Re: [PATCH v10 2/4] clk: clk-loongson2: add clock controller driver support

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在 2022/11/30 21:14, XiaochuanMao 写道:
hi yinbo

On 2022/11/29 11:41, Yinbo Zhu wrote:
This driver provides support for clock controller on Loongson-2 SoC,
the Loongson-2 SoC uses a 100MHz clock as the PLL reference clock,
there are five independent PLLs inside, each of which PLL can
provide up to three sets of frequency dependent clock outputs.

Signed-off-by: Yinbo Zhu <zhuyinbo@xxxxxxxxxxx>
---
Change in v10:
        1. Detach of_clk_init to another patch.
Change in v9:
        1. Add all history changelog information.
Change in v8:
        1. Remove the flag "CLK_IS_BASIC".
Change in v7:
        1. Adjust position alphabetically in Kconfig and Makefile.
        2. Add static for loongson2_pll_base.
        3. Move other file-scope variables in probe.
Change in v6:
        1. NO change, but other patch in this series of patches has
           changes.
Change in v5:
        1. Replace loongson2 with Loongson-2 in commit info.
        2. Replace Loongson2 with Loongson-2 in binding and
           Kconfig file.
        3. Replace soc with SoC.
Change in v4:
        1. Fixup clock-names that replace "xxx-clk" with "xxx".
Change in v3:
        1. NO change, but other patch in this series of patches has
           changes.
Change in v2:
        1. Update the include filename.
        2. Change string from refclk/REFCLK to ref/REF.

  MAINTAINERS                 |   1 +
  arch/loongarch/Kconfig      |   1 +
  drivers/clk/Kconfig         |   9 ++
  drivers/clk/Makefile        |   1 +
  drivers/clk/clk-loongson2.c | 286 ++++++++++++++++++++++++++++++++++++
  5 files changed, 298 insertions(+)
  create mode 100644 drivers/clk/clk-loongson2.c

diff --git a/MAINTAINERS b/MAINTAINERS
index ab94893fe2f6..73fa56f1fd5d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12025,6 +12025,7 @@ LOONGSON-2 SOC SERIES CLOCK DRIVER
  M:    Yinbo Zhu <zhuyinbo@xxxxxxxxxxx>
  L:    linux-clk@xxxxxxxxxxxxxxx
  S:    Maintained
+F:    drivers/clk/clk-loongson2.c
  F:    include/dt-bindings/clock/loongson,ls2k-clk.h
    LSILOGIC MPT FUSION DRIVERS (FC/SAS/SPI)
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
    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
+      Common Clock Framework Controller (CCF) on Loongson-2 SoC. The
+      Clock Controller can generates and supplies clock to various
+      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/Makefile b/drivers/clk/Makefile
index e3ca0d058a25..b298c5dabc1a 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -43,6 +43,7 @@ obj-$(CONFIG_COMMON_CLK_K210)        += clk-k210.o
  obj-$(CONFIG_LMK04832)            += clk-lmk04832.o
  obj-$(CONFIG_COMMON_CLK_LAN966X)    += clk-lan966x.o
  obj-$(CONFIG_COMMON_CLK_LOCHNAGAR)    += clk-lochnagar.o
+obj-$(CONFIG_COMMON_CLK_LOONGSON2)    += clk-loongson2.o
  obj-$(CONFIG_COMMON_CLK_MAX77686)    += clk-max77686.o
  obj-$(CONFIG_COMMON_CLK_MAX9485)    += clk-max9485.o
  obj-$(CONFIG_ARCH_MILBEAUT_M10V)    += clk-milbeaut.o
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@xxxxxxxxxxx>
+ * Copyright (C) 2022-2023 Loongson Technology Corporation Limited
+ */
+
+#include <linux/clkdev.h>
+#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);
+
+    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));
+
+    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));
+
+    mult = (val >> LOONGSON2_USB_FREQSCALE_SHIFT) &
+            clk_div_mask(LOONGSON2_USB_FREQSCALE_WIDTH);
+
+    rate = parent_rate * (mult + 1);
+    do_div(rate, 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));
+
+    mult = (val >> LOONGSON2_SATA_FREQSCALE_SHIFT) &
+            clk_div_mask(LOONGSON2_SATA_FREQSCALE_WIDTH);
+
+    rate = parent_rate * (mult + 1);
+    do_div(rate, 8);
+
+    return rate;
+}
+

loongson2_sata_recalc_rate, loongson2_usb_recalc_rate,loongson2_apb_recalc_rate are have the same calcuate logic code, only the shift and width are different, I thought it would be possible to abstract out a common function to reduce duplicate code

Thansk your advice, they are base on the same logic, I have noticed this at the begining,

 but I don't abstract it because the parameter of recalc_rate is fixed, and no other parameter

can be passed into it.


in fact, at the v1 version, I wanted to use a common interface to replace the logic of specific

implemetion,but the calculation of this clock was not standard, so I had to do this.


+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)
+{
+    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]));
+}
+
+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);
+}
+
+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;
+    }
+
+    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);




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