select_uart(NS16550_t regs) +{ + /* Also prevents calling spi_uart_switch() before relocation */ + if (regs == local.regs) + spi_uart_switch(&local, SWITCH_UART); +} + +void pinmux_select_spi(void) +{ + spi_uart_switch(&local, SWITCH_SPI); +} |