Audio subsystem clocks are located in separate block. If clock for this
block (from main clock domain) 'mau_epll' is gated then any read or
write to audss registers will block.
This was observed on Exynos 5420 platforms (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 disabling
unused clocks from audss block.
Unfortunately the 'mau_epll' clock is not parent of some of audss clocks.
Whenever system wants to operate on audss clocks it has to enable epll
clock. The solution reuses common clk-gate/divider/mux code and duplicates
clk_register_*() functions.
Additionally this patch fixes memory leak of clock gate/divider/mux
structures. The leak exists in generic clk_register_*() functions. Patch
replaces them with custom code with managed allocation.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
Reported-by: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx>
Reported-by: Kevin Hilman <khilman@xxxxxxxxxx>
Tested-by: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx>
---
drivers/clk/samsung/clk-exynos-audss.c | 339 +++++++++++++++++++++++++++++----
1 file changed, 303 insertions(+), 36 deletions(-)
diff --git a/drivers/clk/samsung/clk-exynos-audss.c b/drivers/clk/samsung/clk-exynos-audss.c
index 7c4368e75ede..0460618807e0 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
@@ -75,6 +82,247 @@ static const struct of_device_id exynos_audss_clk_of_match[] = {
{},
};
+static int pll_clk_enable(void)
+{
+ if (!IS_ERR(epll))
+ return clk_enable(epll);
+
+ return 0;
+}
+
+static void pll_clk_disable(void)
+{
+ if (!IS_ERR(epll))
+ clk_disable(epll);
+}
+
+static int audss_clk_gate_enable(struct clk_hw *hw)
+{
+ int ret;
+
+ ret = pll_clk_enable();
+ if (ret)
+ return ret;
+
+ ret = clk_gate_ops.enable(hw);
+
+ pll_clk_disable();
+
+ return ret;
+}
+
+static void audss_clk_gate_disable(struct clk_hw *hw)
+{
+ int ret;
+
+ ret = pll_clk_enable();
+ if (ret)
+ return;
+
+ clk_gate_ops.disable(hw);
+
+ pll_clk_disable();
+}
+
+static int audss_clk_gate_is_enabled(struct clk_hw *hw)
+{
+ int ret;
+
+ ret = pll_clk_enable();
+ if (ret)
+ return ret;
+
+ ret = clk_gate_ops.is_enabled(hw);
+
+ pll_clk_disable();
+
+ return ret;
+}
+
+static const struct clk_ops audss_clk_gate_ops = {
+ .enable = audss_clk_gate_enable,
+ .disable = audss_clk_gate_disable,
+ .is_enabled = audss_clk_gate_is_enabled,
+};
+
+/*
+ * A simplified copy of clk-gate.c:clk_register_gate() to mimic
+ * clk-gate behavior while using customized ops.
+ */
+static struct clk *audss_clk_register_gate(struct device *dev, const char *name,
+ const char *parent_name, unsigned long flags,
+ void __iomem *reg, u8 bit_idx)
+{
+ struct clk_gate *gate;
+ struct clk_init_data init;
+
+ gate = devm_kzalloc(dev, sizeof(struct clk_gate), GFP_KERNEL);
+ if (!gate)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.ops = &audss_clk_gate_ops;
+ init.flags = flags | CLK_IS_BASIC;
+ init.parent_names = (parent_name ? &parent_name : NULL);
+ init.num_parents = (parent_name ? 1 : 0);
+
+ /* struct clk_gate assignments */
+ gate->reg = reg;
+ gate->bit_idx = bit_idx;
+ gate->lock = &lock;
+ gate->hw.init = &init;
+
+ return clk_register(dev, &gate->hw);
+}
+
+static unsigned long audss_clk_divider_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ unsigned long ret;
+
+ ret = pll_clk_enable();
+ if (ret) {
+ WARN(ret, "Could not enable epll clock\n");
+ return parent_rate;
+ }
+
+ ret = clk_divider_ops.recalc_rate(hw, parent_rate);
+
+ pll_clk_disable();
+
+ return ret;
+}
+
+static long audss_clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ return clk_divider_ops.round_rate(hw, rate, prate);
+}
+
+static int audss_clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ int ret;
+
+ ret = pll_clk_enable();
+ if (ret)
+ return ret;
+
+ ret = clk_divider_ops.set_rate(hw, rate, parent_rate);
+
+ pll_clk_disable();
+
+ return ret;
+}
+
+static const struct clk_ops audss_clk_divider_ops = {
+ .recalc_rate = audss_clk_divider_recalc_rate,
+ .round_rate = audss_clk_divider_round_rate,
+ .set_rate = audss_clk_divider_set_rate,
+};
+
+/*
+ * A simplified copy of clk-divider.c:clk_register_divider() to mimic
+ * clk-divider behavior while using customized ops.
+ */
+static struct clk *audss_clk_register_divider(struct device *dev,
+ const char *name, const char *parent_name, unsigned long flags,
+ void __iomem *reg, u8 shift, u8 width)
+{
+ struct clk_divider *div;
+ struct clk_init_data init;
+
+ div = devm_kzalloc(dev, sizeof(struct clk_divider), GFP_KERNEL);
+ if (!div)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.ops = &audss_clk_divider_ops;
+ init.flags = flags | CLK_IS_BASIC;
+ init.parent_names = (parent_name ? &parent_name : NULL);
+ init.num_parents = (parent_name ? 1 : 0);
+
+ /* struct clk_divider assignments */
+ div->reg = reg;
+ div->shift = shift;
+ div->width = width;
+ div->lock = &lock;
+ div->hw.init = &init;
+
+ return clk_register(dev, &div->hw);
+}
+
+static u8 audss_clk_mux_get_parent(struct clk_hw *hw)
+{
+ u8 parent;
+ int ret;
+
+ ret = pll_clk_enable();
+ if (ret) {
+ WARN(ret, "Could not enable epll clock\n");
+ return ret; /* Just like clk_mux_get_parent() */
+ }
+
+ parent = clk_mux_ops.get_parent(hw);
+
+ pll_clk_disable();
+
+ return parent;
+}
+
+static int audss_clk_mux_set_parent(struct clk_hw *hw, u8 index)
+{
+ int ret;
+
+ ret = pll_clk_enable();
+ if (ret)
+ return ret;
+
+ ret = clk_mux_ops.set_parent(hw, index);
+
+ pll_clk_disable();
+
+ return ret;
+}
+
+static const struct clk_ops audss_clk_mux_ops = {
+ .get_parent = audss_clk_mux_get_parent,
+ .set_parent = audss_clk_mux_set_parent,
+ .determine_rate = __clk_mux_determine_rate,
+};
+
+/*
+ * A simplified copy of clk-mux.c:clk_register_mux_table() to mimic
+ * clk-mux behavior while using customized ops.
+ */
+static struct clk *audss_clk_register_mux(struct device *dev, const char *name,
+ const char **parent_names, u8 num_parents, unsigned long flags,
+ void __iomem *reg, u8 shift, u8 width)
+{
+ struct clk_mux *mux;
+ struct clk_init_data init;
+ u32 mask = BIT(width) - 1;
+
+ mux = devm_kzalloc(dev, sizeof(struct clk_mux), GFP_KERNEL);
+ if (!mux)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.ops = &audss_clk_mux_ops;
+ init.flags = flags | CLK_IS_BASIC;
+ init.parent_names = parent_names;
+ init.num_parents = num_parents;
+
+ /* struct clk_mux assignments */
+ mux->reg = reg;
+ mux->shift = shift;
+ mux->mask = mask;
+ mux->lock = &lock;
+ mux->hw.init = &init;
+
+ return clk_register(dev, &mux->hw);
+}
+
/* register exynos_audss clocks */
static int exynos_audss_clk_probe(struct platform_device *pdev)
{
@@ -98,6 +346,8 @@ 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,
@@ -115,12 +365,24 @@ 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);
- clk_table[EXYNOS_MOUT_AUDSS] = clk_register_mux(NULL, "mout_audss",
- mout_audss_p, ARRAY_SIZE(mout_audss_p),
- CLK_SET_RATE_NO_REPARENT,
- reg_base + ASS_CLK_SRC, 0, 1, 0, &lock);
+
+ if (variant == TYPE_EXYNOS5420) {
+ epll = pll_in;
+
+ ret = clk_prepare(epll);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "failed to prepare the epll clock\n");
+ return ret;
+ }
+ }
+ }
+
+ clk_table[EXYNOS_MOUT_AUDSS] = audss_clk_register_mux(&pdev->dev,
+ "mout_audss", mout_audss_p, ARRAY_SIZE(mout_audss_p),
+ CLK_SET_RATE_NO_REPARENT, reg_base + ASS_CLK_SRC, 0, 1);
cdclk = devm_clk_get(&pdev->dev, "cdclk");
sclk_audio = devm_clk_get(&pdev->dev, "sclk_audio");
@@ -128,50 +390,49 @@ static int exynos_audss_clk_probe(struct platform_device *pdev)
mout_i2s_p[1] = __clk_get_name(cdclk);
if (!IS_ERR(sclk_audio))
mout_i2s_p[2] = __clk_get_name(sclk_audio);
- clk_table[EXYNOS_MOUT_I2S] = clk_register_mux(NULL, "mout_i2s",
- mout_i2s_p, ARRAY_SIZE(mout_i2s_p),
- CLK_SET_RATE_NO_REPARENT,
- reg_base + ASS_CLK_SRC, 2, 2, 0, &lock);
+ clk_table[EXYNOS_MOUT_I2S] = audss_clk_register_mux(&pdev->dev,
+ "mout_i2s", mout_i2s_p, ARRAY_SIZE(mout_i2s_p),
+ CLK_SET_RATE_NO_REPARENT, reg_base + ASS_CLK_SRC, 2, 2);
- clk_table[EXYNOS_DOUT_SRP] = clk_register_divider(NULL, "dout_srp",
- "mout_audss", 0, reg_base + ASS_CLK_DIV, 0, 4,
- 0, &lock);
+ clk_table[EXYNOS_DOUT_SRP] = audss_clk_register_divider(&pdev->dev,
+ "dout_srp", "mout_audss", 0,
+ reg_base + ASS_CLK_DIV, 0, 4);
- clk_table[EXYNOS_DOUT_AUD_BUS] = clk_register_divider(NULL,
- "dout_aud_bus", "dout_srp", 0,
- reg_base + ASS_CLK_DIV, 4, 4, 0, &lock);
+ clk_table[EXYNOS_DOUT_AUD_BUS] = audss_clk_register_divider(&pdev->dev,
+ "dout_aud_bus", "dout_srp", 0,
+ reg_base + ASS_CLK_DIV, 4, 4);
- clk_table[EXYNOS_DOUT_I2S] = clk_register_divider(NULL, "dout_i2s",
- "mout_i2s", 0, reg_base + ASS_CLK_DIV, 8, 4, 0,
- &lock);
+ clk_table[EXYNOS_DOUT_I2S] = audss_clk_register_divider(&pdev->dev,
+ "dout_i2s", "mout_i2s", 0,
+ reg_base + ASS_CLK_DIV, 8, 4);
- clk_table[EXYNOS_SRP_CLK] = clk_register_gate(NULL, "srp_clk",
- "dout_srp", CLK_SET_RATE_PARENT,
- reg_base + ASS_CLK_GATE, 0, 0, &lock);
+ clk_table[EXYNOS_SRP_CLK] = audss_clk_register_gate(&pdev->dev,
+ "srp_clk", "dout_srp", CLK_SET_RATE_PARENT,
+ reg_base + ASS_CLK_GATE, 0);
- clk_table[EXYNOS_I2S_BUS] = clk_register_gate(NULL, "i2s_bus",
- "dout_aud_bus", CLK_SET_RATE_PARENT,
- reg_base + ASS_CLK_GATE, 2, 0, &lock);
+ clk_table[EXYNOS_I2S_BUS] = audss_clk_register_gate(&pdev->dev,
+ "i2s_bus", "dout_aud_bus", CLK_SET_RATE_PARENT,
+ reg_base + ASS_CLK_GATE, 2);
- clk_table[EXYNOS_SCLK_I2S] = clk_register_gate(NULL, "sclk_i2s",
- "dout_i2s", CLK_SET_RATE_PARENT,
- reg_base + ASS_CLK_GATE, 3, 0, &lock);
+ clk_table[EXYNOS_SCLK_I2S] = audss_clk_register_gate(&pdev->dev,
+ "sclk_i2s", "dout_i2s", CLK_SET_RATE_PARENT,
+ reg_base + ASS_CLK_GATE, 3);
- clk_table[EXYNOS_PCM_BUS] = clk_register_gate(NULL, "pcm_bus",
- "sclk_pcm", CLK_SET_RATE_PARENT,
- reg_base + ASS_CLK_GATE, 4, 0, &lock);
+ clk_table[EXYNOS_PCM_BUS] = audss_clk_register_gate(&pdev->dev,
+ "pcm_bus", "sclk_pcm", CLK_SET_RATE_PARENT,
+ reg_base + ASS_CLK_GATE, 4);
sclk_pcm_in = devm_clk_get(&pdev->dev, "sclk_pcm_in");
if (!IS_ERR(sclk_pcm_in))
sclk_pcm_p = __clk_get_name(sclk_pcm_in);
- clk_table[EXYNOS_SCLK_PCM] = clk_register_gate(NULL, "sclk_pcm",
- sclk_pcm_p, CLK_SET_RATE_PARENT,
- reg_base + ASS_CLK_GATE, 5, 0, &lock);
+ clk_table[EXYNOS_SCLK_PCM] = audss_clk_register_gate(&pdev->dev,
+ "sclk_pcm", sclk_pcm_p, CLK_SET_RATE_PARENT,
+ reg_base + ASS_CLK_GATE, 5);
if (variant == TYPE_EXYNOS5420) {
- clk_table[EXYNOS_ADMA] = clk_register_gate(NULL, "adma",
- "dout_srp", CLK_SET_RATE_PARENT,
- reg_base + ASS_CLK_GATE, 9, 0, &lock);
+ clk_table[EXYNOS_ADMA] = audss_clk_register_gate(&pdev->dev,
+ "adma", "dout_srp", CLK_SET_RATE_PARENT,
+ reg_base + ASS_CLK_GATE, 9);
}
for (i = 0; i < clk_data.clk_num; i++) {
@@ -198,6 +459,9 @@ static int exynos_audss_clk_probe(struct platform_device *pdev)
return 0;
unregister:
+ if (!IS_ERR(epll))
+ clk_unprepare(epll);
+
for (i = 0; i < clk_data.clk_num; i++) {
if (!IS_ERR(clk_table[i]))
clk_unregister(clk_table[i]);
@@ -214,6 +478,9 @@ static int exynos_audss_clk_remove(struct platform_device *pdev)
unregister_syscore_ops(&exynos_audss_clk_syscore_ops);
#endif
+ if (!IS_ERR(epll))
+ clk_unprepare(epll);
+
of_clk_del_provider(pdev->dev.of_node);
for (i = 0; i < clk_data.clk_num; i++) {
--
1.9.1
--
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