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@xxxxxxxxxxxxxx>
---
arch/arm/mach-tegra/board-harmony-pcie.c | 24 +++++++++++++++++++++++-
1 files changed, 23 insertions(+), 1 deletions(-)
diff --git a/arch/arm/mach-tegra/board-harmony-pcie.c b/arch/arm/mach-tegra/board-harmony-pcie.c
index f7e7d45..9c27b95 100644
--- a/arch/arm/mach-tegra/board-harmony-pcie.c
+++ b/arch/arm/mach-tegra/board-harmony-pcie.c
@@ -27,13 +27,29 @@
#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);
@@ -49,9 +65,15 @@ err_pcie:
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;
}
-subsys_initcall(harmony_pcie_init);
+/* PCI should be initialized after I2C, mfd and regulators */
+subsys_initcall_sync(harmony_pcie_init);
#endif
--
1.7.3.1
--
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