[PATCH v2 2/4] clk: iproc: Add support for Cygnus audio clocks

From: Ray Jui
Date: Mon Nov 23 2015 - 12:50:48 EST


From: Simran Rai <ssimran@xxxxxxxxxxxx>

This patch adds support for Broadcom Cygnus audio PLL and leaf
clocks

Signed-off-by: Simran Rai <ssimran@xxxxxxxxxxxx>
Reviewed-by: Scott Branden <sbranden@xxxxxxxxxxxx>
Signed-off-by: Ray Jui <rjui@xxxxxxxxxxxx>
---
drivers/clk/bcm/clk-cygnus.c | 59 ++++++++++++++++++++++++++++++++++
drivers/clk/bcm/clk-iproc-pll.c | 41 ++++++++++++++++++++---
drivers/clk/bcm/clk-iproc.h | 21 ++++++++++++
include/dt-bindings/clock/bcm-cygnus.h | 6 ++++
4 files changed, 122 insertions(+), 5 deletions(-)

diff --git a/drivers/clk/bcm/clk-cygnus.c b/drivers/clk/bcm/clk-cygnus.c
index 3a228b6..464fdc4 100644
--- a/drivers/clk/bcm/clk-cygnus.c
+++ b/drivers/clk/bcm/clk-cygnus.c
@@ -268,3 +268,62 @@ static void __init cygnus_asiu_init(struct device_node *node)
iproc_asiu_setup(node, asiu_div, asiu_gate, ARRAY_SIZE(asiu_div));
}
CLK_OF_DECLARE(cygnus_asiu_clk, "brcm,cygnus-asiu-clk", cygnus_asiu_init);
+
+/*
+ * AUDIO PLL VCO frequency parameter table
+ *
+ * PLL output frequency = ((ndiv_int + ndiv_frac / 2^20) *
+ * (parent clock rate / pdiv)
+ *
+ * On Cygnus, parent is the 25MHz oscillator
+ */
+static const struct iproc_pll_vco_param audiopll_vco_params[] = {
+ /* rate (Hz) ndiv_int ndiv_frac pdiv */
+ { 1354750204UL, 54, 199238, 1 },
+ { 1769470191UL, 70, 816639, 1 },
+};
+
+static const struct iproc_pll_ctrl audiopll = {
+ .flags = IPROC_CLK_PLL_NEEDS_SW_CFG | IPROC_CLK_PLL_HAS_NDIV_FRAC |
+ IPROC_CLK_PLL_USER_MODE_ON | IPROC_CLK_PLL_RESET_ACTIVE_LOW,
+ .reset = RESET_VAL(0x5c, 0, 1),
+ .dig_filter = DF_VAL(0x48, 0, 3, 6, 4, 3, 3),
+ .sw_ctrl = SW_CTRL_VAL(0x4, 0),
+ .ndiv_int = REG_VAL(0x8, 0, 10),
+ .ndiv_frac = REG_VAL(0x8, 10, 20),
+ .pdiv = REG_VAL(0x44, 0, 4),
+ .vco_ctrl = VCO_CTRL_VAL(0x0c, 0x10),
+ .status = REG_VAL(0x54, 0, 1),
+ .macro_mode = REG_VAL(0x0, 0, 3),
+};
+
+static const struct iproc_clk_ctrl audiopll_clk[] = {
+ [BCM_CYGNUS_AUDIOPLL_CH0] = {
+ .channel = BCM_CYGNUS_AUDIOPLL_CH0,
+ .flags = IPROC_CLK_AON |
+ IPROC_CLK_MCLK_DIV_BY_2,
+ .enable = ENABLE_VAL(0x14, 8, 10, 9),
+ .mdiv = REG_VAL(0x14, 0, 8),
+ },
+ [BCM_CYGNUS_AUDIOPLL_CH1] = {
+ .channel = BCM_CYGNUS_AUDIOPLL_CH1,
+ .flags = IPROC_CLK_AON,
+ .enable = ENABLE_VAL(0x18, 8, 10, 9),
+ .mdiv = REG_VAL(0x18, 0, 8),
+ },
+ [BCM_CYGNUS_AUDIOPLL_CH2] = {
+ .channel = BCM_CYGNUS_AUDIOPLL_CH2,
+ .flags = IPROC_CLK_AON,
+ .enable = ENABLE_VAL(0x1c, 8, 10, 9),
+ .mdiv = REG_VAL(0x1c, 0, 8),
+ },
+};
+
+static void __init cygnus_audiopll_clk_init(struct device_node *node)
+{
+ iproc_pll_clk_setup(node, &audiopll, audiopll_vco_params,
+ ARRAY_SIZE(audiopll_vco_params), audiopll_clk,
+ ARRAY_SIZE(audiopll_clk));
+}
+CLK_OF_DECLARE(cygnus_audiopll, "brcm,cygnus-audiopll",
+ cygnus_audiopll_clk_init);
diff --git a/drivers/clk/bcm/clk-iproc-pll.c b/drivers/clk/bcm/clk-iproc-pll.c
index afd5891..fd492a5 100644
--- a/drivers/clk/bcm/clk-iproc-pll.c
+++ b/drivers/clk/bcm/clk-iproc-pll.c
@@ -25,6 +25,12 @@
#define PLL_VCO_HIGH_SHIFT 19
#define PLL_VCO_LOW_SHIFT 30

+/*
+ * PLL MACRO_SELECT modes 0 to 5 choose pre-calculated PLL output frequencies
+ * from a look-up table. Mode 7 allows user to manipulate PLL clock dividers
+ */
+#define PLL_USER_MODE 7
+
/* number of delay loops waiting for PLL to lock */
#define LOCK_DELAY 100

@@ -215,7 +221,10 @@ static void __pll_put_in_reset(struct iproc_pll *pll)
const struct iproc_pll_reset_ctrl *reset = &ctrl->reset;

val = readl(pll->control_base + reset->offset);
- val &= ~(1 << reset->reset_shift | 1 << reset->p_reset_shift);
+ if (ctrl->flags & IPROC_CLK_PLL_RESET_ACTIVE_LOW)
+ val |= BIT(reset->reset_shift) | BIT(reset->p_reset_shift);
+ else
+ val &= ~(BIT(reset->reset_shift) | BIT(reset->p_reset_shift));
iproc_pll_write(pll, pll->control_base, reset->offset, val);
}

@@ -236,7 +245,10 @@ static void __pll_bring_out_reset(struct iproc_pll *pll, unsigned int kp,
iproc_pll_write(pll, pll->control_base, dig_filter->offset, val);

val = readl(pll->control_base + reset->offset);
- val |= 1 << reset->reset_shift | 1 << reset->p_reset_shift;
+ if (ctrl->flags & IPROC_CLK_PLL_RESET_ACTIVE_LOW)
+ val &= ~(BIT(reset->reset_shift) | BIT(reset->p_reset_shift));
+ else
+ val |= BIT(reset->reset_shift) | BIT(reset->p_reset_shift);
iproc_pll_write(pll, pll->control_base, reset->offset, val);
}

@@ -292,6 +304,16 @@ static int pll_set_rate(struct iproc_clk *clk, unsigned int rate_index,
/* put PLL in reset */
__pll_put_in_reset(pll);

+ /* set PLL in user mode before modifying PLL controls */
+ if (ctrl->flags & IPROC_CLK_PLL_USER_MODE_ON) {
+ val = readl(pll->control_base + ctrl->macro_mode.offset);
+ val &= ~(bit_mask(ctrl->macro_mode.width) <<
+ ctrl->macro_mode.shift);
+ val |= PLL_USER_MODE << ctrl->macro_mode.shift;
+ iproc_pll_write(pll, pll->control_base,
+ ctrl->macro_mode.offset, val);
+ }
+
iproc_pll_write(pll, pll->control_base, ctrl->vco_ctrl.u_offset, 0);

val = readl(pll->control_base + ctrl->vco_ctrl.l_offset);
@@ -505,7 +527,10 @@ static unsigned long iproc_clk_recalc_rate(struct clk_hw *hw,
if (mdiv == 0)
mdiv = 256;

- clk->rate = parent_rate / mdiv;
+ if (ctrl->flags & IPROC_CLK_MCLK_DIV_BY_2)
+ clk->rate = parent_rate / (mdiv * 2);
+ else
+ clk->rate = parent_rate / mdiv;

return clk->rate;
}
@@ -543,7 +568,10 @@ static int iproc_clk_set_rate(struct clk_hw *hw, unsigned long rate,
if (rate == 0 || parent_rate == 0)
return -EINVAL;

- div = DIV_ROUND_UP(parent_rate, rate);
+ if (ctrl->flags & IPROC_CLK_MCLK_DIV_BY_2)
+ div = DIV_ROUND_UP(parent_rate, rate * 2);
+ else
+ div = DIV_ROUND_UP(parent_rate, rate);
if (div > 256)
return -EINVAL;

@@ -555,7 +583,10 @@ static int iproc_clk_set_rate(struct clk_hw *hw, unsigned long rate,
val |= div << ctrl->mdiv.shift;
}
iproc_pll_write(pll, pll->control_base, ctrl->mdiv.offset, val);
- clk->rate = parent_rate / div;
+ if (ctrl->flags & IPROC_CLK_MCLK_DIV_BY_2)
+ clk->rate = parent_rate / (div * 2);
+ else
+ clk->rate = parent_rate / div;

return 0;
}
diff --git a/drivers/clk/bcm/clk-iproc.h b/drivers/clk/bcm/clk-iproc.h
index 8988de7..febae11 100644
--- a/drivers/clk/bcm/clk-iproc.h
+++ b/drivers/clk/bcm/clk-iproc.h
@@ -61,6 +61,26 @@
#define IPROC_CLK_PLL_SPLIT_STAT_CTRL BIT(6)

/*
+ * Some PLLs have an additional divide by 2 in master clock calculation;
+ * MCLK = VCO_freq / (Mdiv * 2). Identify this to let the driver know
+ * of modified calculations
+ */
+#define IPROC_CLK_MCLK_DIV_BY_2 BIT(7)
+
+/*
+ * Some PLLs provide a look up table for the leaf clock frequencies and
+ * auto calculates VCO frequency parameters based on the provided leaf
+ * clock frequencies. They have a user mode that allows the divider
+ * controls to be determined by the user
+ */
+#define IPROC_CLK_PLL_USER_MODE_ON BIT(8)
+
+/*
+ * Some PLLs have an active low reset
+ */
+#define IPROC_CLK_PLL_RESET_ACTIVE_LOW BIT(9)
+
+/*
* Parameters for VCO frequency configuration
*
* VCO frequency =
@@ -149,6 +169,7 @@ struct iproc_pll_ctrl {
struct iproc_clk_reg_op pdiv;
struct iproc_pll_vco_ctrl vco_ctrl;
struct iproc_clk_reg_op status;
+ struct iproc_clk_reg_op macro_mode;
};

/*
diff --git a/include/dt-bindings/clock/bcm-cygnus.h b/include/dt-bindings/clock/bcm-cygnus.h
index 32fbc47..62ac5d7 100644
--- a/include/dt-bindings/clock/bcm-cygnus.h
+++ b/include/dt-bindings/clock/bcm-cygnus.h
@@ -65,4 +65,10 @@
#define BCM_CYGNUS_ASIU_ADC_CLK 1
#define BCM_CYGNUS_ASIU_PWM_CLK 2

+/* AUDIO clock ID */
+#define BCM_CYGNUS_AUDIOPLL 0
+#define BCM_CYGNUS_AUDIOPLL_CH0 1
+#define BCM_CYGNUS_AUDIOPLL_CH1 2
+#define BCM_CYGNUS_AUDIOPLL_CH2 3
+
#endif /* _CLOCK_BCM_CYGNUS_H */
--
1.9.1

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