kernel-ark/arch/arm/mach-tegra/board-harmony-pcie.c
Mike Rapoport ce005cf450 ARM: tegra: harmony: update PCI-e initialization sequence
On Harmony board PCI-e subsystem can be enabled only after certain
voltage regulators are on. One of the regulators is an internal
regulator on the PMIC and another one is controlled by a PMIC GPIO.
Addition of the voltage control to the Harmony PCI-e initialization
allows booting of kernel with CONFIG_TEGRA_PCI even if the PMIC driver
is not loaded. In this case the PCI-e initialization will fail
gracefully intead of hanging the system.

Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: Olof Johansson <olof@lixom.net>
2011-03-15 14:28:32 -07:00

80 lines
1.9 KiB
C

/*
* arch/arm/mach-tegra/board-harmony-pcie.c
*
* Copyright (C) 2010 CompuLab, Ltd.
* Mike Rapoport <mike@compulab.co.il>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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.
*
*/
#include <linux/kernel.h>
#include <linux/gpio.h>
#include <linux/err.h>
#include <linux/regulator/consumer.h>
#include <asm/mach-types.h>
#include <mach/pinmux.h>
#include "board.h"
#ifdef CONFIG_TEGRA_PCI
/* GPIO 3 of the PMIC */
#define EN_VDD_1V05_GPIO (TEGRA_NR_GPIOS + 2)
static int __init harmony_pcie_init(void)
{
struct regulator *regulator = NULL;
int err;
if (!machine_is_harmony())
return 0;
err = gpio_request(EN_VDD_1V05_GPIO, "EN_VDD_1V05");
if (err)
return err;
gpio_direction_output(EN_VDD_1V05_GPIO, 1);
regulator = regulator_get(NULL, "pex_clk");
if (IS_ERR_OR_NULL(regulator))
goto err_reg;
regulator_enable(regulator);
tegra_pinmux_set_tristate(TEGRA_PINGROUP_GPV, TEGRA_TRI_NORMAL);
tegra_pinmux_set_tristate(TEGRA_PINGROUP_SLXA, TEGRA_TRI_NORMAL);
tegra_pinmux_set_tristate(TEGRA_PINGROUP_SLXK, TEGRA_TRI_NORMAL);
err = tegra_pcie_init(true, true);
if (err)
goto err_pcie;
return 0;
err_pcie:
tegra_pinmux_set_tristate(TEGRA_PINGROUP_GPV, TEGRA_TRI_TRISTATE);
tegra_pinmux_set_tristate(TEGRA_PINGROUP_SLXA, TEGRA_TRI_TRISTATE);
tegra_pinmux_set_tristate(TEGRA_PINGROUP_SLXK, TEGRA_TRI_TRISTATE);
regulator_disable(regulator);
regulator_put(regulator);
err_reg:
gpio_free(EN_VDD_1V05_GPIO);
return err;
}
/* PCI should be initialized after I2C, mfd and regulators */
subsys_initcall_sync(harmony_pcie_init);
#endif