Re: [PATCH v10 2/4] clk: clk-loongson2: add clock controller driver support
From: zhuyinbo
Date: Wed Feb 15 2023 - 02:35:32 EST
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@xxxxxxxxxxx>
+ * 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.