From f905293d655cbb8be833261ef390aaba71b44307 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Tue, 11 Jul 2017 14:26:01 +0200 Subject: [PATCH] clk: gemini: Fix reset regression commit e2860e1f62f2 ("serial: 8250_of: Add reset support") introduced reset support for the 8250_of driver. However it unconditionally uses the assert/deassert pair to deassert reset on the device at probe and assert it at remove. This does not work with systems that have a self-deasserting reset controller, such as Gemini, that recently added a reset controller. As a result, the console will not probe on the Gemini with this message: Serial: 8250/16550 driver, 1 ports, IRQ sharing disabled of_serial: probe of 42000000.serial failed with error -524 This (-ENOTSUPP) is the error code returned by the deassert() operation on self-deasserting reset controllers. To work around this, implement dummy .assert() and .deassert() operations in the Gemini combined clock and reset controller. This fixes the issue on this system. Cc: Joel Stanley Cc: Greg Kroah-Hartman Cc: linux-serial@vger.kernel.org Fixes: e2860e1f62f2 ("serial: 8250_of: Add reset support") Signed-off-by: Linus Walleij Acked-by: Philipp Zabel Signed-off-by: Stephen Boyd --- drivers/clk/clk-gemini.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/clk/clk-gemini.c b/drivers/clk/clk-gemini.c index c391a49aaaff..b4cf2f699a21 100644 --- a/drivers/clk/clk-gemini.c +++ b/drivers/clk/clk-gemini.c @@ -237,6 +237,18 @@ static int gemini_reset(struct reset_controller_dev *rcdev, BIT(GEMINI_RESET_CPU1) | BIT(id)); } +static int gemini_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + return 0; +} + +static int gemini_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + return 0; +} + static int gemini_reset_status(struct reset_controller_dev *rcdev, unsigned long id) { @@ -253,6 +265,8 @@ static int gemini_reset_status(struct reset_controller_dev *rcdev, static const struct reset_control_ops gemini_reset_ops = { .reset = gemini_reset, + .assert = gemini_reset_assert, + .deassert = gemini_reset_deassert, .status = gemini_reset_status, };