[PATCH 01/17] clk: renesas: rzv2h-cpg: Add support for DSI clocks

Prabhakar
2025-03-30T21:08:01Z

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Add support for PLLDSI and PLLDSI divider clocks.

The `renesas-rzv2h-dsi.h` header file is added to share the PLL divider
algorithm between the CPG and DSI drivers.

Co-developed-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
drivers/clk/renesas/rzv2h-cpg.c | 284 ++++++++++++++++++++++++++
drivers/clk/renesas/rzv2h-cpg.h | 14 ++
include/linux/clk/renesas-rzv2h-dsi.h | 207 +++++++++++++++++++
3 files changed, 505 insertions(+)
create mode 100644 include/linux/clk/renesas-rzv2h-dsi.h

diff --git a/drivers/clk/renesas/rzv2h-cpg.c b/drivers/clk/renesas/rzv2h-cpg.c
index e6a3c673879f..6ac21c379267 100644
--- a/drivers/clk/renesas/rzv2h-cpg.c
+++ b/drivers/clk/renesas/rzv2h-cpg.c
@@ -14,9 +14,13 @@
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
+#include <linux/clk/renesas-rzv2h-dsi.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/iopoll.h>
+#include <linux/math.h>
+#include <linux/math64.h>
+#include <linux/minmax.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/of.h>
@@ -26,6 +30,7 @@
#include <linux/refcount.h>
#include <linux/reset-controller.h>
#include <linux/string_choices.h>
+#include <linux/units.h>

#include <dt-bindings/clock/renesas-cpg-mssr.h>

@@ -48,6 +53,7 @@
#define CPG_PLL_STBY(x) ((x))
#define CPG_PLL_STBY_RESETB BIT(0)
#define CPG_PLL_STBY_RESETB_WEN BIT(16)
+#define CPG_PLL_STBY_SSCGEN_WEN BIT(18)
#define CPG_PLL_CLK1(x) ((x) + 0x004)
#define CPG_PLL_CLK1_KDIV(x) ((s16)FIELD_GET(GENMASK(31, 16), (x)))
#define CPG_PLL_CLK1_MDIV(x) FIELD_GET(GENMASK(15, 6), (x))
@@ -79,6 +85,8 @@
* @last_dt_core_clk: ID of the last Core Clock exported to DT
* @mstop_count: Array of mstop values
* @rcdev: Reset controller entity
+ * @dsi_limits: PLL DSI parameters limits
+ * @plldsi_div_parameters: PLL DSI and divider parameters configuration
*/
struct rzv2h_cpg_priv {
struct device *dev;
@@ -95,6 +103,9 @@ struct rzv2h_cpg_priv {
atomic_t *mstop_count;

struct reset_controller_dev rcdev;
+
+ const struct rzv2h_plldsi_div_limits *dsi_limits;
+ struct rzv2h_plldsi_parameters plldsi_div_parameters;
};

#define rcdev_to_priv(x) container_of(x, struct rzv2h_cpg_priv, rcdev)
@@ -148,6 +159,24 @@ struct ddiv_clk {

#define to_ddiv_clock(_div) container_of(_div, struct ddiv_clk, div)

+/**
+ * struct rzv2h_plldsi_div_clk - PLL DSI DDIV clock
+ *
+ * @dtable: divider table
+ * @priv: CPG private data
+ * @hw: divider clk
+ * @ddiv: divider configuration
+ */
+struct rzv2h_plldsi_div_clk {
+ const struct clk_div_table *dtable;
+ struct rzv2h_cpg_priv *priv;
+ struct clk_hw hw;
+ struct ddiv ddiv;
+};
+
+#define to_plldsi_div_clk(_hw) \
+ container_of(_hw, struct rzv2h_plldsi_div_clk, hw)
+
static int rzv2h_cpg_pll_clk_is_enabled(struct clk_hw *hw)
{
struct pll_clk *pll_clk = to_pll(hw);
@@ -196,6 +225,253 @@ static int rzv2h_cpg_pll_clk_enable(struct clk_hw *hw)
return ret;
}

+static unsigned long rzv2h_cpg_plldsi_div_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct rzv2h_plldsi_div_clk *dsi_div = to_plldsi_div_clk(hw);
+ struct rzv2h_cpg_priv *priv = dsi_div->priv;
+ struct ddiv ddiv = dsi_div->ddiv;
+ u32 div;
+
+ div = readl(priv->base + ddiv.offset);
+ div >>= ddiv.shift;
+ div &= ((2 << ddiv.width) - 1);
+
+ div = dsi_div->dtable[div].div;
+
+ return DIV_ROUND_CLOSEST_ULL(parent_rate, div);
+}
+
+static int rzv2h_cpg_plldsi_div_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ struct rzv2h_plldsi_div_clk *dsi_div = to_plldsi_div_clk(hw);
+ struct rzv2h_cpg_priv *priv = dsi_div->priv;
+ struct rzv2h_plldsi_parameters *dsi_dividers = &priv->plldsi_div_parameters;
+ unsigned long long rate_mhz;
+
+ /*
+ * Adjust the requested clock rate (`req->rate`) to ensure it falls within
+ * the supported range of 5.44 MHz to 187.5 MHz.
+ */
+ req->rate = clamp(req->rate, 5440000UL, 187500000UL);
+
+ rate_mhz = req->rate * MILLI * 1ULL;
+ if (rate_mhz == dsi_dividers->error_mhz + dsi_dividers->freq_mhz)
+ goto exit_determine_rate;
+
+ if (!rzv2h_dsi_get_pll_parameters_values(priv->dsi_limits,
+ dsi_dividers, rate_mhz)) {
+ dev_err(priv->dev,
+ "failed to determine rate for req->rate: %lu\n",
+ req->rate);
+ return -EINVAL;
+ }
+
+exit_determine_rate:
+ req->best_parent_rate = req->rate * dsi_dividers->csdiv;
+
+ return 0;
+};
+
+static int rzv2h_cpg_plldsi_div_set_rate(struct clk_hw *hw,
+ unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct rzv2h_plldsi_div_clk *dsi_div = to_plldsi_div_clk(hw);
+ struct rzv2h_cpg_priv *priv = dsi_div->priv;
+ struct rzv2h_plldsi_parameters *dsi_dividers = &priv->plldsi_div_parameters;
+ struct ddiv ddiv = dsi_div->ddiv;
+ const struct clk_div_table *clkt;
+ u32 reg, shift, div;
+
+ div = dsi_dividers->csdiv;
+ for (clkt = dsi_div->dtable; clkt->div; clkt++) {
+ if (clkt->div == div)
+ break;
+ }
+
+ if (!clkt->div && !clkt->val)
+ return -EINVAL;
+
+ shift = ddiv.shift;
+ reg = readl(priv->base + ddiv.offset);
+ reg &= ~(GENMASK(shift + ddiv.width, shift));
+
+ writel(reg | (clkt->val << shift) |
+ DDIV_DIVCTL_WEN(shift), priv->base + ddiv.offset);
+
+ return 0;
+};
+
+static const struct clk_ops rzv2h_cpg_plldsi_div_ops = {
+ .recalc_rate = rzv2h_cpg_plldsi_div_recalc_rate,
+ .determine_rate = rzv2h_cpg_plldsi_div_determine_rate,
+ .set_rate = rzv2h_cpg_plldsi_div_set_rate,
+};
+
+static struct clk * __init
+rzv2h_cpg_plldsi_div_clk_register(const struct cpg_core_clk *core,
+ struct rzv2h_cpg_priv *priv)
+{
+ struct rzv2h_plldsi_div_clk *clk_hw_data;
+ struct clk **clks = priv->clks;
+ struct clk_init_data init;
+ const struct clk *parent;
+ const char *parent_name;
+ struct clk_hw *clk_hw;
+ int ret;
+
+ parent = clks[core->parent];
+ if (IS_ERR(parent))
+ return ERR_CAST(parent);
+
+ clk_hw_data = devm_kzalloc(priv->dev, sizeof(*clk_hw_data), GFP_KERNEL);
+ if (!clk_hw_data)
+ return ERR_PTR(-ENOMEM);
+
+ clk_hw_data->priv = priv;
+ clk_hw_data->ddiv = core->cfg.ddiv;
+ clk_hw_data->dtable = core->dtable;
+
+ parent_name = __clk_get_name(parent);
+ init.name = core->name;
+ init.ops = &rzv2h_cpg_plldsi_div_ops;
+ init.flags = core->flag;
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+
+ clk_hw = &clk_hw_data->hw;
+ clk_hw->init = &init;
+
+ ret = devm_clk_hw_register(priv->dev, clk_hw);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return clk_hw->clk;
+}
+
+static long rzv2h_cpg_plldsi_round_rate(struct clk_hw *hw,
+ unsigned long rate,
+ unsigned long *parent_rate)
+{
+ return clamp(rate, 25000000UL, 375000000UL);
+}
+
+static unsigned long rzv2h_cpg_plldsi_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct pll_clk *pll_clk = to_pll(hw);
+ struct rzv2h_cpg_priv *priv = pll_clk->priv;
+ unsigned int val1, val2;
+ u64 rate;
+
+ val1 = readl(priv->base + CPG_PLL_CLK1(pll_clk->pll.offset));
+ val2 = readl(priv->base + CPG_PLL_CLK2(pll_clk->pll.offset));
+
+ rate = mul_u64_u32_shr(parent_rate, (CPG_PLL_CLK1_MDIV(val1) << 16) +
+ CPG_PLL_CLK1_KDIV(val1), 16 + CPG_PLL_CLK2_SDIV(val2));
+
+ return DIV_ROUND_CLOSEST_ULL(rate, CPG_PLL_CLK1_PDIV(val1));
+}
+
+static int rzv2h_cpg_plldsi_set_rate(struct clk_hw *hw,
+ unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct pll_clk *pll_clk = to_pll(hw);
+ struct rzv2h_cpg_priv *priv = pll_clk->priv;
+ struct rzv2h_plldsi_parameters *dsi_dividers;
+ struct pll pll = pll_clk->pll;
+ u16 offset = pll.offset;
+ u32 val;
+ int ret;
+
+ /* Put PLL into standby mode */
+ writel(CPG_PLL_STBY_RESETB_WEN, priv->base + CPG_PLL_STBY(offset));
+ ret = readl_poll_timeout_atomic(priv->base + CPG_PLL_MON(offset),
+ val, !(val & CPG_PLL_MON_LOCK),
+ 100, 2000);
+ if (ret) {
+ dev_err(priv->dev, "Failed to put PLLDSI into standby mode");
+ return ret;
+ }
+
+ dsi_dividers = &priv->plldsi_div_parameters;
+ /* Output clock setting 1 */
+ writel((dsi_dividers->k << 16) | (dsi_dividers->m << 6) | (dsi_dividers->p),
+ priv->base + CPG_PLL_CLK1(offset));
+
+ /* Output clock setting 2 */
+ val = readl(priv->base + CPG_PLL_CLK2(offset));
+ writel((val & ~GENMASK(2, 0)) | dsi_dividers->s,
+ priv->base + CPG_PLL_CLK2(offset));
+
+ /* Put PLL to normal mode */
+ writel(CPG_PLL_STBY_RESETB_WEN | CPG_PLL_STBY_RESETB,
+ priv->base + CPG_PLL_STBY(offset));
+
+ /* PLL normal mode transition, output clock stability check */
+ ret = readl_poll_timeout_atomic(priv->base + CPG_PLL_MON(offset),
+ val, (val & CPG_PLL_MON_LOCK),
+ 100, 2000);
+ if (ret) {
+ dev_err(priv->dev, "Failed to put PLLDSI into normal mode");
+ return ret;
+ }
+
+ return 0;
+};
+
+static const struct clk_ops rzv2h_cpg_plldsi_ops = {
+ .recalc_rate = rzv2h_cpg_plldsi_clk_recalc_rate,
+ .round_rate = rzv2h_cpg_plldsi_round_rate,
+ .set_rate = rzv2h_cpg_plldsi_set_rate,
+};
+
+static struct clk * __init
+rzv2h_cpg_plldsi_clk_register(const struct cpg_core_clk *core,
+ struct rzv2h_cpg_priv *priv)
+{
+ void __iomem *base = priv->base;
+ struct device *dev = priv->dev;
+ struct clk_init_data init;
+ const struct clk *parent;
+ const char *parent_name;
+ struct pll_clk *pll_clk;
+ int ret;
+
+ parent = priv->clks[core->parent];
+ if (IS_ERR(parent))
+ return ERR_CAST(parent);
+
+ pll_clk = devm_kzalloc(dev, sizeof(*pll_clk), GFP_KERNEL);
+ if (!pll_clk)
+ return ERR_PTR(-ENOMEM);
+
+ parent_name = __clk_get_name(parent);
+ init.name = core->name;
+ init.ops = &rzv2h_cpg_plldsi_ops;
+ init.flags = 0;
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+
+ pll_clk->hw.init = &init;
+ pll_clk->pll = core->cfg.pll;
+ pll_clk->base = base;
+ pll_clk->priv = priv;
+
+ /* Disable SSC and turn on PLL clock when init */
+ writel(CPG_PLL_STBY_RESETB_WEN | CPG_PLL_STBY_RESETB |
+ CPG_PLL_STBY_SSCGEN_WEN, base + CPG_PLL_STBY(pll_clk->pll.offset));
+
+ ret = devm_clk_hw_register(dev, &pll_clk->hw);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return pll_clk->hw.clk;
+}
+
static unsigned long rzv2h_cpg_pll_clk_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
@@ -508,6 +784,12 @@ rzv2h_cpg_register_core_clk(const struct cpg_core_clk *core,
case CLK_TYPE_SMUX:
clk = rzv2h_cpg_mux_clk_register(core, priv);
break;
+ case CLK_TYPE_PLLDSI:
+ clk = rzv2h_cpg_plldsi_clk_register(core, priv);
+ break;
+ case CLK_TYPE_PLLDSI_DIV:
+ clk = rzv2h_cpg_plldsi_div_clk_register(core, priv);
+ break;
default:
goto fail;
}
@@ -1047,6 +1329,8 @@ static int __init rzv2h_cpg_probe(struct platform_device *pdev)
priv->last_dt_core_clk = info->last_dt_core_clk;
priv->num_resets = info->num_resets;

+ priv->dsi_limits = info->plldsi_limits;
+
for (i = 0; i < nclks; i++)
clks[i] = ERR_PTR(-ENOENT);

diff --git a/drivers/clk/renesas/rzv2h-cpg.h b/drivers/clk/renesas/rzv2h-cpg.h
index 2250436c4c24..c60f9ff49439 100644
--- a/drivers/clk/renesas/rzv2h-cpg.h
+++ b/drivers/clk/renesas/rzv2h-cpg.h
@@ -88,6 +88,7 @@ struct smuxed {
#define CPG_CDDIV3 (0x40C)
#define CPG_CDDIV4 (0x410)
#define CPG_CSDIV0 (0x500)
+#define CPG_CSDIV1 (0x504)

#define CDDIV0_DIVCTL1 DDIV_PACK(CPG_CDDIV0, 4, 3, 1)
#define CDDIV0_DIVCTL2 DDIV_PACK(CPG_CDDIV0, 8, 3, 2)
@@ -151,6 +152,8 @@ enum clk_types {
CLK_TYPE_PLL,
CLK_TYPE_DDIV, /* Dynamic Switching Divider */
CLK_TYPE_SMUX, /* Static Mux */
+ CLK_TYPE_PLLDSI, /* PLLDSI */
+ CLK_TYPE_PLLDSI_DIV, /* PLLDSI divider */
};

#define DEF_TYPE(_name, _id, _type...) \
@@ -178,6 +181,14 @@ enum clk_types {
.num_parents = ARRAY_SIZE(_parent_names), \
.flag = CLK_SET_RATE_PARENT, \
.mux_flags = CLK_MUX_HIWORD_MASK)
+#define DEF_PLLDSI(_name, _id, _parent, _pll_packed) \
+ DEF_TYPE(_name, _id, CLK_TYPE_PLLDSI, .parent = _parent, .cfg.pll = _pll_packed)
+#define DEF_PLLDSI_DIV(_name, _id, _parent, _ddiv_packed, _dtable) \
+ DEF_TYPE(_name, _id, CLK_TYPE_PLLDSI_DIV, \
+ .cfg.ddiv = _ddiv_packed, \
+ .dtable = _dtable, \
+ .parent = _parent, \
+ .flag = CLK_SET_RATE_PARENT)

/**
* struct rzv2h_mod_clk - Module Clocks definitions
@@ -289,6 +300,7 @@ struct rzv2h_reset {
*
* @num_mstop_bits: Maximum number of MSTOP bits supported, equivalent to the
* number of CPG_BUS_m_MSTOP registers multiplied by 16.
+ * @plldsi_limits: PLL DSI parameters limits
*/
struct rzv2h_cpg_info {
/* Core Clocks */
@@ -307,6 +319,8 @@ struct rzv2h_cpg_info {
unsigned int num_resets;

unsigned int num_mstop_bits;
+
+ const struct rzv2h_plldsi_div_limits *plldsi_limits;
};

extern const struct rzv2h_cpg_info r9a09g047_cpg_info;
diff --git a/include/linux/clk/renesas-rzv2h-dsi.h b/include/linux/clk/renesas-rzv2h-dsi.h
new file mode 100644
index 000000000000..ee8bae8b7375
--- /dev/null
+++ b/include/linux/clk/renesas-rzv2h-dsi.h
@@ -0,0 +1,207 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Renesas RZ/V2H(P) DSI CPG helper
+ *
+ * Copyright (C) 2025 Renesas Electronics Corp.
+ */
+
+#include <linux/limits.h>
+#include <linux/math.h>
+#include <linux/math64.h>
+#include <linux/units.h>
+
+#define OSC_CLK_IN_MEGA (24 * MEGA)
+
+struct rzv2h_plldsi_div_limits {
+ struct {
+ u64 min;
+ u64 max;
+ } fvco;
+
+ struct {
+ u16 min;
+ u16 max;
+ } m;
+
+ struct {
+ u8 min;
+ u8 max;
+ } p;
+
+ struct {
+ u8 min;
+ u8 max;
+ } s;
+
+ struct {
+ s16 min;
+ s16 max;
+ } k;
+
+ struct {
+ u8 min;
+ u8 max;
+ } csdiv;
+};
+
+struct rzv2h_plldsi_parameters {
+ u64 freq_mhz;
+ s64 error_mhz;
+ u16 m;
+ s16 k;
+ u8 csdiv;
+ u8 p;
+ u8 s;
+};
+
+#define RZV2H_CPG_PLL_DSI_LIMITS(name) \
+ static const struct rzv2h_plldsi_div_limits (name) = { \
+ .m = { .min = 64, .max = 533 }, \
+ .p = { .min = 1, .max = 4 }, \
+ .s = { .min = 0, .max = 6 }, \
+ .k = { .min = -32768, .max = 32767 }, \
+ .csdiv = { .min = 2, .max = 32 }, \
+ .fvco = { .min = 1600 * MEGA, .max = 3200 * MEGA } \
+ } \
+
+/**
+ * rzv2h_dsi_get_pll_parameters_values - Finds the best combination of PLL parameters
+ * and divider value for a given frequency.
+ *
+ * @limits: Pointer to the structure containing the limits for the PLL parameters and
+ * divider values
+ * @pars: Pointer to the structure where the best calculated PLL parameters and divider
+ * values will be stored
+ * @freq: Target output frequency (in mHz)
+ *
+ * This function calculates the best set of PLL parameters (M, K, P, S) and divider
+ * value (CSDIV) to achieve the desired frequency.
+ * There is no direct formula to calculate the PLL parameters and the divider value,
+ * as it's an open system of equations, therefore this function uses an iterative
+ * approach to determine the best solution. The best solution is one that minimizes
+ * the error (desired frequency - actual frequency).
+ *
+ * Return: true if a valid set of divider values is found, false otherwise.
+ */
+static __maybe_unused bool
+rzv2h_dsi_get_pll_parameters_values(const struct rzv2h_plldsi_div_limits *limits,
+ struct rzv2h_plldsi_parameters *pars,
+ u64 freq_mhz)
+{
+ struct rzv2h_plldsi_parameters p, best;
+
+ /* Initialize best error to maximum possible value */
+ best.error_mhz = S64_MAX;
+
+ for (p.csdiv = limits->csdiv.min; p.csdiv <= limits->csdiv.max; p.csdiv += 2) {
+ for (p.p = limits->p.min; p.p <= limits->p.max; p.p++) {
+ u32 fref = OSC_CLK_IN_MEGA / p.p;
+
+ for (p.s = limits->s.min; p.s <= limits->s.max; p.s++) {
+ u16 two_pow_s = 1 << p.s;
+ u16 divider = two_pow_s * p.csdiv;
+
+ for (p.m = limits->m.min; p.m <= limits->m.max; p.m++) {
+ u64 output_m, output_k_range;
+ s64 pll_k, output_k;
+ u64 fvco, output;
+
+ /*
+ * The frequency generated by the combination of the
+ * PLL + divider is calculated as follows:
+ *
+ * Freq = Ffout / csdiv
+ *
+ * With:
+ * Ffout = Ffvco / 2^(pll_s)
+ * Ffvco = (pll_m + (pll_k / 65536)) * Ffref
+ * Ffref = 24MHz / pll_p
+ *
+ * Freq can also be rewritten as:
+ * Freq = Ffvco / (2^(pll_s) * csdiv))
+ * = Ffvco / divider
+ * = (pll_m * Ffref) / divider + ((pll_k / 65536) * Ffref) / divider
+ *      = output_m + output_k
+ *
+ * Every parameter has been determined at this point, but pll_k.
+ * Considering that:
+ * -32768 <= pll_k <= 32767
+ * Then:
+ * -0.5 <= (pll_k / 65536) < 0.5
+ * Therefore:
+ * -Ffref / (2 * divider) <= output_k < Ffref / (2 * divider)
+ */
+
+ /* Compute output M component (in mHz) */
+ output_m = DIV_ROUND_CLOSEST_ULL(p.m * fref * 1000ULL,
+ divider);
+ /* Compute range for output K (in mHz) */
+ output_k_range = DIV_ROUND_CLOSEST_ULL(fref * 1000ULL,
+ divider * 2);
+ /*
+ * No point in continuing if we can't achieve the
+ * desired frequency
+ */
+ if (freq_mhz < (output_m - output_k_range) ||
+ freq_mhz >= (output_m + output_k_range))
+ continue;
+
+ /*
+ * Compute the K component
+ *
+ * Since:
+ * Freq = output_m + output_k
+ * Then:
+ * output_k = Freq - output_m
+ * = ((pll_k / 65536) * Ffref) / divider
+ * Therefore:
+ * pll_k = (output_k * 65536 * divider) / Ffref
+ */
+ output_k = freq_mhz - output_m;
+ pll_k = div64_s64(output_k * 65536ULL * divider, fref);
+ pll_k = DIV_S64_ROUND_CLOSEST(pll_k, 1000);
+
+ /* Validate K value within allowed limits */
+ if (pll_k < limits->k.min || pll_k > limits->k.max)
+ continue;
+
+ p.k = pll_k;
+
+ /* Compute (Ffvco * 65536) */
+ fvco = ((p.m * 65536ULL) + p.k) * fref;
+ if ((fvco < (limits->fvco.min * 65536ULL)) ||
+ (fvco > (limits->fvco.max * 65536ULL)))
+ continue;
+
+ /* PLL_M component of (output * 65536 * PLL_P) */
+ output = p.m * 65536ULL * OSC_CLK_IN_MEGA;
+ /* PLL_K component of (output * 65536 * PLL_P) */
+ output += p.k * OSC_CLK_IN_MEGA;
+ /* Make it in mHz */
+ output *= 1000ULL;
+ output /= 65536ULL * p.p * divider;
+
+ p.error_mhz = freq_mhz - output;
+ p.freq_mhz = output;
+
+ /* If an exact match is found, return immediately */
+ if (p.error_mhz == 0) {
+ *pars = p;
+ return true;
+ }
+
+ /* Update best match if error is smaller */
+ if (abs(best.error_mhz) > abs(p.error_mhz))
+ best = p;
+ }
+ }
+ }
+ }
+
+ /* If no valid parameters were found, return false */
+ if (best.error_mhz == S64_MAX)
+ return false;
+
+ *pars = best;
+ return true;
+}
--
2.49.0