From 1f174a1a2cdebc65138e6ed1448b842e73200bb5 Mon Sep 17 00:00:00 2001 From: Dinh Nguyen Date: Mon, 17 Sep 2018 09:52:14 -0500 Subject: clocksource/drivers/dw_apb: Add reset control Add code to retrieve the reset property from the dw-apb timers and if the property is available, the safe operation is to assert the timer into reset, and followed by a deassert of the timer reset (brings the timer out of reset). This patch is needed for systems where the bootloader has left the timer not used in reset. - Trivial conflict with commit a74bd1ad7a: "Convert to using %pOFn instead of device_node.name" Reported-by: Marek Vasut Signed-off-by: Dinh Nguyen Signed-off-by: Daniel Lezcano --- drivers/clocksource/dw_apb_timer_of.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/clocksource/dw_apb_timer_of.c b/drivers/clocksource/dw_apb_timer_of.c index fabaa29cc3a4..db410acd8964 100644 --- a/drivers/clocksource/dw_apb_timer_of.c +++ b/drivers/clocksource/dw_apb_timer_of.c @@ -22,6 +22,7 @@ #include #include #include +#include #include static void __init timer_get_base_and_rate(struct device_node *np, @@ -29,12 +30,23 @@ static void __init timer_get_base_and_rate(struct device_node *np, { struct clk *timer_clk; struct clk *pclk; + struct reset_control *rstc; *base = of_iomap(np, 0); if (!*base) panic("Unable to map regs for %pOFn", np); + /* + * Reset the timer if the reset control is available, wiping + * out the state the firmware may have left it + */ + rstc = of_reset_control_get(np, NULL); + if (!IS_ERR(rstc)) { + reset_control_assert(rstc); + reset_control_deassert(rstc); + } + /* * Not all implementations use a periphal clock, so don't panic * if it's not present -- cgit v1.2.3