[PATCH v4 08/25] clk: mtmips: add clock driver for MediaTek MT7621 SoC
Sean Anderson
seanga2 at gmail.com
Wed May 11 18:29:24 CEST 2022
Hi Weijie,
I found a copy of the MT7260 programming guide, which I am using
as a reference. I assume that they have not diverged too much,
but presumably most discrepencies will be accounted for in the
difference in part numbers.
On 5/10/22 8:18 AM, Weijie Gao wrote:
> This patch adds a clock driver for MediaTek MT7621 SoC.
> This driver provides clock gate control as well as getting clock frequency
> for CPU/SYS/XTAL and some peripherals.
>
> Signed-off-by: Weijie Gao <weijie.gao at mediatek.com>
> ---
> v4 changes: none
> v3 changes: update clock definitions to match upstream kernel
> v2 changes: none
> ---
> drivers/clk/mtmips/Makefile | 1 +
> drivers/clk/mtmips/clk-mt7621.c | 315 +++++++++++++++++++++++++
> include/dt-bindings/clock/mt7621-clk.h | 46 ++++
> 3 files changed, 362 insertions(+)
> create mode 100644 drivers/clk/mtmips/clk-mt7621.c
> create mode 100644 include/dt-bindings/clock/mt7621-clk.h
>
> diff --git a/drivers/clk/mtmips/Makefile b/drivers/clk/mtmips/Makefile
> index 732e7f2545..ee8b5afe87 100644
> --- a/drivers/clk/mtmips/Makefile
> +++ b/drivers/clk/mtmips/Makefile
> @@ -1,4 +1,5 @@
> # SPDX-License-Identifier: GPL-2.0
>
> obj-$(CONFIG_SOC_MT7620) += clk-mt7620.o
> +obj-$(CONFIG_SOC_MT7621) += clk-mt7621.o
> obj-$(CONFIG_SOC_MT7628) += clk-mt7628.o
> diff --git a/drivers/clk/mtmips/clk-mt7621.c b/drivers/clk/mtmips/clk-mt7621.c
> new file mode 100644
> index 0000000000..e8203016a5
> --- /dev/null
> +++ b/drivers/clk/mtmips/clk-mt7621.c
> @@ -0,0 +1,315 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2022 MediaTek Inc. All rights reserved.
> + *
> + * Author: Weijie Gao <weijie.gao at mediatek.com>
> + */
> +
> +#include <common.h>
> +#include <clk-uclass.h>
> +#include <dm.h>
> +#include <dm/device_compat.h>
> +#include <regmap.h>
> +#include <syscon.h>
> +#include <dt-bindings/clock/mt7621-clk.h>
> +#include <linux/bitops.h>
> +#include <linux/io.h>
> +
> +#define SYSC_MAP_SIZE 0x100
> +#define MEMC_MAP_SIZE 0x1000
> +
> +/* SYSC */
> +#define SYSCFG0_REG 0x10
> +#define XTAL_MODE_SEL_S 6
> +#define XTAL_MODE_SEL_M 0x1c0
Please use GENMASK and BIT for these defines.
> +
> +#define CLKCFG0_REG 0x2c
> +#define CPU_CLK_SEL_S 30
> +#define CPU_CLK_SEL_M 0xc0000000
> +#define PERI_CLK_SEL 0x10
> +
> +#define CLKCFG1_REG 0x30
> +
> +#define CUR_CLK_STS_REG 0x44
> +#define CUR_CPU_FDIV_S 8
> +#define CUR_CPU_FDIV_M 0x1f00
> +#define CUR_CPU_FFRAC_S 0
> +#define CUR_CPU_FFRAC_M 0x1f
> +
> +/* MEMC */
> +#define MEMPLL1_REG 0x0604
> +#define RG_MEPL_DIV2_SEL_S 1
> +#define RG_MEPL_DIV2_SEL_M 0x06
> +
> +#define MEMPLL6_REG 0x0618
> +#define MEMPLL18_REG 0x0648
> +#define RG_MEPL_PREDIV_S 12
> +#define RG_MEPL_PREDIV_M 0x3000
> +#define RG_MEPL_FBDIV_S 4
> +#define RG_MEPL_FBDIV_M 0x7f0
> +
> +/* EPLL clock */
> +#define EPLL_CLK 50000000
> +
> +struct mt7621_clk_priv {
> + void __iomem *sysc_base;
> + void __iomem *memc_base;
> + int cpu_clk;
> + int ddr_clk;
> + int sys_clk;
> + int xtal_clk;
> +};
> +
> +enum mt7621_clk_src {
> + CLK_SRC_CPU,
> + CLK_SRC_DDR,
> + CLK_SRC_SYS,
> + CLK_SRC_XTAL,
> + CLK_SRC_PERI,
> + CLK_SRC_125M,
> + CLK_SRC_150M,
> + CLK_SRC_250M,
> + CLK_SRC_270M,
> +
> + __CLK_SRC_MAX
> +};
> +
> +struct mt7621_clk_map {
> + u32 cgbit;
> + enum mt7621_clk_src clksrc;
> +};
> +
> +#define CLK_MAP(_id, _cg, _src) \
> + [_id] = { .cgbit = (_cg), .clksrc = (_src) }
> +
> +#define CLK_MAP_SRC(_id, _src) \
> + [_id] = { .cgbit = UINT32_MAX, .clksrc = (_src) }
> +
> +static const struct mt7621_clk_map mt7621_clk_mappings[] = {
> + CLK_MAP_SRC(MT7621_CLK_XTAL, CLK_SRC_XTAL),
> + CLK_MAP_SRC(MT7621_CLK_CPU, CLK_SRC_CPU),
> + CLK_MAP_SRC(MT7621_CLK_BUS, CLK_SRC_SYS),
> + CLK_MAP_SRC(MT7621_CLK_50M, CLK_SRC_PERI),
> + CLK_MAP_SRC(MT7621_CLK_125M, CLK_SRC_125M),
> + CLK_MAP_SRC(MT7621_CLK_150M, CLK_SRC_150M),
> + CLK_MAP_SRC(MT7621_CLK_250M, CLK_SRC_250M),
> + CLK_MAP_SRC(MT7621_CLK_270M, CLK_SRC_270M),
> +
> + CLK_MAP(MT7621_CLK_HSDMA, 5, CLK_SRC_150M),
> + CLK_MAP(MT7621_CLK_FE, 6, CLK_SRC_250M),
> + CLK_MAP(MT7621_CLK_SP_DIVTX, 7, CLK_SRC_270M),
> + CLK_MAP(MT7621_CLK_TIMER, 8, CLK_SRC_PERI),
> + CLK_MAP(MT7621_CLK_PCM, 11, CLK_SRC_270M),
> + CLK_MAP(MT7621_CLK_PIO, 13, CLK_SRC_PERI),
> + CLK_MAP(MT7621_CLK_GDMA, 14, CLK_SRC_SYS),
> + CLK_MAP(MT7621_CLK_NAND, 15, CLK_SRC_125M),
> + CLK_MAP(MT7621_CLK_I2C, 16, CLK_SRC_PERI),
> + CLK_MAP(MT7621_CLK_I2S, 17, CLK_SRC_270M),
Should this be PERI?
> + CLK_MAP(MT7621_CLK_SPI, 18, CLK_SRC_SYS),
> + CLK_MAP(MT7621_CLK_UART1, 19, CLK_SRC_PERI),
> + CLK_MAP(MT7621_CLK_UART2, 20, CLK_SRC_PERI),
> + CLK_MAP(MT7621_CLK_UART3, 21, CLK_SRC_PERI),
> + CLK_MAP(MT7621_CLK_ETH, 23, CLK_SRC_PERI),
> + CLK_MAP(MT7621_CLK_PCIE0, 24, CLK_SRC_125M),
> + CLK_MAP(MT7621_CLK_PCIE1, 25, CLK_SRC_125M),
> + CLK_MAP(MT7621_CLK_PCIE2, 26, CLK_SRC_125M),
> + CLK_MAP(MT7621_CLK_CRYPTO, 29, CLK_SRC_250M),
> + CLK_MAP(MT7621_CLK_SHXC, 30, CLK_SRC_PERI),
> +
> + CLK_MAP_SRC(MT7621_CLK_MAX, __CLK_SRC_MAX),
> +
> + CLK_MAP_SRC(MT7621_CLK_DDR, CLK_SRC_DDR),
> +};
> +
> +static ulong mt7621_clk_get_rate(struct clk *clk)
> +{
> + struct mt7621_clk_priv *priv = dev_get_priv(clk->dev);
> + u32 val;
> +
> + if (clk->id >= ARRAY_SIZE(mt7621_clk_mappings))
> + return 0;
Do this check in request().
> +
> + switch (mt7621_clk_mappings[clk->id].clksrc) {
> + case CLK_SRC_CPU:
> + return priv->cpu_clk;
> + case CLK_SRC_DDR:
> + return priv->ddr_clk;
> + case CLK_SRC_SYS:
> + return priv->sys_clk;
> + case CLK_SRC_XTAL:
> + return priv->xtal_clk;
> + case CLK_SRC_PERI:
> + val = readl(priv->sysc_base + CLKCFG0_REG);
> + if (val & PERI_CLK_SEL)
> + return priv->xtal_clk;
> + else
> + return EPLL_CLK;
Shouldn't this be a proper clock like the CLK_SRC_XXXMs? In the
7620 this is (BBP PLL)/12 (aka the parent of PCM_480). I assume
that this setup is different on this SoC?
> + case CLK_SRC_125M:
> + return 125000000;
> + case CLK_SRC_150M:
> + return 150000000;
> + case CLK_SRC_250M:
> + return 250000000;
> + case CLK_SRC_270M:
> + return 270000000;
> + default:
> + return 0;
> + }
> +}
> +
> +static int mt7621_clk_enable(struct clk *clk)
> +{
> + struct mt7621_clk_priv *priv = dev_get_priv(clk->dev);
> + u32 cgbit;
> +
> + if (clk->id >= ARRAY_SIZE(mt7621_clk_mappings))
> + return -1;
Please use a real error code (e.g. ENOENT)
> + cgbit = mt7621_clk_mappings[clk->id].cgbit;
> + if (cgbit == UINT32_MAX)
> + return -1;
return -ENOSYS
> +
> + setbits_32(priv->sysc_base + CLKCFG1_REG, BIT(cgbit));
> +
> + return 0;
> +}
> +
> +static int mt7621_clk_disable(struct clk *clk)
> +{
> + struct mt7621_clk_priv *priv = dev_get_priv(clk->dev);
> + u32 cgbit;
> +
> + if (clk->id >= ARRAY_SIZE(mt7621_clk_mappings))
> + return -1;
> +
> + cgbit = mt7621_clk_mappings[clk->id].cgbit;
> + if (cgbit == UINT32_MAX)
> + return -1;
> +
> + clrbits_32(priv->sysc_base + CLKCFG1_REG, BIT(cgbit));
> +
> + return 0;
> +}
ditto
> +
> +const struct clk_ops mt7621_clk_ops = {
> + .enable = mt7621_clk_enable,
> + .disable = mt7621_clk_disable,
> + .get_rate = mt7621_clk_get_rate,
> +};
> +
> +static void mt7621_get_clocks(struct mt7621_clk_priv *priv)
> +{
> + u32 bs, xtal_sel, clkcfg0, cur_clk, mempll, dividx, fb;
> + u32 xtal_clk, xtal_div, ffiv, ffrac, cpu_clk, ddr_clk;
> + static const u32 xtal_div_tbl[] = {0, 1, 2, 2};
> +
> + bs = readl(priv->sysc_base + SYSCFG0_REG);
> + clkcfg0 = readl(priv->sysc_base + CLKCFG0_REG);
> + cur_clk = readl(priv->sysc_base + CUR_CLK_STS_REG);
> +
> + xtal_sel = (bs & XTAL_MODE_SEL_M) >> XTAL_MODE_SEL_S;
> +
> + if (xtal_sel <= 2)
> + xtal_clk = 20 * 1000 * 1000;
> + else if (xtal_sel <= 5)
> + xtal_clk = 40 * 1000 * 1000;
> + else
> + xtal_clk = 25 * 1000 * 1000;
> +
> + switch ((clkcfg0 & CPU_CLK_SEL_M) >> CPU_CLK_SEL_S) {
> + case 0:
> + cpu_clk = 500 * 1000 * 1000;
> + break;
> + case 1:
> + mempll = readl(priv->memc_base + MEMPLL18_REG);
> + dividx = (mempll & RG_MEPL_PREDIV_M) >> RG_MEPL_PREDIV_S;
> + fb = (mempll & RG_MEPL_FBDIV_M) >> RG_MEPL_FBDIV_S;
> + xtal_div = 1 << xtal_div_tbl[dividx];
> + cpu_clk = (fb + 1) * xtal_clk / xtal_div;
> + break;
> + default:
> + cpu_clk = xtal_clk;
> + }
> +
> + ffiv = (cur_clk & CUR_CPU_FDIV_M) >> CUR_CPU_FDIV_S;
> + ffrac = (cur_clk & CUR_CPU_FFRAC_M) >> CUR_CPU_FFRAC_S;
> + cpu_clk = cpu_clk / ffiv * ffrac;
> +
> + mempll = readl(priv->memc_base + MEMPLL6_REG);
> + dividx = (mempll & RG_MEPL_PREDIV_M) >> RG_MEPL_PREDIV_S;
> + fb = (mempll & RG_MEPL_FBDIV_M) >> RG_MEPL_FBDIV_S;
> + xtal_div = 1 << xtal_div_tbl[dividx];
> + ddr_clk = fb * xtal_clk / xtal_div;
> +
> + bs = readl(priv->memc_base + MEMPLL1_REG);
> + if (((bs & RG_MEPL_DIV2_SEL_M) >> RG_MEPL_DIV2_SEL_S) == 0)
> + ddr_clk *= 2;
> +
> + priv->cpu_clk = cpu_clk;
> + priv->sys_clk = cpu_clk / 4;
> + priv->ddr_clk = ddr_clk;
> + priv->xtal_clk = xtal_clk;
> +}
I would generally like to see these calculations done in get_rate
(to allow for set_rate), but this style is fine .
> +static int mt7621_clk_probe(struct udevice *dev)
> +{
> + struct mt7621_clk_priv *priv = dev_get_priv(dev);
> + struct ofnode_phandle_args args;
> + struct regmap *regmap;
> + void __iomem *base;
> + int ret;
> +
> + /* get corresponding sysc phandle */
> + ret = dev_read_phandle_with_args(dev, "mediatek,sysc", NULL, 0, 0,
> + &args);
> + if (ret)
> + return ret;
I think it might be better to have this node be a child of the sysc. Like
sysc: sysc at 1e000000 {
compatible = "mediatek,mt7621-sysc", "syscon";
reg = <0x1e000000 0x100>;
u-boot,dm-pre-reloc;
clkctrl: clock-controller {
compatible = "mediatek,mt7621-clk";
mediatek,memc = <&memc>;
#clock-cells = <1>;
};
rstctrl: reset-controller {
compatible = "mediatek,mtmips-reset";
#reset-cells = <1>;
};
reboot {
compatible = "resetctl-reboot";
resets = <&rstctrl RST_SYS>;
reset-names = "sysreset";
};
};
And then do something like
base = dev_read_addr_ptr(dev_get_parent(dev));
if (!priv->base)
return -EINVAL;
> + regmap = syscon_node_to_regmap(args.node);
> + if (IS_ERR(regmap))
> + return PTR_ERR(regmap);
> +
> + base = regmap_get_range(regmap, 0);
> + if (!base) {
> + dev_err(dev, "Unable to find sysc\n");
> + return -ENODEV;
> + }
> +
> + priv->sysc_base = ioremap_nocache((phys_addr_t)base, SYSC_MAP_SIZE);
> +
> + /* get corresponding memc phandle */
> + ret = dev_read_phandle_with_args(dev, "mediatek,memc", NULL, 0, 0,
> + &args);
> + if (ret)
> + return ret;
> +
> + regmap = syscon_node_to_regmap(args.node);
> + if (IS_ERR(regmap))
> + return PTR_ERR(regmap);
> +
> + base = regmap_get_range(regmap, 0);
> + if (!base) {
> + dev_err(dev, "Unable to find memc\n");
> + return -ENODEV;
> + }
> +
> + priv->memc_base = ioremap_nocache((phys_addr_t)base, MEMC_MAP_SIZE);
Why not just use the regmap api?
> +
> + mt7621_get_clocks(priv);
> +
> + return 0;
> +}
> +
> +static const struct udevice_id mt7621_clk_ids[] = {
> + { .compatible = "mediatek,mt7621-clk" },
> + { }
> +};
> +
> +U_BOOT_DRIVER(mt7621_clk) = {
> + .name = "mt7621-clk",
> + .id = UCLASS_CLK,
> + .of_match = mt7621_clk_ids,
> + .probe = mt7621_clk_probe,
> + .priv_auto = sizeof(struct mt7621_clk_priv),
> + .ops = &mt7621_clk_ops,
> +};
> diff --git a/include/dt-bindings/clock/mt7621-clk.h b/include/dt-bindings/clock/mt7621-clk.h
> new file mode 100644
> index 0000000000..978c67951b
> --- /dev/null
> +++ b/include/dt-bindings/clock/mt7621-clk.h
> @@ -0,0 +1,46 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2022 MediaTek Inc. All rights reserved.
> + *
> + * Author: Weijie Gao <weijie.gao at mediatek.com>
> + */
> +
> +#ifndef _DT_BINDINGS_MT7621_CLK_H_
> +#define _DT_BINDINGS_MT7621_CLK_H_
> +
> +#define MT7621_CLK_XTAL 0
> +#define MT7621_CLK_CPU 1
> +#define MT7621_CLK_BUS 2
> +#define MT7621_CLK_50M 3
> +#define MT7621_CLK_125M 4
> +#define MT7621_CLK_150M 5
> +#define MT7621_CLK_250M 6
> +#define MT7621_CLK_270M 7
> +
> +#define MT7621_CLK_HSDMA 8
> +#define MT7621_CLK_FE 9
> +#define MT7621_CLK_SP_DIVTX 10
> +#define MT7621_CLK_TIMER 11
> +#define MT7621_CLK_PCM 12
> +#define MT7621_CLK_PIO 13
> +#define MT7621_CLK_GDMA 14
> +#define MT7621_CLK_NAND 15
> +#define MT7621_CLK_I2C 16
> +#define MT7621_CLK_I2S 17
> +#define MT7621_CLK_SPI 18
> +#define MT7621_CLK_UART1 19
> +#define MT7621_CLK_UART2 20
> +#define MT7621_CLK_UART3 21
> +#define MT7621_CLK_ETH 22
> +#define MT7621_CLK_PCIE0 23
> +#define MT7621_CLK_PCIE1 24
> +#define MT7621_CLK_PCIE2 25
> +#define MT7621_CLK_CRYPTO 26
> +#define MT7621_CLK_SHXC 27
> +
> +#define MT7621_CLK_MAX 28
> +
> +/* for u-boot only */
> +#define MT7621_CLK_DDR 29
> +
> +#endif /* _DT_BINDINGS_MT7621_CLK_H_ */
>
--Sean
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