diff options
author | Krzysztof Kozlowski <k.kozlowski@samsung.com> | 2014-12-05 15:15:34 +0100 |
---|---|---|
committer | Michael Turquette <mturquette@linaro.org> | 2014-12-17 07:31:51 -0800 |
commit | f1e9203e2366164b832d8a6ce10134de8c575178 (patch) | |
tree | b63f8a883579d364856014b7b122fb0fbc581d5f | |
parent | 83ccc4670477e7722d4654ca44b4b7004fcaada9 (diff) |
clk: samsung: Fix Exynos 5420 pinctrl setup and clock disable failure due to domain being gatedclk-for-linus-3.19
Audio subsystem clocks are located in separate block. On Exynos 5420 if
clock for this block (from main clock domain) 'mau_epll' is gated then
any read or write to audss registers will block.
This kind of boot hang was observed on Arndale Octa and Peach Pi/Pit
after introducing runtime PM to pl330 DMA driver. After that commit the
'mau_epll' was gated, because the "amba" clock was disabled and there
were no more users of mau_epll.
The system hang on one of steps:
1. Disabling unused clocks from audss block.
2. During audss GPIO setup (just before probing i2s0 because
samsung_pinmux_setup() tried to access memory from audss block which was
gated.
Add a workaround for this by enabling the 'mau_epll' clock in probe.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
-rw-r--r-- | drivers/clk/samsung/clk-exynos-audss.c | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/drivers/clk/samsung/clk-exynos-audss.c b/drivers/clk/samsung/clk-exynos-audss.c index b50469faf70c..f7eff82738ab 100644 --- a/drivers/clk/samsung/clk-exynos-audss.c +++ b/drivers/clk/samsung/clk-exynos-audss.c @@ -29,6 +29,13 @@ static DEFINE_SPINLOCK(lock); static struct clk **clk_table; static void __iomem *reg_base; static struct clk_onecell_data clk_data; +/* + * On Exynos5420 this will be a clock which has to be enabled before any + * access to audss registers. Typically a child of EPLL. + * + * On other platforms this will be -ENODEV. + */ +static struct clk *epll; #define ASS_CLK_SRC 0x0 #define ASS_CLK_DIV 0x4 @@ -98,6 +105,8 @@ static int exynos_audss_clk_probe(struct platform_device *pdev) dev_err(&pdev->dev, "failed to map audss registers\n"); return PTR_ERR(reg_base); } + /* EPLL don't have to be enabled for boards other than Exynos5420 */ + epll = ERR_PTR(-ENODEV); clk_table = devm_kzalloc(&pdev->dev, sizeof(struct clk *) * EXYNOS_AUDSS_MAX_CLKS, @@ -115,8 +124,20 @@ static int exynos_audss_clk_probe(struct platform_device *pdev) pll_in = devm_clk_get(&pdev->dev, "pll_in"); if (!IS_ERR(pll_ref)) mout_audss_p[0] = __clk_get_name(pll_ref); - if (!IS_ERR(pll_in)) + if (!IS_ERR(pll_in)) { mout_audss_p[1] = __clk_get_name(pll_in); + + if (variant == TYPE_EXYNOS5420) { + epll = pll_in; + + ret = clk_prepare_enable(epll); + if (ret) { + dev_err(&pdev->dev, + "failed to prepare the epll clock\n"); + return ret; + } + } + } clk_table[EXYNOS_MOUT_AUDSS] = clk_register_mux(NULL, "mout_audss", mout_audss_p, ARRAY_SIZE(mout_audss_p), CLK_SET_RATE_NO_REPARENT, @@ -203,6 +224,9 @@ unregister: clk_unregister(clk_table[i]); } + if (!IS_ERR(epll)) + clk_disable_unprepare(epll); + return ret; } @@ -221,6 +245,9 @@ static int exynos_audss_clk_remove(struct platform_device *pdev) clk_unregister(clk_table[i]); } + if (!IS_ERR(epll)) + clk_disable_unprepare(epll); + return 0; } |