[PATCH RESEND v1 3/7] clk: microchip: mpfs: split MSSPLL in two

Conor Dooley
2023-12-08T17:13:06Z

From: Conor Dooley <conor.dooley@microchip.com>

The MSSPLL is really two stages - there's the PLL itself and 4 outputs,
each with their own divider. The current driver models this as a single
entity, outputting a single clock, used for both the CPU and AHB/AXI
buses. The other 3 outputs are used for the eMMC, "user crypto" and CAN
controller. Split the MSSPLL in two, as a precursor to adding support
for the other 3 outputs, with the PLL itself as one "hw" clock and the
output divider stage as another.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
---
drivers/clk/microchip/clk-mpfs.c | 188 ++++++++++++++++++++-----------
1 file changed, 123 insertions(+), 65 deletions(-)

diff --git a/drivers/clk/microchip/clk-mpfs.c b/drivers/clk/microchip/clk-mpfs.c
index c8ffa755b58d..b05bdab10cdc 100644
--- a/drivers/clk/microchip/clk-mpfs.c
+++ b/drivers/clk/microchip/clk-mpfs.c
@@ -30,6 +30,13 @@
#define MSSPLL_POSTDIV_WIDTH 0x07u
#define MSSPLL_FIXED_DIV 4u

+/*
+ * This clock ID is defined here, rather than the binding headers, as it is an
+ * internal clock only, and therefore has no consumers in other peripheral
+ * blocks.
+ */
+#define CLK_MSSPLL_INTERNAL 38u
+
struct mpfs_clock_data {
struct device *dev;
void __iomem *base;
@@ -39,17 +46,27 @@ struct mpfs_clock_data {

struct mpfs_msspll_hw_clock {
void __iomem *base;
+ struct clk_hw hw;
+ struct clk_init_data init;
unsigned int id;
u32 reg_offset;
u32 shift;
u32 width;
u32 flags;
- struct clk_hw hw;
- struct clk_init_data init;
};

#define to_mpfs_msspll_clk(_hw) container_of(_hw, struct mpfs_msspll_hw_clock, hw)

+struct mpfs_msspll_out_hw_clock {
+ void __iomem *base;
+ struct clk_hw hw;
+ struct clk_init_data init;
+ unsigned int id;
+ u32 flags;
+};
+
+#define to_mpfs_msspll_out_clk(_hw) container_of(_hw, struct mpfs_msspll_out_hw_clock, hw)
+
struct mpfs_cfg_hw_clock {
struct clk_divider cfg;
struct clk_init_data init;
@@ -93,93 +110,40 @@ static const struct clk_div_table mpfs_div_rtcref_table[] = {
{ 0, 0 }
};

+/*
+ * MSS PLL internal clock
+ */
+
static unsigned long mpfs_clk_msspll_recalc_rate(struct clk_hw *hw, unsigned long prate)
-{
- struct mpfs_msspll_hw_clock *msspll_hw = to_mpfs_msspll_clk(hw);
- void __iomem *mult_addr = msspll_hw->base + msspll_hw->reg_offset;
- void __iomem *ref_div_addr = msspll_hw->base + REG_MSSPLL_REF_CR;
- void __iomem *postdiv_addr = msspll_hw->base + REG_MSSPLL_POSTDIV_CR;
- u32 mult, ref_div, postdiv;
-
- mult = readl_relaxed(mult_addr) >> MSSPLL_FBDIV_SHIFT;
- mult &= clk_div_mask(MSSPLL_FBDIV_WIDTH);
- ref_div = readl_relaxed(ref_div_addr) >> MSSPLL_REFDIV_SHIFT;
- ref_div &= clk_div_mask(MSSPLL_REFDIV_WIDTH);
- postdiv = readl_relaxed(postdiv_addr) >> MSSPLL_POSTDIV_SHIFT;
- postdiv &= clk_div_mask(MSSPLL_POSTDIV_WIDTH);
-
- return prate * mult / (ref_div * MSSPLL_FIXED_DIV * postdiv);
-}
-
-static long mpfs_clk_msspll_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *prate)
{
struct mpfs_msspll_hw_clock *msspll_hw = to_mpfs_msspll_clk(hw);
void __iomem *mult_addr = msspll_hw->base + msspll_hw->reg_offset;
void __iomem *ref_div_addr = msspll_hw->base + REG_MSSPLL_REF_CR;
u32 mult, ref_div;
- unsigned long rate_before_ctrl;

mult = readl_relaxed(mult_addr) >> MSSPLL_FBDIV_SHIFT;
mult &= clk_div_mask(MSSPLL_FBDIV_WIDTH);
ref_div = readl_relaxed(ref_div_addr) >> MSSPLL_REFDIV_SHIFT;
ref_div &= clk_div_mask(MSSPLL_REFDIV_WIDTH);

- rate_before_ctrl = rate * (ref_div * MSSPLL_FIXED_DIV) / mult;
-
- return divider_round_rate(hw, rate_before_ctrl, prate, NULL, MSSPLL_POSTDIV_WIDTH,
- msspll_hw->flags);
-}
-
-static int mpfs_clk_msspll_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long prate)
-{
- struct mpfs_msspll_hw_clock *msspll_hw = to_mpfs_msspll_clk(hw);
- void __iomem *mult_addr = msspll_hw->base + msspll_hw->reg_offset;
- void __iomem *ref_div_addr = msspll_hw->base + REG_MSSPLL_REF_CR;
- void __iomem *postdiv_addr = msspll_hw->base + REG_MSSPLL_POSTDIV_CR;
- u32 mult, ref_div, postdiv;
- int divider_setting;
- unsigned long rate_before_ctrl, flags;
-
- mult = readl_relaxed(mult_addr) >> MSSPLL_FBDIV_SHIFT;
- mult &= clk_div_mask(MSSPLL_FBDIV_WIDTH);
- ref_div = readl_relaxed(ref_div_addr) >> MSSPLL_REFDIV_SHIFT;
- ref_div &= clk_div_mask(MSSPLL_REFDIV_WIDTH);
-
- rate_before_ctrl = rate * (ref_div * MSSPLL_FIXED_DIV) / mult;
- divider_setting = divider_get_val(rate_before_ctrl, prate, NULL, MSSPLL_POSTDIV_WIDTH,
- msspll_hw->flags);
-
- if (divider_setting < 0)
- return divider_setting;
-
- spin_lock_irqsave(&mpfs_clk_lock, flags);
-
- postdiv = readl_relaxed(postdiv_addr);
- postdiv &= ~(clk_div_mask(MSSPLL_POSTDIV_WIDTH) << MSSPLL_POSTDIV_SHIFT);
- writel_relaxed(postdiv, postdiv_addr);
-
- spin_unlock_irqrestore(&mpfs_clk_lock, flags);
-
- return 0;
+ return prate * mult / (ref_div * MSSPLL_FIXED_DIV);
}

static const struct clk_ops mpfs_clk_msspll_ops = {
.recalc_rate = mpfs_clk_msspll_recalc_rate,
- .round_rate = mpfs_clk_msspll_round_rate,
- .set_rate = mpfs_clk_msspll_set_rate,
};

#define CLK_PLL(_id, _name, _parent, _shift, _width, _flags, _offset) { \
.id = _id, \
+ .flags = _flags, \
.shift = _shift, \
.width = _width, \
.reg_offset = _offset, \
- .flags = _flags, \
.hw.init = CLK_HW_INIT_PARENTS_DATA(_name, _parent, &mpfs_clk_msspll_ops, 0), \
}

static struct mpfs_msspll_hw_clock mpfs_msspll_clks[] = {
- CLK_PLL(CLK_MSSPLL, "clk_msspll", mpfs_ext_ref, MSSPLL_FBDIV_SHIFT,
+ CLK_PLL(CLK_MSSPLL_INTERNAL, "clk_msspll_internal", mpfs_ext_ref, MSSPLL_FBDIV_SHIFT,
MSSPLL_FBDIV_WIDTH, 0, REG_MSSPLL_SSCG_2_CR),
};

@@ -196,7 +160,7 @@ static int mpfs_clk_register_mssplls(struct device *dev, struct mpfs_msspll_hw_c
ret = devm_clk_hw_register(dev, &msspll_hw->hw);
if (ret)
return dev_err_probe(dev, ret, "failed to register msspll id: %d\n",
- CLK_MSSPLL);
+ CLK_MSSPLL_INTERNAL);

data->hw_data.hws[msspll_hw->id] = &msspll_hw->hw;
}
@@ -204,6 +168,94 @@ static int mpfs_clk_register_mssplls(struct device *dev, struct mpfs_msspll_hw_c
return 0;
}

+/*
+ * MSS PLL output clocks
+ */
+
+static unsigned long mpfs_clk_msspll_out_recalc_rate(struct clk_hw *hw, unsigned long prate)
+{
+ struct mpfs_msspll_out_hw_clock *msspll_out_hw = to_mpfs_msspll_out_clk(hw);
+ void __iomem *postdiv_addr = msspll_out_hw->base + REG_MSSPLL_POSTDIV_CR;
+ u32 postdiv;
+
+ postdiv = readl_relaxed(postdiv_addr) >> MSSPLL_POSTDIV_SHIFT;
+ postdiv &= clk_div_mask(MSSPLL_POSTDIV_WIDTH);
+
+ return prate / postdiv;
+}
+
+static long mpfs_clk_msspll_out_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ struct mpfs_msspll_out_hw_clock *msspll_out_hw = to_mpfs_msspll_out_clk(hw);
+
+ return divider_round_rate(hw, rate, prate, NULL, MSSPLL_POSTDIV_WIDTH,
+ msspll_out_hw->flags);
+}
+
+static int mpfs_clk_msspll_out_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long prate)
+{
+ struct mpfs_msspll_out_hw_clock *msspll_out_hw = to_mpfs_msspll_out_clk(hw);
+ void __iomem *postdiv_addr = msspll_out_hw->base + REG_MSSPLL_POSTDIV_CR;
+ u32 postdiv;
+ int divider_setting;
+ unsigned long flags;
+
+ divider_setting = divider_get_val(rate, prate, NULL, MSSPLL_POSTDIV_WIDTH,
+ msspll_out_hw->flags);
+
+ if (divider_setting < 0)
+ return divider_setting;
+
+ spin_lock_irqsave(&mpfs_clk_lock, flags);
+
+ postdiv = readl_relaxed(postdiv_addr);
+ postdiv &= ~(clk_div_mask(MSSPLL_POSTDIV_WIDTH) << MSSPLL_POSTDIV_SHIFT);
+ writel_relaxed(postdiv, postdiv_addr);
+
+ spin_unlock_irqrestore(&mpfs_clk_lock, flags);
+
+ return 0;
+}
+
+static const struct clk_ops mpfs_clk_msspll_out_ops = {
+ .recalc_rate = mpfs_clk_msspll_out_recalc_rate,
+ .round_rate = mpfs_clk_msspll_out_round_rate,
+ .set_rate = mpfs_clk_msspll_out_set_rate,
+};
+
+#define CLK_PLL_OUT(_id, _name, _parent, _flags) { \
+ .id = _id, \
+ .flags = _flags, \
+ .hw.init = CLK_HW_INIT(_name, _parent, &mpfs_clk_msspll_out_ops, 0), \
+}
+
+static struct mpfs_msspll_out_hw_clock mpfs_msspll_out_clks[] = {
+ CLK_PLL_OUT(CLK_MSSPLL, "clk_msspll", "clk_msspll_internal", 0),
+};
+
+static int mpfs_clk_register_msspll_outs(struct device *dev,
+ struct mpfs_msspll_out_hw_clock *msspll_out_hws,
+ unsigned int num_clks, struct mpfs_clock_data *data)
+{
+ unsigned int i;
+ int ret;
+
+ for (i = 0; i < num_clks; i++) {
+ struct mpfs_msspll_out_hw_clock *msspll_out_hw = &msspll_out_hws[i];
+
+ msspll_out_hw->base = data->msspll_base;
+ ret = devm_clk_hw_register(dev, &msspll_out_hw->hw);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to register msspll out id: %d\n",
+ msspll_out_hw->id);
+
+ data->hw_data.hws[msspll_out_hw->id] = &msspll_out_hw->hw;
+ }
+
+ return 0;
+}
+
/*
* "CFG" clocks
*/
@@ -442,8 +494,8 @@ static int mpfs_clk_probe(struct platform_device *pdev)
int ret;

/* CLK_RESERVED is not part of clock arrays, so add 1 */
- num_clks = ARRAY_SIZE(mpfs_msspll_clks) + ARRAY_SIZE(mpfs_cfg_clks)
- + ARRAY_SIZE(mpfs_periph_clks) + 1;
+ num_clks = ARRAY_SIZE(mpfs_msspll_clks) + ARRAY_SIZE(mpfs_msspll_out_clks)
+ + ARRAY_SIZE(mpfs_cfg_clks) + ARRAY_SIZE(mpfs_periph_clks) + 1;

clk_data = devm_kzalloc(dev, struct_size(clk_data, hw_data.hws, num_clks), GFP_KERNEL);
if (!clk_data)
@@ -466,6 +518,12 @@ static int mpfs_clk_probe(struct platform_device *pdev)
if (ret)
return ret;

+ ret = mpfs_clk_register_msspll_outs(dev, mpfs_msspll_out_clks,
+ ARRAY_SIZE(mpfs_msspll_out_clks),
+ clk_data);
+ if (ret)
+ return ret;
+
ret = mpfs_clk_register_cfgs(dev, mpfs_cfg_clks, ARRAY_SIZE(mpfs_cfg_clks), clk_data);
if (ret)
return ret;
--
2.39.2