From 8067042ad9543b410b7dc355ec312c2b61979eec Mon Sep 17 00:00:00 2001 From: Ezequiel Garcia Date: Tue, 4 Nov 2014 10:21:32 -0300 Subject: [PATCH] watchdog: orion: Use the reference clock on Armada 375 SoC The 25 MHz reference clock has better stability so its use is prefered over the core clock. Change the Armada 375 clock initialization to use this reference clock. To ensure the driver is compatible with an old devicetree, also provide a fallback path which will silently return to the previous behavior. While here, add the clock specification to the binding documentation. Acked-by: Jason Cooper Acked-by: Gregory CLEMENT Acked-by: Wim Van Sebroeck Reviewed-by: Thomas Petazzoni Tested-by: Thomas Petazzoni Signed-off-by: Ezequiel Garcia Signed-off-by: Daniel Lezcano --- .../devicetree/bindings/watchdog/marvel.txt | 13 ++++++ drivers/watchdog/orion_wdt.c | 42 ++++++++++++++++++- 2 files changed, 54 insertions(+), 1 deletion(-) diff --git a/Documentation/devicetree/bindings/watchdog/marvel.txt b/Documentation/devicetree/bindings/watchdog/marvel.txt index 97223fddb7bd..858ed9221ac4 100644 --- a/Documentation/devicetree/bindings/watchdog/marvel.txt +++ b/Documentation/devicetree/bindings/watchdog/marvel.txt @@ -17,6 +17,18 @@ For "marvell,armada-375-wdt" and "marvell,armada-380-wdt": - reg : A third entry is mandatory and should contain the shared mask/unmask RSTOUT address. +Clocks required for compatibles = "marvell,orion-wdt", + "marvell,armada-370-wdt": +- clocks : Must contain a single entry describing the clock input + +Clocks required for compatibles = "marvell,armada-xp-wdt" + "marvell,armada-375-wdt" + "marvell,armada-380-wdt": +- clocks : Must contain an entry for each entry in clock-names. +- clock-names : Must include the following entries: + "nbclk" (L2/coherency fabric clock), + "fixed" (Reference 25 MHz fixed-clock). + Optional properties: - interrupts : Contains the IRQ for watchdog expiration @@ -30,4 +42,5 @@ Example: interrupts = <3>; timeout-sec = <10>; status = "okay"; + clocks = <&gate_clk 7>; }; diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c index 00d0741228fc..8cb1ff3bcd90 100644 --- a/drivers/watchdog/orion_wdt.c +++ b/drivers/watchdog/orion_wdt.c @@ -114,6 +114,46 @@ static int armada370_wdt_clock_init(struct platform_device *pdev, return 0; } +static int armada375_wdt_clock_init(struct platform_device *pdev, + struct orion_watchdog *dev) +{ + int ret; + + dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed"); + if (!IS_ERR(dev->clk)) { + ret = clk_prepare_enable(dev->clk); + if (ret) { + clk_put(dev->clk); + return ret; + } + + atomic_io_modify(dev->reg + TIMER_CTRL, + WDT_AXP_FIXED_ENABLE_BIT, + WDT_AXP_FIXED_ENABLE_BIT); + dev->clk_rate = clk_get_rate(dev->clk); + + return 0; + } + + /* Mandatory fallback for proper devicetree backward compatibility */ + dev->clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(dev->clk)) + return PTR_ERR(dev->clk); + + ret = clk_prepare_enable(dev->clk); + if (ret) { + clk_put(dev->clk); + return ret; + } + + atomic_io_modify(dev->reg + TIMER_CTRL, + WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT), + WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT)); + dev->clk_rate = clk_get_rate(dev->clk) / WDT_A370_RATIO; + + return 0; +} + static int armadaxp_wdt_clock_init(struct platform_device *pdev, struct orion_watchdog *dev) { @@ -394,7 +434,7 @@ static const struct orion_watchdog_data armada375_data = { .rstout_mask_bit = BIT(10), .wdt_enable_bit = BIT(8), .wdt_counter_offset = 0x34, - .clock_init = armada370_wdt_clock_init, + .clock_init = armada375_wdt_clock_init, .enabled = armada375_enabled, .start = armada375_start, .stop = armada375_stop,