by Sergio Paracuellos

[permalink] [raw]

Subject: Re: [PATCH v11 3/6] clk: ralink: add clock driver for mt7621 SoC

Hi,

On Fri, Apr 9, 2021 at 8:14 PM Stephen Boyd <[email protected]> wrote:
>
> Quoting Sergio Paracuellos (2021-03-08 21:22:23)
> > diff --git a/drivers/clk/ralink/Kconfig b/drivers/clk/ralink/Kconfig
> > new file mode 100644
> > index 000000000000..3e3f5cb9ad88
> > --- /dev/null
> > +++ b/drivers/clk/ralink/Kconfig
> > @@ -0,0 +1,15 @@
> > +# SPDX-License-Identifier: GPL-2.0-only
> > +#
> > +# MediaTek Mt7621 Clock Driver
> > +#
> > +menu "Clock driver for Mediatek mt7621 SoC"
> > + depends on SOC_MT7621 || COMPILE_TEST
>
> Do we need a menu and a config that says the same thing? Maybe the menu
> can be dropped?

Ok, I will drop the menu from this Kconfig.

>
> > +
> > +config CLK_MT7621
> > + bool "Clock driver for MediaTek MT7621"
> > + depends on SOC_MT7621 || COMPILE_TEST
> > + default SOC_MT7621
> > + select MFD_SYSCON
> > + help
> > + This driver supports MediaTek MT7621 basic clocks.
> > +endmenu
> > diff --git a/drivers/clk/ralink/Makefile b/drivers/clk/ralink/Makefile
> > new file mode 100644
> > index 000000000000..cf6f9216379d
> > --- /dev/null
> > +++ b/drivers/clk/ralink/Makefile
> > @@ -0,0 +1,2 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +obj-$(CONFIG_CLK_MT7621) += clk-mt7621.o
> > diff --git a/drivers/clk/ralink/clk-mt7621.c b/drivers/clk/ralink/clk-mt7621.c
> > new file mode 100644
> > index 000000000000..6aea5accd51c
> > --- /dev/null
> > +++ b/drivers/clk/ralink/clk-mt7621.c
> > @@ -0,0 +1,528 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Mediatek MT7621 Clock Driver
> > + * Author: Sergio Paracuellos <[email protected]>
> > + */
> > +
> > +#include <linux/bitfield.h>
> > +#include <linux/bitops.h>
> > +#include <linux/clk-provider.h>
> > +#include <linux/clk.h>
> > +#include <linux/mfd/syscon.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/regmap.h>
> > +#include <linux/slab.h>
> > +#include <dt-bindings/clock/mt7621-clk.h>
> > +
> > +/* Configuration registers */
> > +#define SYSC_REG_SYSTEM_CONFIG0 0x10
> > +#define SYSC_REG_SYSTEM_CONFIG1 0x14
> > +#define SYSC_REG_CLKCFG0 0x2c
> > +#define SYSC_REG_CLKCFG1 0x30
> > +#define SYSC_REG_CUR_CLK_STS 0x44
> > +#define MEMC_REG_CPU_PLL 0x648
> > +
> > +#define XTAL_MODE_SEL_MASK GENMASK(8, 6)
> > +#define CPU_CLK_SEL_MASK GENMASK(31, 30)
> > +#define CUR_CPU_FDIV_MASK GENMASK(12, 8)
> > +#define CUR_CPU_FFRAC_MASK GENMASK(4, 0)
> > +#define CPU_PLL_PREDIV_MASK GENMASK(13, 12)
> > +#define CPU_PLL_FBDIV_MASK GENMASK(10, 4)
> > +
> > +struct mt7621_clk_priv {
> > + struct regmap *sysc;
> > + struct regmap *memc;
> > +};
> > +
> > +struct mt7621_clk {
> > + struct clk_hw hw;
> > + struct mt7621_clk_priv *priv;
> > +};
> > +
> > +struct mt7621_fixed_clk {
> > + u8 idx;
> > + const char *name;
> > + const char *parent_name;
> > + unsigned long rate;
> > + struct clk_hw *hw;
> > +};
> > +
> > +struct mt7621_gate {
> > + u8 idx;
> > + const char *name;
> > + const char *parent_name;
> > + struct mt7621_clk_priv *priv;
> > + u32 bit_idx;
> > + struct clk_hw hw;
> > +};
> > +
> > +#define GATE(_id, _name, _pname, _shift) \
> > + { \
> > + .idx = _id, \
> > + .name = _name, \
> > + .parent_name = _pname, \
> > + .bit_idx = _shift \
> > + }
> > +
> > +static struct mt7621_gate mt7621_gates[] = {
> > + GATE(MT7621_CLK_HSDMA, "hsdma", "150m", BIT(5)),
> > + GATE(MT7621_CLK_FE, "fe", "250m", BIT(6)),
> > + GATE(MT7621_CLK_SP_DIVTX, "sp_divtx", "270m", BIT(7)),
> > + GATE(MT7621_CLK_TIMER, "timer", "50m", BIT(8)),
> > + GATE(MT7621_CLK_PCM, "pcm", "270m", BIT(11)),
> > + GATE(MT7621_CLK_PIO, "pio", "50m", BIT(13)),
> > + GATE(MT7621_CLK_GDMA, "gdma", "bus", BIT(14)),
> > + GATE(MT7621_CLK_NAND, "nand", "125m", BIT(15)),
> > + GATE(MT7621_CLK_I2C, "i2c", "50m", BIT(16)),
> > + GATE(MT7621_CLK_I2S, "i2s", "270m", BIT(17)),
> > + GATE(MT7621_CLK_SPI, "spi", "bus", BIT(18)),
> > + GATE(MT7621_CLK_UART1, "uart1", "50m", BIT(19)),
> > + GATE(MT7621_CLK_UART2, "uart2", "50m", BIT(20)),
> > + GATE(MT7621_CLK_UART3, "uart3", "50m", BIT(21)),
> > + GATE(MT7621_CLK_ETH, "eth", "50m", BIT(23)),
> > + GATE(MT7621_CLK_PCIE0, "pcie0", "125m", BIT(24)),
> > + GATE(MT7621_CLK_PCIE1, "pcie1", "125m", BIT(25)),
> > + GATE(MT7621_CLK_PCIE2, "pcie2", "125m", BIT(26)),
> > + GATE(MT7621_CLK_CRYPTO, "crypto", "250m", BIT(29)),
> > + GATE(MT7621_CLK_SHXC, "shxc", "50m", BIT(30))
> > +};
> > +
> > +static inline struct mt7621_gate *to_mt7621_gate(struct clk_hw *hw)
> > +{
> > + return container_of(hw, struct mt7621_gate, hw);
> > +}
> > +
> > +static int mt7621_gate_enable(struct clk_hw *hw)
> > +{
> > + struct mt7621_gate *clk_gate = to_mt7621_gate(hw);
> > + struct regmap *sysc = clk_gate->priv->sysc;
> > +
> > + return regmap_update_bits(sysc, SYSC_REG_CLKCFG1,
> > + clk_gate->bit_idx, clk_gate->bit_idx);
> > +}
> > +
> > +static void mt7621_gate_disable(struct clk_hw *hw)
> > +{
> > + struct mt7621_gate *clk_gate = to_mt7621_gate(hw);
> > + struct regmap *sysc = clk_gate->priv->sysc;
> > +
> > + regmap_update_bits(sysc, SYSC_REG_CLKCFG1, clk_gate->bit_idx, 0);
> > +}
> > +
> > +static int mt7621_gate_is_enabled(struct clk_hw *hw)
> > +{
> > + struct mt7621_gate *clk_gate = to_mt7621_gate(hw);
> > + struct regmap *sysc = clk_gate->priv->sysc;
> > + u32 val;
> > +
> > + if (regmap_read(sysc, SYSC_REG_CLKCFG1, &val))
> > + return 0;
> > +
> > + return val & BIT(clk_gate->bit_idx);
> > +}
> > +
> > +static const struct clk_ops mt7621_gate_ops = {
> > + .enable = mt7621_gate_enable,
> > + .disable = mt7621_gate_disable,
> > + .is_enabled = mt7621_gate_is_enabled,
> > +};
> > +
> > +static int mt7621_gate_ops_init(struct device *dev,
> > + struct mt7621_gate *sclk)
> > +{
> > + struct clk_init_data init = {
> > + .flags = CLK_SET_RATE_PARENT,
> > + .num_parents = 1,
> > + .parent_names = &sclk->parent_name,
> > + .ops = &mt7621_gate_ops,
> > + .name = sclk->name,
> > + };
> > +
> > + sclk->hw.init = &init;
> > + return devm_clk_hw_register(dev, &sclk->hw);
> > +}
> > +
> > +static int mt7621_register_gates(struct device *dev,
> > + struct clk_hw_onecell_data *clk_data,
> > + struct mt7621_clk_priv *priv)
> > +{
> > + struct clk_hw **hws = clk_data->hws;
> > + int ret, i;
> > +
> > + for (i = 0; i < ARRAY_SIZE(mt7621_gates); i++) {
> > + struct mt7621_gate *sclk = &mt7621_gates[i];
> > +
> > + sclk->priv = priv;
> > + ret = mt7621_gate_ops_init(dev, sclk);
> > + if (ret) {
> > + dev_err(dev, "Couldn't register clock %s\n", sclk->name);
> > + goto err_clk_unreg;
> > + }
> > +
> > + hws[sclk->idx] = &sclk->hw;
> > + }
> > +
> > + return 0;
> > +
> > +err_clk_unreg:
> > + while (--i >= 0) {
> > + struct mt7621_gate *sclk = &mt7621_gates[i];
> > +
> > + clk_hw_unregister(&sclk->hw);
> > + }
> > + return ret;
> > +}
> > +
> > +#define FIXED(_id, _name, _rate) \
> > + { \
> > + .idx = _id, \
> > + .name = _name, \
> > + .parent_name = "xtal", \
> > + .rate = _rate \
> > + }
> > +
> > +static struct mt7621_fixed_clk mt7621_fixed_clks[] = {
> > + FIXED(MT7621_CLK_50M, "50m", 50000000),
> > + FIXED(MT7621_CLK_125M, "125m", 125000000),
> > + FIXED(MT7621_CLK_150M, "150m", 150000000),
> > + FIXED(MT7621_CLK_250M, "250m", 250000000),
> > + FIXED(MT7621_CLK_270M, "270m", 270000000),
> > +};
> > +
> > +static int mt7621_register_fixed_clocks(struct device *dev,
> > + struct clk_hw_onecell_data *clk_data)
> > +{
> > + struct clk_hw **hws = clk_data->hws;
> > + int ret, i;
> > +
> > + for (i = 0; i < ARRAY_SIZE(mt7621_fixed_clks); i++) {
> > + struct mt7621_fixed_clk *sclk = &mt7621_fixed_clks[i];
> > +
> > + sclk->hw = clk_hw_register_fixed_rate(dev, sclk->name,
> > + sclk->parent_name, 0,
> > + sclk->rate);
> > + if (IS_ERR(sclk->hw)) {
> > + dev_err(dev, "Couldn't register clock %s\n", sclk->name);
> > + ret = PTR_ERR(sclk->hw);
> > + goto err_clk_unreg;
> > + }
> > +
> > + hws[sclk->idx] = sclk->hw;
> > + }
> > +
> > + return 0;
> > +
> > +err_clk_unreg:
> > + while (--i >= 0) {
> > + struct mt7621_fixed_clk *sclk = &mt7621_fixed_clks[i];
> > +
> > + clk_hw_unregister_fixed_rate(sclk->hw);
> > + }
> > + return ret;
> > +}
> > +
> > +static inline struct mt7621_clk *to_mt7621_clk(struct clk_hw *hw)
> > +{
> > + return container_of(hw, struct mt7621_clk, hw);
> > +}
> > +
> > +static unsigned long mt7621_xtal_recalc_rate(struct clk_hw *hw,
> > + unsigned long parent_rate)
> > +{
> > + struct mt7621_clk *clk = to_mt7621_clk(hw);
> > + struct regmap *sysc = clk->priv->sysc;
> > + u32 val;
> > +
> > + regmap_read(sysc, SYSC_REG_SYSTEM_CONFIG0, &val);
> > + val = FIELD_GET(XTAL_MODE_SEL_MASK, val);
> > +
> > + if (val <= 2)
> > + return 20000000;
> > + if (val <= 5)
> > + return 40000000;
> > +
> > + return 25000000;
> > +}
> > +
> > +static unsigned long mt7621_cpu_recalc_rate(struct clk_hw *hw,
> > + unsigned long xtal_clk)
> > +{
> > + static const u32 prediv_tbl[] = { 0, 1, 2, 2 };
> > + struct mt7621_clk *clk = to_mt7621_clk(hw);
> > + struct regmap *sysc = clk->priv->sysc;
> > + struct regmap *memc = clk->priv->memc;
> > + u32 clkcfg, clk_sel, curclk, ffiv, ffrac;
> > + u32 pll, prediv, fbdiv;
> > + unsigned long cpu_clk;
> > +
> > + regmap_read(sysc, SYSC_REG_CLKCFG0, &clkcfg);
> > + clk_sel = FIELD_GET(CPU_CLK_SEL_MASK, clkcfg);
> > +
> > + regmap_read(sysc, SYSC_REG_CUR_CLK_STS, &curclk);
> > + ffiv = FIELD_GET(CUR_CPU_FDIV_MASK, curclk);
> > + ffrac = FIELD_GET(CUR_CPU_FFRAC_MASK, curclk);
> > +
> > + switch (clk_sel) {
> > + case 0:
> > + cpu_clk = 500000000;
> > + break;
> > + case 1:
> > + regmap_read(memc, MEMC_REG_CPU_PLL, &pll);
> > + fbdiv = FIELD_GET(CPU_PLL_FBDIV_MASK, pll);
> > + prediv = FIELD_GET(CPU_PLL_PREDIV_MASK, pll);
> > + cpu_clk = ((fbdiv + 1) * xtal_clk) >> prediv_tbl[prediv];
> > + break;
> > + default:
> > + cpu_clk = xtal_clk;
> > + }
> > +
> > + return cpu_clk / ffiv * ffrac;
> > +}
> > +
> > +static unsigned long mt7621_bus_recalc_rate(struct clk_hw *hw,
> > + unsigned long parent_rate)
> > +{
> > + return parent_rate / 4;
> > +}
> > +
> > +#define CLK_BASE(_name, _parent, _recalc) { \
> > + .init = &(struct clk_init_data) { \
> > + .name = _name, \
> > + .ops = &(const struct clk_ops) { \
> > + .recalc_rate = _recalc, \
> > + }, \
> > + .parent_data = &(const struct clk_parent_data) { \
> > + .name = _parent, \
> > + .fw_name = _parent \
> > + }, \
> > + .num_parents = _parent ? 1 : 0 \
> > + }, \
> > +}
> > +
> > +static struct mt7621_clk mt7621_clks_base[] = {
> > + { CLK_BASE("xtal", NULL, mt7621_xtal_recalc_rate) },
> > + { CLK_BASE("cpu", "xtal", mt7621_cpu_recalc_rate) },
> > + { CLK_BASE("bus", "cpu", mt7621_bus_recalc_rate) },
> > +};
> > +
> > +static struct clk_hw *mt7621_clk_early[MT7621_CLK_MAX];
> > +
> > +static int mt7621_register_early_clocks(struct device_node *np,
> > + struct clk_hw_onecell_data *clk_data,
> > + struct mt7621_clk_priv *priv)
> > +{
> > + struct clk_hw **hws = clk_data->hws;
> > + int ret, i, j;
> > +
> > + for (i = 0; i < ARRAY_SIZE(mt7621_clks_base); i++) {
> > + struct mt7621_clk *sclk = &mt7621_clks_base[i];
> > +
> > + sclk->priv = priv;
> > + ret = of_clk_hw_register(np, &sclk->hw);
> > + if (ret) {
> > + pr_err("Couldn't register top clock %i\n", i);
> > + goto err_clk_unreg;
> > + }
> > +
> > + hws[i] = &sclk->hw;
> > + mt7621_clk_early[i] = &sclk->hw;
> > + }
> > +
> > + for (j = i; j < MT7621_CLK_MAX; j++)
> > + mt7621_clk_early[j] = ERR_PTR(-EPROBE_DEFER);
> > +
> > + return 0;
> > +
> > +err_clk_unreg:
> > + while (--i >= 0) {
> > + struct mt7621_clk *sclk = &mt7621_clks_base[i];
>
> Please move sclk to the toplevel of this function instead of having it
> twice.

Ok, no problem at all. I'll move this to void to declare twice in
success and error paths.

>
> > +
> > + clk_hw_unregister(&sclk->hw);
> > + }
> > + return ret;
> > +}
> > +
> > +static int mt7621_prepare_enable_clocks(struct clk_hw_onecell_data *clk_data)
> > +{
> > + int ret, i;
> > +
> > + for (i = 0; i < MT7621_CLK_MAX; i++) {
> > + ret = clk_prepare_enable(clk_data->hws[i]->clk);
>
> Are these critical clks? Why not use the CLK_IS_CRITICAL flag?

Well, Not calling clk_prepare_enable here makes the kernel to disable
all of the stuff is not being requested. Since until now no clock
driver existed, some SoC drivers were not prepared for the clock. So,
if you prefer to avoid disabling stuff using this flag I think I can
just remove this enable_clocks function and set the flags for all the
clocks when registering them.

> > + if (ret) {
> > + pr_err("failed to enable clk: %d\n", ret);
> > + goto err_clk_disable;
> > + }
> > + }
> > +
> > + return 0;
> > +
> > +err_clk_disable:
> > + while (--i >= 0)
> > + clk_disable_unprepare(clk_data->hws[i]->clk);
> > + return ret;
> > +}
> > +
> > +static void __init mt7621_clk_init(struct device_node *node)
> > +{
> > + struct mt7621_clk_priv *priv;
> > + struct clk_hw_onecell_data *clk_data;
> > + int ret, i, count;
> > +
> > + priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> > + if (!priv)
> > + return;
> > +
> > + priv->sysc = syscon_node_to_regmap(node);
> > + if (IS_ERR(priv->sysc)) {
> > + pr_err("Could not get sysc syscon regmap\n");
> > + goto free_clk_priv;
> > + }
> > +
> > + priv->memc = syscon_regmap_lookup_by_phandle(node, "ralink,memctl");
> > + if (IS_ERR(priv->memc)) {
> > + pr_err("Could not get memc syscon regmap\n");
> > + goto free_clk_priv;
> > + }
> > +
> > + count = ARRAY_SIZE(mt7621_clks_base) +
> > + ARRAY_SIZE(mt7621_fixed_clks) + ARRAY_SIZE(mt7621_gates);
> > + clk_data = kzalloc(struct_size(clk_data, hws, count), GFP_KERNEL);
> > + if (!clk_data)
> > + goto free_clk_priv;
> > +
> > + ret = mt7621_register_early_clocks(node, clk_data, priv);
> > + if (ret) {
> > + pr_err("Couldn't register top clocks\n");
> > + goto free_clk_data;
> > + }
> > +
> > + clk_data->num = count;
> > +
> > + ret = of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);
> > + if (ret) {
> > + pr_err("Couldn't add clk hw provider\n");
> > + goto unreg_clk_top;
> > + }
> > +
> > + return;
> > +
> > +unreg_clk_top:
> > + for (i = 0; i < ARRAY_SIZE(mt7621_clks_base); i++) {
> > + struct mt7621_clk *sclk = &mt7621_clks_base[i];
> > +
> > + clk_hw_unregister(&sclk->hw);
> > + }
> > +
> > +free_clk_data:
> > + kfree(clk_data);
> > +
> > +free_clk_priv:
> > + kfree(priv);
> > +}
> > +CLK_OF_DECLARE_DRIVER(mt7621_clk, "mediatek,mt7621-sysc", mt7621_clk_init);
> > +
> > +static int mt7621_clk_probe(struct platform_device *pdev)
> > +{
> > + struct device_node *np = pdev->dev.of_node;
> > + struct clk_hw_onecell_data *clk_data;
> > + struct device *dev = &pdev->dev;
> > + struct mt7621_clk_priv *priv;
> > + int ret, i, count;
> > +
> > + priv = kzalloc(sizeof(*priv), GFP_KERNEL);
>
> Can we use devm_* APIs here?

Ok, I will.

>
> > + if (!priv)
> > + return -ENOMEM;
> > +
> > + priv->sysc = syscon_node_to_regmap(np);
> > + if (IS_ERR(priv->sysc)) {
> > + ret = PTR_ERR(priv->sysc);
> > + dev_err(dev, "Could not get sysc syscon regmap\n");
> > + goto free_clk_priv;
> > + }
> > +
> > + priv->memc = syscon_regmap_lookup_by_phandle(np, "ralink,memctl");
> > + if (IS_ERR(priv->memc)) {
> > + ret = PTR_ERR(priv->memc);
> > + dev_err(dev, "Could not get memc syscon regmap\n");
> > + goto free_clk_priv;
> > + }
> > +
> > + count = ARRAY_SIZE(mt7621_clks_base) +
> > + ARRAY_SIZE(mt7621_fixed_clks) + ARRAY_SIZE(mt7621_gates);
> > + clk_data = kzalloc(struct_size(clk_data, hws, count), GFP_KERNEL);
> > + if (!clk_data) {
> > + ret = -ENOMEM;
> > + goto free_clk_priv;
> > + }
> > +
> > + for (i = 0; i < ARRAY_SIZE(mt7621_clks_base); i++)
> > + clk_data->hws[i] = mt7621_clk_early[i];
> > +
> > + ret = mt7621_register_fixed_clocks(dev, clk_data);
> > + if (ret) {
> > + dev_err(dev, "Couldn't register fixed clocks\n");
> > + goto free_clk_data;
> > + }
> > +
> > + ret = mt7621_register_gates(dev, clk_data, priv);
> > + if (ret) {
> > + dev_err(dev, "Couldn't register fixed clock gates\n");
> > + goto unreg_clk_fixed;
> > + }
> > +
> > + clk_data->num = count;
> > +
> > + ret = mt7621_prepare_enable_clocks(clk_data);
> > + if (ret) {
> > + dev_err(dev, "Couldn't register fixed clock gates\n");
>
> This isn't registering fixed clock gates though?

Copy paste is a bad thing ;). Will fix this.

>
> > + goto unreg_clk_gates;
> > + }
> > +
> > + ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, clk_data);
> > + if (ret) {
> > + dev_err(dev, "Couldn't add clk hw provider\n");
> > + goto disable_clks;
> > + }
> > +
> > + return 0;
> > +
> > +disable_clks:
> > + for (i = 0; i < MT7621_CLK_MAX; i++)
> > + clk_disable_unprepare(clk_data->hws[i]->clk);
> > +
> > +unreg_clk_gates:
> > + for (i = 0; i < ARRAY_SIZE(mt7621_gates); i++) {
> > + struct mt7621_gate *sclk = &mt7621_gates[i];
> > +
> > + clk_hw_unregister(&sclk->hw);
> > + }
> > +
> > +unreg_clk_fixed:
> > + for (i = 0; i < ARRAY_SIZE(mt7621_fixed_clks); i++) {
> > + struct mt7621_fixed_clk *sclk = &mt7621_fixed_clks[i];
> > +
> > + clk_hw_unregister_fixed_rate(sclk->hw);
> > + }
> > +
> > +free_clk_data:
> > + kfree(clk_data);
> > +
> > +free_clk_priv:
> > + kfree(priv);
> > +
> > + return ret;
> > +}
> > +
> > +static const struct of_device_id mt7621_clk_of_match[] = {
> > + { .compatible = "mediatek,mt7621-sysc" },
> > + {},
>
> Nitpick: Drop the comma on the sentinel so it's a compile error if
> another element is added after.

True, will drop in next version.

>
> > +};
> > +
> > +static struct platform_driver mt7621_clk_driver = {
> > + .probe = mt7621_clk_probe,
> > + .driver = {
> > + .name = "mt7621-clk",
> > + .of_match_table = mt7621_clk_of_match,
> > + },
> > +};
> > +builtin_platform_driver(mt7621_clk_driver);

Thanks for the review. I will resend this fixed during this weekend.

Best regards,
Sergio Paracuellos