[PATCH v7 4/7] clk: starfive: Add StarFive JH7110 PLL clock driver

Xingyu Wu
2023-07-17T02:31:07Z

Add driver for the StarFive JH7110 PLL clock controller
and they work by reading and setting syscon registers.

Co-developed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Xingyu Wu <xingyu.wu@starfivetech.com>
---
MAINTAINERS | 6 +
drivers/clk/starfive/Kconfig | 8 +
drivers/clk/starfive/Makefile | 1 +
.../clk/starfive/clk-starfive-jh7110-pll.c | 507 ++++++++++++++++++
4 files changed, 522 insertions(+)
create mode 100644 drivers/clk/starfive/clk-starfive-jh7110-pll.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 44b4358c3c3a..2065829321b7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -20282,6 +20282,12 @@ S: Supported
F: Documentation/devicetree/bindings/mmc/starfive*
F: drivers/mmc/host/dw_mmc-starfive.c

+STARFIVE JH7110 PLL CLOCK DRIVER
+M: Xingyu Wu <xingyu.wu@starfivetech.com>
+S: Supported
+F: Documentation/devicetree/bindings/clock/starfive,jh7110-pll.yaml
+F: drivers/clk/starfive/clk-starfive-jh7110-pll.c
+
STARFIVE JH7110 SYSCON
M: William Qiu <william.qiu@starfivetech.com>
M: Xingyu Wu <xingyu.wu@starfivetech.com>
diff --git a/drivers/clk/starfive/Kconfig b/drivers/clk/starfive/Kconfig
index 5d2333106f13..5195f7be5213 100644
--- a/drivers/clk/starfive/Kconfig
+++ b/drivers/clk/starfive/Kconfig
@@ -21,6 +21,14 @@ config CLK_STARFIVE_JH7100_AUDIO
Say Y or M here to support the audio clocks on the StarFive JH7100
SoC.

+config CLK_STARFIVE_JH7110_PLL
+ bool "StarFive JH7110 PLL clock support"
+ depends on ARCH_STARFIVE || COMPILE_TEST
+ default ARCH_STARFIVE
+ help
+ Say yes here to support the PLL clock controller on the
+ StarFive JH7110 SoC.
+
config CLK_STARFIVE_JH7110_SYS
bool "StarFive JH7110 system clock support"
depends on ARCH_STARFIVE || COMPILE_TEST
diff --git a/drivers/clk/starfive/Makefile b/drivers/clk/starfive/Makefile
index f3df7d957b1e..b48e539e52b0 100644
--- a/drivers/clk/starfive/Makefile
+++ b/drivers/clk/starfive/Makefile
@@ -4,5 +4,6 @@ obj-$(CONFIG_CLK_STARFIVE_JH71X0) += clk-starfive-jh71x0.o
obj-$(CONFIG_CLK_STARFIVE_JH7100) += clk-starfive-jh7100.o
obj-$(CONFIG_CLK_STARFIVE_JH7100_AUDIO) += clk-starfive-jh7100-audio.o

+obj-$(CONFIG_CLK_STARFIVE_JH7110_PLL) += clk-starfive-jh7110-pll.o
obj-$(CONFIG_CLK_STARFIVE_JH7110_SYS) += clk-starfive-jh7110-sys.o
obj-$(CONFIG_CLK_STARFIVE_JH7110_AON) += clk-starfive-jh7110-aon.o
diff --git a/drivers/clk/starfive/clk-starfive-jh7110-pll.c b/drivers/clk/starfive/clk-starfive-jh7110-pll.c
new file mode 100644
index 000000000000..3598390e8fd0
--- /dev/null
+++ b/drivers/clk/starfive/clk-starfive-jh7110-pll.c
@@ -0,0 +1,507 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * StarFive JH7110 PLL Clock Generator Driver
+ *
+ * Copyright (C) 2023 StarFive Technology Co., Ltd.
+ * Copyright (C) 2023 Emil Renner Berthing <emil.renner.berthing@canonical.com>
+ *
+ * This driver is about to register JH7110 PLL clock generator and support ops.
+ * The JH7110 have three PLL clock, PLL0, PLL1 and PLL2.
+ * Each PLL clocks work in integer mode or fraction mode by some dividers,
+ * and the configuration registers and dividers are set in several syscon registers.
+ * The formula for calculating frequency is:
+ * Fvco = Fref * (NI + NF) / M / Q1
+ * Fref: OSC source clock rate
+ * NI: integer frequency dividing ratio of feedback divider, set by fbdiv[11:0].
+ * NF: fractional frequency dividing ratio, set by frac[23:0]. NF = frac[23:0] / 2^24 = 0 ~ 0.999.
+ * M: frequency dividing ratio of pre-divider, set by prediv[5:0].
+ * Q1: frequency dividing ratio of post divider, set by 2^postdiv1[1:0], eg. 1, 2, 4 or 8.
+ */
+
+#include <linux/bits.h>
+#include <linux/clk-provider.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <dt-bindings/clock/starfive,jh7110-crg.h>
+
+/* this driver expects a 24MHz input frequency from the oscillator */
+#define JH7110_PLL_OSC_RATE 24000000UL
+
+#define JH7110_PLL0_PD_OFFSET 0x18
+#define JH7110_PLL0_DACPD_SHIFT 24
+#define JH7110_PLL0_DACPD_MASK BIT(24)
+#define JH7110_PLL0_DSMPD_SHIFT 25
+#define JH7110_PLL0_DSMPD_MASK BIT(25)
+#define JH7110_PLL0_FBDIV_OFFSET 0x1c
+#define JH7110_PLL0_FBDIV_SHIFT 0
+#define JH7110_PLL0_FBDIV_MASK GENMASK(11, 0)
+#define JH7110_PLL0_FRAC_OFFSET 0x20
+#define JH7110_PLL0_PREDIV_OFFSET 0x24
+
+#define JH7110_PLL1_PD_OFFSET 0x24
+#define JH7110_PLL1_DACPD_SHIFT 15
+#define JH7110_PLL1_DACPD_MASK BIT(15)
+#define JH7110_PLL1_DSMPD_SHIFT 16
+#define JH7110_PLL1_DSMPD_MASK BIT(16)
+#define JH7110_PLL1_FBDIV_OFFSET 0x24
+#define JH7110_PLL1_FBDIV_SHIFT 17
+#define JH7110_PLL1_FBDIV_MASK GENMASK(28, 17)
+#define JH7110_PLL1_FRAC_OFFSET 0x28
+#define JH7110_PLL1_PREDIV_OFFSET 0x2c
+
+#define JH7110_PLL2_PD_OFFSET 0x2c
+#define JH7110_PLL2_DACPD_SHIFT 15
+#define JH7110_PLL2_DACPD_MASK BIT(15)
+#define JH7110_PLL2_DSMPD_SHIFT 16
+#define JH7110_PLL2_DSMPD_MASK BIT(16)
+#define JH7110_PLL2_FBDIV_OFFSET 0x2c
+#define JH7110_PLL2_FBDIV_SHIFT 17
+#define JH7110_PLL2_FBDIV_MASK GENMASK(28, 17)
+#define JH7110_PLL2_FRAC_OFFSET 0x30
+#define JH7110_PLL2_PREDIV_OFFSET 0x34
+
+#define JH7110_PLL_FRAC_SHIFT 0
+#define JH7110_PLL_FRAC_MASK GENMASK(23, 0)
+#define JH7110_PLL_POSTDIV1_SHIFT 28
+#define JH7110_PLL_POSTDIV1_MASK GENMASK(29, 28)
+#define JH7110_PLL_PREDIV_SHIFT 0
+#define JH7110_PLL_PREDIV_MASK GENMASK(5, 0)
+
+enum jh7110_pll_mode {
+ JH7110_PLL_MODE_FRACTION,
+ JH7110_PLL_MODE_INTEGER,
+};
+
+struct jh7110_pll_preset {
+ unsigned long freq;
+ u32 frac; /* frac value should be decimals multiplied by 2^24 */
+ unsigned fbdiv : 12; /* fbdiv value should be 8 to 4095 */
+ unsigned prediv : 6;
+ unsigned postdiv1 : 2;
+ unsigned mode : 1;
+};
+
+struct jh7110_pll_info {
+ char *name;
+ const struct jh7110_pll_preset *presets;
+ unsigned int npresets;
+ struct {
+ unsigned int pd;
+ unsigned int fbdiv;
+ unsigned int frac;
+ unsigned int prediv;
+ } offsets;
+ struct {
+ u32 dacpd;
+ u32 dsmpd;
+ u32 fbdiv;
+ } masks;
+ struct {
+ char dacpd;
+ char dsmpd;
+ char fbdiv;
+ } shifts;
+};
+
+#define _JH7110_PLL(_idx, _name, _presets) \
+ [_idx] = { \
+ .name = _name, \
+ .presets = _presets, \
+ .npresets = ARRAY_SIZE(_presets), \
+ .offsets = { \
+ .pd = JH7110_PLL##_idx##_PD_OFFSET, \
+ .fbdiv = JH7110_PLL##_idx##_FBDIV_OFFSET, \
+ .frac = JH7110_PLL##_idx##_FRAC_OFFSET, \
+ .prediv = JH7110_PLL##_idx##_PREDIV_OFFSET, \
+ }, \
+ .masks = { \
+ .dacpd = JH7110_PLL##_idx##_DACPD_MASK, \
+ .dsmpd = JH7110_PLL##_idx##_DSMPD_MASK, \
+ .fbdiv = JH7110_PLL##_idx##_FBDIV_MASK, \
+ }, \
+ .shifts = { \
+ .dacpd = JH7110_PLL##_idx##_DACPD_SHIFT, \
+ .dsmpd = JH7110_PLL##_idx##_DSMPD_SHIFT, \
+ .fbdiv = JH7110_PLL##_idx##_FBDIV_SHIFT, \
+ }, \
+ }
+#define JH7110_PLL(idx, name, presets) _JH7110_PLL(idx, name, presets)
+
+struct jh7110_pll_data {
+ struct clk_hw hw;
+ unsigned int idx;
+};
+
+struct jh7110_pll_priv {
+ struct device *dev;
+ struct regmap *regmap;
+ struct jh7110_pll_data pll[JH7110_PLLCLK_END];
+};
+
+struct jh7110_pll_regvals {
+ u32 dacpd;
+ u32 dsmpd;
+ u32 fbdiv;
+ u32 frac;
+ u32 postdiv1;
+ u32 prediv;
+};
+
+/*
+ * Because the pll frequency is relatively fixed,
+ * it cannot be set arbitrarily, so it needs a specific configuration.
+ * PLL0 frequency should be multiple of 125MHz (USB frequency).
+ */
+static const struct jh7110_pll_preset jh7110_pll0_presets[] = {
+ {
+ .freq = 375000000,
+ .fbdiv = 125,
+ .prediv = 8,
+ .postdiv1 = 0,
+ .mode = JH7110_PLL_MODE_INTEGER,
+ }, {
+ .freq = 500000000,
+ .fbdiv = 125,
+ .prediv = 6,
+ .postdiv1 = 0,
+ .mode = JH7110_PLL_MODE_INTEGER,
+ }, {
+ .freq = 625000000,
+ .fbdiv = 625,
+ .prediv = 24,
+ .postdiv1 = 0,
+ .mode = JH7110_PLL_MODE_INTEGER,
+ }, {
+ .freq = 750000000,
+ .fbdiv = 125,
+ .prediv = 4,
+ .postdiv1 = 0,
+ .mode = JH7110_PLL_MODE_INTEGER,
+ }, {
+ .freq = 875000000,
+ .fbdiv = 875,
+ .prediv = 24,
+ .postdiv1 = 0,
+ .mode = JH7110_PLL_MODE_INTEGER,
+ }, {
+ .freq = 1000000000,
+ .fbdiv = 125,
+ .prediv = 3,
+ .postdiv1 = 0,
+ .mode = JH7110_PLL_MODE_INTEGER,
+ }, {
+ .freq = 1250000000,
+ .fbdiv = 625,
+ .prediv = 12,
+ .postdiv1 = 0,
+ .mode = JH7110_PLL_MODE_INTEGER,
+ }, {
+ .freq = 1375000000,
+ .fbdiv = 1375,
+ .prediv = 24,
+ .postdiv1 = 0,
+ .mode = JH7110_PLL_MODE_INTEGER,
+ }, {
+ .freq = 1500000000,
+ .fbdiv = 125,
+ .prediv = 2,
+ .postdiv1 = 0,
+ .mode = JH7110_PLL_MODE_INTEGER,
+ },
+};
+
+static const struct jh7110_pll_preset jh7110_pll1_presets[] = {
+ {
+ .freq = 1066000000,
+ .fbdiv = 533,
+ .prediv = 12,
+ .postdiv1 = 0,
+ .mode = JH7110_PLL_MODE_INTEGER,
+ }, {
+ .freq = 1200000000,
+ .fbdiv = 50,
+ .prediv = 1,
+ .postdiv1 = 0,
+ .mode = JH7110_PLL_MODE_INTEGER,
+ }, {
+ .freq = 1400000000,
+ .fbdiv = 350,
+ .prediv = 6,
+ .postdiv1 = 0,
+ .mode = JH7110_PLL_MODE_INTEGER,
+ }, {
+ .freq = 1600000000,
+ .fbdiv = 200,
+ .prediv = 3,
+ .postdiv1 = 0,
+ .mode = JH7110_PLL_MODE_INTEGER,
+ },
+};
+
+static const struct jh7110_pll_preset jh7110_pll2_presets[] = {
+ {
+ .freq = 1188000000,
+ .fbdiv = 99,
+ .prediv = 2,
+ .postdiv1 = 0,
+ .mode = JH7110_PLL_MODE_INTEGER,
+ }, {
+ .freq = 1228800000,
+ .fbdiv = 256,
+ .prediv = 5,
+ .postdiv1 = 0,
+ .mode = JH7110_PLL_MODE_INTEGER,
+ },
+};
+
+static const struct jh7110_pll_info jh7110_plls[JH7110_PLLCLK_END] = {
+ JH7110_PLL(JH7110_PLLCLK_PLL0_OUT, "pll0_out", jh7110_pll0_presets),
+ JH7110_PLL(JH7110_PLLCLK_PLL1_OUT, "pll1_out", jh7110_pll1_presets),
+ JH7110_PLL(JH7110_PLLCLK_PLL2_OUT, "pll2_out", jh7110_pll2_presets),
+};
+
+static struct jh7110_pll_data *jh7110_pll_data_from(struct clk_hw *hw)
+{
+ return container_of(hw, struct jh7110_pll_data, hw);
+}
+
+static struct jh7110_pll_priv *jh7110_pll_priv_from(struct jh7110_pll_data *pll)
+{
+ return container_of(pll, struct jh7110_pll_priv, pll[pll->idx]);
+}
+
+static void jh7110_pll_regvals_get(struct regmap *regmap,
+ const struct jh7110_pll_info *info,
+ struct jh7110_pll_regvals *ret)
+{
+ u32 val;
+
+ regmap_read(regmap, info->offsets.pd, &val);
+ ret->dacpd = (val & info->masks.dacpd) >> info->shifts.dacpd;
+ ret->dsmpd = (val & info->masks.dsmpd) >> info->shifts.dsmpd;
+
+ regmap_read(regmap, info->offsets.fbdiv, &val);
+ ret->fbdiv = (val & info->masks.fbdiv) >> info->shifts.fbdiv;
+
+ regmap_read(regmap, info->offsets.frac, &val);
+ ret->frac = (val & JH7110_PLL_FRAC_MASK) >> JH7110_PLL_FRAC_SHIFT;
+ ret->postdiv1 = (val & JH7110_PLL_POSTDIV1_MASK) >> JH7110_PLL_POSTDIV1_SHIFT;
+
+ regmap_read(regmap, info->offsets.prediv, &val);
+ ret->prediv = (val & JH7110_PLL_PREDIV_MASK) >> JH7110_PLL_PREDIV_SHIFT;
+}
+
+static unsigned long jh7110_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
+{
+ struct jh7110_pll_data *pll = jh7110_pll_data_from(hw);
+ struct jh7110_pll_priv *priv = jh7110_pll_priv_from(pll);
+ struct jh7110_pll_regvals val;
+ unsigned long rate;
+
+ jh7110_pll_regvals_get(priv->regmap, &jh7110_plls[pll->idx], &val);
+
+ /*
+ * dacpd = dsmpd = 0: fraction mode
+ * dacpd = dsmpd = 1: integer mode, frac value ignored
+ *
+ * rate = parent * (fbdiv + frac/2^24) / prediv / 2^postdiv1
+ * = (parent * fbdiv + parent * frac / 2^24) / (prediv * 2^postdiv1)
+ */
+ if (val.dacpd == 0 && val.dsmpd == 0)
+ rate = parent_rate * val.frac / (1UL << 24);
+ else if (val.dacpd == 1 && val.dsmpd == 1)
+ rate = 0;
+ else
+ return 0;
+
+ rate += parent_rate * val.fbdiv;
+ rate /= val.prediv << val.postdiv1;
+
+ return rate;
+}
+
+static int jh7110_pll_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
+{
+ struct jh7110_pll_data *pll = jh7110_pll_data_from(hw);
+ const struct jh7110_pll_info *info = &jh7110_plls[pll->idx];
+ const struct jh7110_pll_preset *selected = &info->presets[0];
+ unsigned int idx;
+
+ /* if the parent rate doesn't match our expectations the presets won't work */
+ if (req->best_parent_rate != JH7110_PLL_OSC_RATE) {
+ req->rate = jh7110_pll_recalc_rate(hw, req->best_parent_rate);
+ return 0;
+ }
+
+ /* find highest rate lower or equal to the requested rate */
+ for (idx = 1; idx < info->npresets; idx++) {
+ const struct jh7110_pll_preset *val = &info->presets[idx];
+
+ if (req->rate < val->freq)
+ break;
+
+ selected = val;
+ }
+
+ req->rate = selected->freq;
+ return 0;
+}
+
+static int jh7110_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct jh7110_pll_data *pll = jh7110_pll_data_from(hw);
+ struct jh7110_pll_priv *priv = jh7110_pll_priv_from(pll);
+ const struct jh7110_pll_info *info = &jh7110_plls[pll->idx];
+ const struct jh7110_pll_preset *val;
+ unsigned int idx;
+
+ /* if the parent rate doesn't match our expectations the presets won't work */
+ if (parent_rate != JH7110_PLL_OSC_RATE)
+ return -EINVAL;
+
+ for (idx = 0, val = &info->presets[0]; idx < info->npresets; idx++, val++) {
+ if (val->freq == rate)
+ goto found;
+ }
+ return -EINVAL;
+
+found:
+ if (val->mode == JH7110_PLL_MODE_FRACTION)
+ regmap_update_bits(priv->regmap, info->offsets.frac, JH7110_PLL_FRAC_MASK,
+ val->frac << JH7110_PLL_FRAC_SHIFT);
+
+ regmap_update_bits(priv->regmap, info->offsets.pd, info->masks.dacpd,
+ (u32)val->mode << info->shifts.dacpd);
+ regmap_update_bits(priv->regmap, info->offsets.pd, info->masks.dsmpd,
+ (u32)val->mode << info->shifts.dsmpd);
+ regmap_update_bits(priv->regmap, info->offsets.prediv, JH7110_PLL_PREDIV_MASK,
+ (u32)val->prediv << JH7110_PLL_PREDIV_SHIFT);
+ regmap_update_bits(priv->regmap, info->offsets.fbdiv, info->masks.fbdiv,
+ val->fbdiv << info->shifts.fbdiv);
+ regmap_update_bits(priv->regmap, info->offsets.frac, JH7110_PLL_POSTDIV1_MASK,
+ (u32)val->postdiv1 << JH7110_PLL_POSTDIV1_SHIFT);
+
+ return 0;
+}
+
+#ifdef CONFIG_DEBUG_FS
+static int jh7110_pll_registers_read(struct seq_file *s, void *unused)
+{
+ struct jh7110_pll_data *pll = s->private;
+ struct jh7110_pll_priv *priv = jh7110_pll_priv_from(pll);
+ struct jh7110_pll_regvals val;
+
+ jh7110_pll_regvals_get(priv->regmap, &jh7110_plls[pll->idx], &val);
+
+ seq_printf(s, "fbdiv=%u\n"
+ "frac=%u\n"
+ "prediv=%u\n"
+ "postdiv1=%u\n"
+ "dacpd=%u\n"
+ "dsmpd=%u\n",
+ val.fbdiv, val.frac, val.prediv, val.postdiv1,
+ val.dacpd, val.dsmpd);
+
+ return 0;
+}
+
+static int jh7110_pll_registers_open(struct inode *inode, struct file *f)
+{
+ return single_open(f, jh7110_pll_registers_read, inode->i_private);
+}
+
+static const struct file_operations jh7110_pll_registers_ops = {
+ .owner = THIS_MODULE,
+ .open = jh7110_pll_registers_open,
+ .release = single_release,
+ .read = seq_read,
+ .llseek = seq_lseek
+};
+
+static void jh7110_pll_debug_init(struct clk_hw *hw, struct dentry *dentry)
+{
+ struct jh7110_pll_data *pll = jh7110_pll_data_from(hw);
+
+ debugfs_create_file("registers", 0400, dentry, pll,
+ &jh7110_pll_registers_ops);
+}
+#else
+#define jh7110_pll_debug_init NULL
+#endif
+
+static const struct clk_ops jh7110_pll_ops = {
+ .recalc_rate = jh7110_pll_recalc_rate,
+ .determine_rate = jh7110_pll_determine_rate,
+ .set_rate = jh7110_pll_set_rate,
+ .debug_init = jh7110_pll_debug_init,
+};
+
+static struct clk_hw *jh7110_pll_get(struct of_phandle_args *clkspec, void *data)
+{
+ struct jh7110_pll_priv *priv = data;
+ unsigned int idx = clkspec->args[0];
+
+ if (idx < JH7110_PLLCLK_END)
+ return &priv->pll[idx].hw;
+
+ return ERR_PTR(-EINVAL);
+}
+
+static int jh7110_pll_probe(struct platform_device *pdev)
+{
+ struct jh7110_pll_priv *priv;
+ unsigned int idx;
+ int ret;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->dev = &pdev->dev;
+ priv->regmap = syscon_node_to_regmap(priv->dev->of_node->parent);
+ if (IS_ERR(priv->regmap))
+ return PTR_ERR(priv->regmap);
+
+ for (idx = 0; idx < JH7110_PLLCLK_END; idx++) {
+ struct clk_parent_data parents = {
+ .index = 0,
+ };
+ struct clk_init_data init = {
+ .name = jh7110_plls[idx].name,
+ .ops = &jh7110_pll_ops,
+ .parent_data = &parents,
+ .num_parents = 1,
+ .flags = 0,
+ };
+ struct jh7110_pll_data *pll = &priv->pll[idx];
+
+ pll->hw.init = &init;
+ pll->idx = idx;
+
+ ret = devm_clk_hw_register(&pdev->dev, &pll->hw);
+ if (ret)
+ return ret;
+ }
+
+ return devm_of_clk_add_hw_provider(&pdev->dev, jh7110_pll_get, priv);
+}
+
+static const struct of_device_id jh7110_pll_match[] = {
+ { .compatible = "starfive,jh7110-pll" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, jh7110_pll_match);
+
+static struct platform_driver jh7110_pll_driver = {
+ .driver = {
+ .name = "clk-starfive-jh7110-pll",
+ .of_match_table = jh7110_pll_match,
+ },
+};
+builtin_platform_driver_probe(jh7110_pll_driver, jh7110_pll_probe);
--
2.25.1