Re: [PATCH v3 4/5] clk: mediatek: Add USB clock support in MT8173 APMIXEDSYS

From: Daniel Kurtz
Date: Mon Jul 13 2015 - 10:46:48 EST


Hi James,


On Fri, Jul 10, 2015 at 6:00 PM, James Liao <jamesjj.liao@xxxxxxxxxxxx> wrote:
> Add REF2USB_TX clock support into MT8173 APMIXEDSYS. This clock
> is needed by USB 3.0.
>
> Signed-off-by: James Liao <jamesjj.liao@xxxxxxxxxxxx>
> ---
> drivers/clk/mediatek/clk-mt8173.c | 143 +++++++++++++++++++++++++++++++++
> drivers/clk/mediatek/clk-pll.c | 7 +-
> include/dt-bindings/clock/mt8173-clk.h | 3 +-
> 3 files changed, 146 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/clk/mediatek/clk-mt8173.c b/drivers/clk/mediatek/clk-mt8173.c
> index 1d21e26..11f82cb 100644
> --- a/drivers/clk/mediatek/clk-mt8173.c
> +++ b/drivers/clk/mediatek/clk-mt8173.c
> @@ -12,6 +12,7 @@
> * GNU General Public License for more details.
> */
>
> +#include <linux/delay.h>
> #include <linux/of.h>
> #include <linux/of_address.h>
> #include <linux/slab.h>
> @@ -968,6 +969,141 @@ static void __init mtk_pericfg_init(struct device_node *node)
> }
> CLK_OF_DECLARE(mtk_pericfg, "mediatek,mt8173-pericfg", mtk_pericfg_init);
>
> +#define REF2USB_TX_EN BIT(0)
> +#define REF2USB_TX_LPF_EN BIT(1)
> +#define REF2USB_TX_OUT_EN BIT(2)
> +#define REF2USB_EN_MASK (REF2USB_TX_EN | REF2USB_TX_LPF_EN | \
> + REF2USB_TX_OUT_EN)
> +
> +struct mtk_ref2usb_tx {
> + struct clk_hw hw;
> + void __iomem *base_addr;
> +};
> +
> +static inline struct mtk_ref2usb_tx *to_mtk_ref2usb_tx(struct clk_hw *hw)
> +{
> + return container_of(hw, struct mtk_ref2usb_tx, hw);
> +}
> +
> +static int mtk_ref2usb_tx_is_prepared(struct clk_hw *hw)
> +{
> + struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);
> +
> + return (readl(tx->base_addr) & REF2USB_EN_MASK) == REF2USB_EN_MASK;
> +}
> +
> +static int mtk_ref2usb_tx_prepare(struct clk_hw *hw)
> +{
> + struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);
> + u32 val;
> +
> + val = readl(tx->base_addr);
> +
> + val |= REF2USB_TX_EN;
> + writel(val, tx->base_addr);
> + udelay(100);
> +
> + val |= REF2USB_TX_LPF_EN;
> + writel(val, tx->base_addr);
> +
> + val |= REF2USB_TX_OUT_EN;
> + writel(val, tx->base_addr);
> +
> + return 0;
> +}
> +
> +static void mtk_ref2usb_tx_unprepare(struct clk_hw *hw)
> +{
> + struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);
> + u32 val;
> +
> + val = readl(tx->base_addr);
> + val &= ~REF2USB_EN_MASK;
> + writel(val, tx->base_addr);
> +}
> +
> +static const struct clk_ops mtk_ref2usb_tx_ops = {
> + .is_prepared = mtk_ref2usb_tx_is_prepared,
> + .prepare = mtk_ref2usb_tx_prepare,
> + .unprepare = mtk_ref2usb_tx_unprepare,
> +};

Burying the implementation of this special "mtk_ref2usb" clock in
clk-mt8173,c seems a bit awkward.
Can you please move it to its own file, like mediatek/clk-usb.c?


> +
> +static struct clk *mtk_clk_register_ref2usb_tx(const char *name,
> + const char *parent_name, void __iomem *reg)
> +{
> + struct mtk_ref2usb_tx *tx;
> + struct clk_init_data init = {};
> + struct clk *clk;
> +
> + tx = kzalloc(sizeof(*tx), GFP_KERNEL);
> + if (!tx)
> + return ERR_PTR(-ENOMEM);
> +
> + tx->base_addr = reg;
> + tx->hw.init = &init;
> +
> + init.name = name;
> + init.ops = &mtk_ref2usb_tx_ops;
> + init.parent_names = &parent_name;
> + init.num_parents = 1;
> +
> + clk = clk_register(NULL, &tx->hw);
> +
> + if (IS_ERR(clk)) {
> + pr_err("Failed to register clk %s: %ld\n", name, PTR_ERR(clk));
> + kfree(tx);
> + }
> +
> + return clk;
> +}
> +
> +struct mtk_apmixed_ex {
> + int id;
> + const char *name;
> + const char *parent;
> + u32 reg_ofs;
> +};
> +
> +#define APMIXED_EX(_id, _name, _parent, _reg_ofs) { \
> + .id = _id, \
> + .name = _name, \
> + .parent = _parent, \
> + .reg_ofs = _reg_ofs, \
> + }
> +
> +static const struct mtk_apmixed_ex apmixed_ex[] = {

__initconst

> + APMIXED_EX(CLK_APMIXED_REF2USB_TX, "ref2usb_tx", "clk26m", 0x8),
> +};
> +
> +static void __init mtk_clk_register_apmixedsys_special(struct device_node *node,
> + struct clk_onecell_data *clk_data)
> +{
> + void __iomem *base;
> + struct clk *clk;
> + int i;
> +
> + base = of_iomap(node, 0);
> + if (!base) {
> + pr_err("%s(): ioremap failed\n", __func__);
> + return;
> + }
> +
> + for (i = 0; i < ARRAY_SIZE(apmixed_ex); i++) {
> + const struct mtk_apmixed_ex *ape = &apmixed_ex[i];
> +
> + clk = mtk_clk_register_ref2usb_tx(ape->name, ape->parent,
> + base + ape->reg_ofs);
> +
> + if (IS_ERR(clk)) {
> + pr_err("Failed to register clk %s: %ld\n", ape->name,
> + PTR_ERR(clk));
> + continue;
> + }
> +
> + clk_data->clks[CLK_APMIXED_REF2USB_TX] = clk;

This works assuming ARRAY_SIZE(apmixed_ex) == 1.
Either remove the loop since it is unnecessary, or do:
clk_data->clks[ape->id] = clk;

> + }
> +}
> +
> #define MT8173_PLL_FMAX (3000UL * MHZ)
>
> #define CON0_MT8173_RST_BAR BIT(24)
> @@ -1010,12 +1146,19 @@ static const struct mtk_pll_data plls[] = {
> static void __init mtk_apmixedsys_init(struct device_node *node)
> {
> struct clk_onecell_data *clk_data;
> + int r;
>
> mt8173_pll_clk_data = clk_data = mtk_alloc_clk_data(CLK_APMIXED_NR_CLK);
> if (!clk_data)
> return;
>
> mtk_clk_register_plls(node, plls, ARRAY_SIZE(plls), clk_data);
> + mtk_clk_register_apmixedsys_special(node, clk_data);
> +
> + r = of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
> + if (r)
> + pr_err("%s(): could not register clock provider: %d\n",
> + __func__, r);
>
> mtk_clk_enable_critical();
> }
> diff --git a/drivers/clk/mediatek/clk-pll.c b/drivers/clk/mediatek/clk-pll.c
> index 44409e9..813f0c7 100644
> --- a/drivers/clk/mediatek/clk-pll.c
> +++ b/drivers/clk/mediatek/clk-pll.c
> @@ -302,7 +302,7 @@ void __init mtk_clk_register_plls(struct device_node *node,
> const struct mtk_pll_data *plls, int num_plls, struct clk_onecell_data *clk_data)
> {
> void __iomem *base;
> - int r, i;
> + int i;
> struct clk *clk;
>
> base = of_iomap(node, 0);
> @@ -324,9 +324,4 @@ void __init mtk_clk_register_plls(struct device_node *node,
>
> clk_data->clks[pll->id] = clk;
> }
> -
> - r = of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
> - if (r)
> - pr_err("%s(): could not register clock provider: %d\n",
> - __func__, r);
> }
> diff --git a/include/dt-bindings/clock/mt8173-clk.h b/include/dt-bindings/clock/mt8173-clk.h
> index 6ce88bf..7b7c555 100644
> --- a/include/dt-bindings/clock/mt8173-clk.h
> +++ b/include/dt-bindings/clock/mt8173-clk.h
> @@ -172,7 +172,8 @@
> #define CLK_APMIXED_APLL2 12
> #define CLK_APMIXED_LVDSPLL 13
> #define CLK_APMIXED_MSDCPLL2 14
> -#define CLK_APMIXED_NR_CLK 15
> +#define CLK_APMIXED_REF2USB_TX 15
> +#define CLK_APMIXED_NR_CLK 16
>
> /* INFRA_SYS */
>
> --
> 1.8.1.1.dirty
>
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