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authorWolfgang Denk <wd@denx.de>2012-01-05 16:38:50 +0100
committerWolfgang Denk <wd@denx.de>2012-01-05 16:38:50 +0100
commit145afab32c3a049bd646d2eede5f2feba08576c6 (patch)
tree52aba8f8d68626195027dc3dc190deef84895bfd /board/nvidia/common/uart-spi-switch.c
parent72ebafbe2bd5044eecbfdaa132390a1421db25be (diff)
parenta747cc0a8c55d69a56a6db80a35cdb48c853447d (diff)
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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.c138
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);
+}