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Message-ID: <31c690a347f858a477bbba9c838984ed.sboyd@kernel.org>
Date: Fri, 10 Feb 2023 15:42:30 -0800
From: Stephen Boyd <sboyd@...nel.org>
To: Huacai Chen <chenhuacai@...nel.org>,
Jianmin Lv <lvjianmin@...ngson.cn>,
Jiaxun Yang <jiaxun.yang@...goat.com>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
Michael Turquette <mturquette@...libre.com>,
Rob Herring <robh+dt@...nel.org>,
WANG Xuerui <kernel@...0n.name>,
Yang Li <yang.lee@...ux.alibaba.com>,
Yinbo Zhu <zhuyinbo@...ngson.cn>, devicetree@...r.kernel.org,
linux-clk@...r.kernel.org, linux-kernel@...r.kernel.org,
loongarch@...ts.linux.dev
Subject: Re: [PATCH v10 2/4] clk: clk-loongson2: add clock controller driver support
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?
>
> 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'
> + 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"
> + Clock Controller can generates and supplies clock to various
Same capitalization comment.
> + 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@...ngson.cn>
> + * Copyright (C) 2022-2023 Loongson Technology Corporation Limited
> + */
> +
> +#include <linux/clkdev.h>
Drop include that isn't used.
> +#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.
> +
> + 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.
> +
> + 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.
> +
> + 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?
> +
> + 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.
> +
> + 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.
> +{
> + 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.
> +}
> +
> +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.
> +}
> +
> +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?
> + }
> +
> + 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?
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