Re: [PATCH V1 2/9] clk: sprd: Add common infrastructure

From: Stephen Boyd
Date: Mon Jun 19 2017 - 21:29:19 EST


On 06/18, Chunyan Zhang wrote:
> Added Spreadtrum's clock driver common structure and registration code.
>
> Signed-off-by: Chunyan Zhang <chunyan.zhang@xxxxxxxxxxxxxx>
> ---
> drivers/clk/Makefile | 1 +
> drivers/clk/sprd/Makefile | 3 ++
> drivers/clk/sprd/ccu_common.c | 78 +++++++++++++++++++++++++++++++++++++
> drivers/clk/sprd/ccu_common.h | 90 +++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 172 insertions(+)
> create mode 100644 drivers/clk/sprd/Makefile
> create mode 100644 drivers/clk/sprd/ccu_common.c
> create mode 100644 drivers/clk/sprd/ccu_common.h
>
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index c19983a..1d62721 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -81,6 +81,7 @@ obj-$(CONFIG_COMMON_CLK_SAMSUNG) += samsung/
> obj-$(CONFIG_ARCH_SIRF) += sirf/
> obj-$(CONFIG_ARCH_SOCFPGA) += socfpga/
> obj-$(CONFIG_PLAT_SPEAR) += spear/
> +obj-$(CONFIG_ARCH_SPRD) += sprd/
> obj-$(CONFIG_ARCH_STI) += st/
> obj-$(CONFIG_ARCH_SUNXI) += sunxi/
> obj-$(CONFIG_ARCH_SUNXI) += sunxi-ng/
> diff --git a/drivers/clk/sprd/Makefile b/drivers/clk/sprd/Makefile
> new file mode 100644
> index 0000000..8f802b2
> --- /dev/null
> +++ b/drivers/clk/sprd/Makefile
> @@ -0,0 +1,3 @@
> +ifneq ($(CONFIG_OF),)
> +obj-y += ccu_common.o
> +endif

I'd prefer a Kconfig for SPRD clk drivers instead of this
CONFIG_OF check. Then we can compile test the sprd code in
configurations that don't have CONFIG_ARCH_SPRD set too.

> diff --git a/drivers/clk/sprd/ccu_common.c b/drivers/clk/sprd/ccu_common.c
> new file mode 100644
> index 0000000..911f4ba
> --- /dev/null
> +++ b/drivers/clk/sprd/ccu_common.c
> @@ -0,0 +1,78 @@
> +/*
> + * Spreadtrum clock infrastructure
> + *
> + * Copyright (C) 2017 Spreadtrum, Inc.
> + *
> + * SPDX-License-Identifier: GPL-2.0
> + */
> +
> +#include "ccu_common.h"
> +
> +static inline void __iomem *ccu_find_base(struct ccu_addr_map *maps,
> + unsigned int num, unsigned int reg)
> +{
> + int i;
> +
> + for (i = 0; i < num; i++)
> + if ((reg & 0xffff0000) == maps[i].phy)

What is this?

> + return maps[i].virt;
> +
> + return 0;
> +}
> +
> +int sprd_ccu_probe(struct device_node *node, struct ccu_addr_map *maps,
> + unsigned int count, const struct sprd_ccu_desc *desc)
> +{
> + int i, ret = 0;
> + struct ccu_common *cclk;
> + struct clk_hw *hw;
> +
> + for (i = 0; i < desc->num_ccu_clks; i++) {
> + cclk = desc->ccu_clks[i];
> + if (!cclk)
> + continue;
> +
> + cclk->base = ccu_find_base(maps, count, cclk->reg);
> + if (!cclk->base) {
> + pr_err("%s: No mapped address found for clock(0x%x)\n",
> + __func__, cclk->reg);
> + return -EINVAL;
> + }
> + cclk->reg = cclk->reg & 0xffff;
> + }
> +
> + for (i = 0; i < desc->hw_clks->num; i++) {
> +
> + hw = desc->hw_clks->hws[i];
> +
> + if (!hw)
> + continue;
> +
> + ret = clk_hw_register(NULL, hw);
> + if (ret) {
> + pr_err("Couldn't register clock %d - %s\n",
> + i, hw->init->name);
> + goto err_clk_unreg;
> + }
> + }
> +
> + ret = of_clk_add_hw_provider(node, of_clk_hw_onecell_get,
> + desc->hw_clks);
> + if (ret) {
> + pr_err("Failed to add clock provider.\n");
> + goto err_clk_unreg;
> + }
> +
> + return 0;
> +
> +err_clk_unreg:
> + while (--i >= 0) {
> + hw = desc->hw_clks->hws[i];
> + if (!hw)
> + continue;
> +
> + clk_hw_unregister(hw);
> + }
> +
> + return ret;
> +}
> diff --git a/drivers/clk/sprd/ccu_common.h b/drivers/clk/sprd/ccu_common.h
> new file mode 100644
> index 0000000..ff07772
> --- /dev/null
> +++ b/drivers/clk/sprd/ccu_common.h
> @@ -0,0 +1,90 @@
> +/*
> + * Spreadtrum clock infrastructure
> + *
> + * Copyright (C) 2017 Spreadtrum, Inc.
> + *
> + * SPDX-License-Identifier: GPL-2.0
> + */
> +
> +#ifndef _CCU_COMMON_H_
> +#define _CCU_COMMON_H_
> +
> +#include <linux/clk-provider.h>
> +
> +struct device_node;
> +
> +#define CLK_HW_INIT_NO_PARENT(_name, _ops, _flags) \
> + (&(struct clk_init_data) { \
> + .flags = _flags, \
> + .name = _name, \
> + .parent_names = NULL, \
> + .num_parents = 0, \
> + .ops = _ops, \
> + })
> +
> +#define CLK_HW_INIT(_name, _parent, _ops, _flags) \
> + (&(struct clk_init_data) { \
> + .flags = _flags, \
> + .name = _name, \
> + .parent_names = (const char *[]) { _parent }, \
> + .num_parents = 1, \
> + .ops = _ops, \
> + })
> +
> +#define CLK_HW_INIT_PARENTS(_name, _parents, _ops, _flags) \
> + (&(struct clk_init_data) { \
> + .flags = _flags, \
> + .name = _name, \
> + .parent_names = _parents, \
> + .num_parents = ARRAY_SIZE(_parents), \
> + .ops = _ops, \
> + })
> +
> +#define CLK_FIXED_FACTOR(_struct, _name, _parent, \
> + _div, _mult, _flags) \
> + struct clk_fixed_factor _struct = { \
> + .div = _div, \
> + .mult = _mult, \
> + .hw.init = CLK_HW_INIT(_name, \
> + _parent, \
> + &clk_fixed_factor_ops, \
> + _flags), \
> + }
> +
> +struct ccu_common {
> + void __iomem *base;
> + u32 reg;
> + spinlock_t *lock;
> + struct clk_hw hw;
> +};
> +
> +struct ccu_addr_map {
> + phys_addr_t phy;
> + void __iomem *virt;
> +};
> +
> +static inline u32 ccu_readl(struct ccu_common *common)
> +{
> + return readl(common->base + common->reg);
> +}
> +
> +static inline void ccu_writel(u32 val, struct ccu_common *common)
> +{
> + writel(val, common->base + common->reg);
> +}
> +
> +static inline struct ccu_common *hw_to_ccu_common(struct clk_hw *hw)
> +{
> + return container_of(hw, struct ccu_common, hw);
> +}
> +
> +struct sprd_ccu_desc {
> + struct ccu_common **ccu_clks;
> + unsigned long num_ccu_clks;
> + struct clk_hw_onecell_data *hw_clks;
> +};
> +
> +int sprd_ccu_probe(struct device_node *node, struct ccu_addr_map *maps,
> + unsigned int count, const struct sprd_ccu_desc *desc);
> +
> +#endif /* _CCU_COMMON_H_ */

Do you call them CCUs internally? I thought CCU was a sunxi
thing, so it may make more sense to call it whatever you call the
clock controller on your hardware.

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