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SubjectRe: [PATCH v10 2/4] clk: clk-loongson2: add clock controller driver support
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在 2023/2/11 上午7:42, Stephen Boyd 写道:
> Quoting Yinbo Zhu (2022-11-28 19:41:55)
>> diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
>> index 903096bd87f8..4f8f1b8f796d 100644
>> --- a/arch/loongarch/Kconfig
>> +++ b/arch/loongarch/Kconfig
>> @@ -127,6 +127,7 @@ config LOONGARCH
>> select USE_PERCPU_NUMA_NODE_ID
>> select USER_STACKTRACE_SUPPORT
>> select ZONE_DMA32
>> + select COMMON_CLK
> Any reason to put this at the end instead of alphabetically?
okay, I will change it as alphabetically.
>>
>> config 32BIT
>> bool
>> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
>> index d79905f3e174..d13626f63739 100644
>> --- a/drivers/clk/Kconfig
>> +++ b/drivers/clk/Kconfig
>> @@ -326,6 +326,15 @@ config COMMON_CLK_LOCHNAGAR
>> This driver supports the clocking features of the Cirrus Logic
>> Lochnagar audio development board.
>>
>> +config COMMON_CLK_LOONGSON2
>> + bool "Clock driver for Loongson-2 SoC"
>> + depends on COMMON_CLK && OF
>> + help
>> + This driver provides support for Clock Controller that base on
> Don't capitalize 'Clock Controller'
okay, I got it.
>
>> + Common Clock Framework Controller (CCF) on Loongson-2 SoC. The
> CCF doesn't really matter. Just say "support for clock controller on
> Loongson-2 SoC"
okay, I got it.
>
>> + Clock Controller can generates and supplies clock to various
> Same capitalization comment.
okay, I got it.
>
>> + peripherals within the SoC.
>> +
>> config COMMON_CLK_NXP
>> def_bool COMMON_CLK && (ARCH_LPC18XX || ARCH_LPC32XX)
>> select REGMAP_MMIO if ARCH_LPC32XX
>> diff --git a/drivers/clk/clk-loongson2.c b/drivers/clk/clk-loongson2.c
>> new file mode 100644
>> index 000000000000..7487effceeab
>> --- /dev/null
>> +++ b/drivers/clk/clk-loongson2.c
>> @@ -0,0 +1,286 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * Author: Yinbo Zhu <zhuyinbo@loongson.cn>
>> + * Copyright (C) 2022-2023 Loongson Technology Corporation Limited
>> + */
>> +
>> +#include <linux/clkdev.h>
> Drop include that isn't used.
okay, I got it.
>
>> +#include <linux/err.h>
>> +#include <linux/init.h>
>> +#include <linux/of.h>
>> +#include <linux/of_address.h>
>> +#include <dt-bindings/clock/loongson,ls2k-clk.h>
>> +#include <linux/clk-provider.h>
>> +#include <linux/slab.h>
>> +#include <linux/clk.h>
>> +
>> +#define LOONGSON2_PLL_MULT_SHIFT 32
>> +#define LOONGSON2_PLL_MULT_WIDTH 10
>> +#define LOONGSON2_PLL_DIV_SHIFT 26
>> +#define LOONGSON2_PLL_DIV_WIDTH 6
>> +#define LOONGSON2_APB_FREQSCALE_SHIFT 20
>> +#define LOONGSON2_APB_FREQSCALE_WIDTH 3
>> +#define LOONGSON2_USB_FREQSCALE_SHIFT 16
>> +#define LOONGSON2_USB_FREQSCALE_WIDTH 3
>> +#define LOONGSON2_SATA_FREQSCALE_SHIFT 12
>> +#define LOONGSON2_SATA_FREQSCALE_WIDTH 3
>> +
>> +static void __iomem *loongson2_pll_base;
>> +
>> +static struct clk_hw *loongson2_clk_register(struct device *dev,
>> + const char *name,
>> + const char *parent_name,
>> + const struct clk_ops *ops,
>> + unsigned long flags)
>> +{
>> + int ret;
>> + struct clk_hw *hw;
>> + struct clk_init_data init;
>> +
>> + /* allocate the divider */
>> + hw = kzalloc(sizeof(*hw), GFP_KERNEL);
>> + if (!hw)
>> + return ERR_PTR(-ENOMEM);
>> +
>> + init.name = name;
>> + init.ops = ops;
>> + init.flags = flags;
>> + init.parent_names = (parent_name ? &parent_name : NULL);
>> + init.num_parents = (parent_name ? 1 : 0);
>> + hw->init = &init;
>> +
>> + /* register the clock */
>> + ret = clk_hw_register(dev, hw);
>> + if (ret) {
>> + kfree(hw);
>> + hw = ERR_PTR(ret);
>> + }
>> +
>> + return hw;
>> +}
>> +
>> +static struct clk_hw *loongson2_clk_pll_register(const char *name,
>> + const char *parent, void __iomem *reg)
>> +{
>> + u64 val;
>> + u32 mult = 1, div = 1;
>> +
>> + val = readq((void *)reg);
> Drop the cast.
I will remove the (void *).
>
>> +
>> + mult = (val >> LOONGSON2_PLL_MULT_SHIFT) &
>> + clk_div_mask(LOONGSON2_PLL_MULT_WIDTH);
>> + div = (val >> LOONGSON2_PLL_DIV_SHIFT) &
>> + clk_div_mask(LOONGSON2_PLL_DIV_WIDTH);
>> +
>> + return clk_hw_register_fixed_factor(NULL, name, parent,
>> + CLK_SET_RATE_PARENT, mult, div);
>> +}
>> +
>> +static unsigned long loongson2_apb_recalc_rate(struct clk_hw *hw,
>> + unsigned long parent_rate)
>> +{
>> + u64 val;
>> + u32 mult;
>> + unsigned long rate;
>> +
>> + val = readq((void *)(loongson2_pll_base + 0x50));
> Drop the cast.
I will remove the (void *).
>
>> +
>> + mult = (val >> LOONGSON2_APB_FREQSCALE_SHIFT) &
>> + clk_div_mask(LOONGSON2_APB_FREQSCALE_WIDTH);
>> +
>> + rate = parent_rate * (mult + 1);
>> + do_div(rate, 8);
>> +
>> + return rate;
>> +}
>> +
>> +static const struct clk_ops loongson2_apb_clk_ops = {
>> + .recalc_rate = loongson2_apb_recalc_rate,
>> +};
>> +
>> +static unsigned long loongson2_usb_recalc_rate(struct clk_hw *hw,
>> + unsigned long parent_rate)
>> +{
>> + u64 val;
>> + u32 mult;
>> + unsigned long rate;
>> +
>> + val = readq((void *)(loongson2_pll_base + 0x50));
> Drop the cast.
I will remove the (void *).
>
>> +
>> + mult = (val >> LOONGSON2_USB_FREQSCALE_SHIFT) &
>> + clk_div_mask(LOONGSON2_USB_FREQSCALE_WIDTH);
>> +
>> + rate = parent_rate * (mult + 1);
>> + do_div(rate, 8);
> Why is do_div() being used?
no expecial reason, I only want to get a result that rate divide 8.
>
>> +
>> + return rate;
>> +}
>> +
>> +static const struct clk_ops loongson2_usb_clk_ops = {
>> + .recalc_rate = loongson2_usb_recalc_rate,
>> +};
>> +
>> +static unsigned long loongson2_sata_recalc_rate(struct clk_hw *hw,
>> + unsigned long parent_rate)
>> +{
>> + u64 val;
>> + u32 mult;
>> + unsigned long rate;
>> +
>> + val = readq((void *)(loongson2_pll_base + 0x50));
> Drop the cast.
I will remove the (void *).
>
>> +
>> + mult = (val >> LOONGSON2_SATA_FREQSCALE_SHIFT) &
>> + clk_div_mask(LOONGSON2_SATA_FREQSCALE_WIDTH);
>> +
>> + rate = parent_rate * (mult + 1);
>> + do_div(rate, 8);
>> +
>> + return rate;
>> +}
>> +
>> +static const struct clk_ops loongson2_sata_clk_ops = {
>> + .recalc_rate = loongson2_sata_recalc_rate,
>> +};
>> +
>> +static void loongson2_check_clk_hws(struct clk_hw *clks[], unsigned int count)
> Inline this function.
I will add it.
>
>> +{
>> + unsigned int i;
>> +
>> + for (i = 0; i < count; i++)
>> + if (IS_ERR(clks[i]))
>> + pr_err("Loongson2 clk %u: register failed with %ld\n"
>> + , i, PTR_ERR(clks[i]));
> Put the comma on the line above please.
okay, I got it.
>
>> +}
>> +
>> +static struct clk_hw *loongson2_obtain_fixed_clk_hw(
>> + struct device_node *np,
>> + const char *name)
>> +{
>> + struct clk *clk;
>> +
>> + clk = of_clk_get_by_name(np, name);
>> + if (IS_ERR(clk))
>> + return ERR_PTR(-ENOENT);
>> +
>> + return __clk_get_hw(clk);
> Please don't implement this whole function. Instead, use clk_parent_data
> and the 'fw_name' or 'index' members to assign clk parents.

at present,  the child clk doesn't depend on the clk_parent_data,   eg.

hws[LOONGSON2_NODE_PLL] = loongson2_clk_pll_register("node_pll",
"ref_100m", loongson2_pll_base);

static struct clk_hw *loongson2_clk_pll_register(const char *name,
                                const char *parent, void __iomem *reg)
{
        u64 val;
        u32 mult = 1, div = 1;

        val = readq((void *)reg);

        mult = (val >> LOONGSON2_PLL_MULT_SHIFT) &
                        clk_div_mask(LOONGSON2_PLL_MULT_WIDTH);
        div = (val >> LOONGSON2_PLL_DIV_SHIFT) &
                        clk_div_mask(LOONGSON2_PLL_DIV_WIDTH);

        return clk_hw_register_fixed_factor(NULL, name, parent,
                                CLK_SET_RATE_PARENT, mult, div);
}

you meaning is to use clk_parent_data to rework
loongson2_clk_pll_register  and drop

loongson2_obtain_fixed_clk_hw ?

>
>> +}
>> +
>> +static void __init loongson2_clocks_init(struct device_node *np)
>> +{
>> + struct clk_hw **hws;
>> + struct clk_hw_onecell_data *clk_hw_data;
>> + spinlock_t loongson2_clk_lock;
>> +
>> + loongson2_pll_base = of_iomap(np, 0);
>> +
>> + if (!loongson2_pll_base) {
>> + pr_err("clk: unable to map loongson2 clk registers\n");
>> + goto err;
> return?
sorry, I don't get it.  you meaning is that  remove "goto err". Instead,
add a "return".
>
>> + }
>> +
>> + clk_hw_data = kzalloc(struct_size(clk_hw_data, hws, LOONGSON2_CLK_END),
>> + GFP_KERNEL);
>> + if (WARN_ON(!clk_hw_data))
>> + goto err;
>> +
>> + clk_hw_data->num = LOONGSON2_CLK_END;
>> + hws = clk_hw_data->hws;
>> +
>> + hws[LOONGSON2_REF_100M] = loongson2_obtain_fixed_clk_hw(np,
>> + "ref_100m");
>> +
>> + hws[LOONGSON2_NODE_PLL] = loongson2_clk_pll_register("node_pll",
>> + "ref_100m",
>> + loongson2_pll_base);
>> +
>> + hws[LOONGSON2_DDR_PLL] = loongson2_clk_pll_register("ddr_pll",
>> + "ref_100m",
>> + loongson2_pll_base + 0x10);
>> +
>> + hws[LOONGSON2_DC_PLL] = loongson2_clk_pll_register("dc_pll",
>> + "ref_100m",
>> + loongson2_pll_base + 0x20);
>> +
>> + hws[LOONGSON2_PIX0_PLL] = loongson2_clk_pll_register("pix0_pll",
>> + "ref_100m",
>> + loongson2_pll_base + 0x30);
>> +
>> + hws[LOONGSON2_PIX1_PLL] = loongson2_clk_pll_register("pix1_pll",
>> + "ref_100m",
>> + loongson2_pll_base + 0x40);
>> +
>> + hws[LOONGSON2_NODE_CLK] = clk_hw_register_divider(NULL, "node",
>> + "node_pll", 0,
>> + loongson2_pll_base + 0x8, 0,
>> + 6, CLK_DIVIDER_ONE_BASED,
>> + &loongson2_clk_lock);
>> +
>> + /*
>> + * The hda clk divisor in the upper 32bits and the clk-prodiver
>> + * layer code doesn't support 64bit io operation thus a conversion
>> + * is required that subtract shift by 32 and add 4byte to the hda
>> + * address
>> + */
>> + hws[LOONGSON2_HDA_CLK] = clk_hw_register_divider(NULL, "hda",
>> + "ddr_pll", 0,
>> + loongson2_pll_base + 0x22, 12,
>> + 7, CLK_DIVIDER_ONE_BASED,
>> + &loongson2_clk_lock);
>> +
>> + hws[LOONGSON2_GPU_CLK] = clk_hw_register_divider(NULL, "gpu",
>> + "ddr_pll", 0,
>> + loongson2_pll_base + 0x18, 22,
>> + 6, CLK_DIVIDER_ONE_BASED,
>> + &loongson2_clk_lock);
>> +
>> + hws[LOONGSON2_DDR_CLK] = clk_hw_register_divider(NULL, "ddr",
>> + "ddr_pll", 0,
>> + loongson2_pll_base + 0x18, 0,
>> + 6, CLK_DIVIDER_ONE_BASED,
>> + &loongson2_clk_lock);
>> +
>> + hws[LOONGSON2_GMAC_CLK] = clk_hw_register_divider(NULL, "gmac",
>> + "dc_pll", 0,
>> + loongson2_pll_base + 0x28, 22,
>> + 6, CLK_DIVIDER_ONE_BASED,
>> + &loongson2_clk_lock);
>> +
>> + hws[LOONGSON2_DC_CLK] = clk_hw_register_divider(NULL, "dc",
>> + "dc_pll", 0,
>> + loongson2_pll_base + 0x28, 0,
>> + 6, CLK_DIVIDER_ONE_BASED,
>> + &loongson2_clk_lock);
>> +
>> + hws[LOONGSON2_APB_CLK] = loongson2_clk_register(NULL, "apb",
>> + "gmac",
>> + &loongson2_apb_clk_ops, 0);
>> +
>> + hws[LOONGSON2_USB_CLK] = loongson2_clk_register(NULL, "usb",
>> + "gmac",
>> + &loongson2_usb_clk_ops, 0);
>> +
>> + hws[LOONGSON2_SATA_CLK] = loongson2_clk_register(NULL, "sata",
>> + "gmac",
>> + &loongson2_sata_clk_ops, 0);
>> +
>> + hws[LOONGSON2_PIX0_CLK] = clk_hw_register_divider(NULL, "pix0",
>> + "pix0_pll", 0,
>> + loongson2_pll_base + 0x38, 0, 6,
>> + CLK_DIVIDER_ONE_BASED,
>> + &loongson2_clk_lock);
>> +
>> + hws[LOONGSON2_PIX1_CLK] = clk_hw_register_divider(NULL, "pix1",
>> + "pix1_pll", 0,
>> + loongson2_pll_base + 0x48, 0, 6,
>> + CLK_DIVIDER_ONE_BASED,
>> + &loongson2_clk_lock);
>> +
>> + loongson2_check_clk_hws(hws, LOONGSON2_CLK_END);
>> +
>> + of_clk_add_hw_provider(np, of_clk_hw_onecell_get, clk_hw_data);
>> +
>> +err:
>> + iounmap(loongson2_pll_base);
>> +}
>> +
>> +CLK_OF_DECLARE(loongson2_clk, "loongson,ls2k-clk", loongson2_clocks_init);
> Any reason this can't be a platform driver?

For the compatible consideration of other clock controllers of
Loongson-2 series in the future, the way of using dts can be

better compatible.

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