Hi Hans,
2014/1/10 Hans de Goede <hdego...@redhat.com>:
> The usb-clk register is special in that it not only contains clk gate bits,
> but also has a few reset bits. This commit adds support for this by allowing
> gates type sunxi clks to also register a reset controller.
>
> Signed-off-by: Hans de Goede <hdego...@redhat.com>
> ---
> drivers/clk/sunxi/clk-sunxi.c | 71
> +++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 71 insertions(+)
>
> diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
> index 03bb8b8..b5d0a7a 100644
> --- a/drivers/clk/sunxi/clk-sunxi.c
> +++ b/drivers/clk/sunxi/clk-sunxi.c
> @@ -18,6 +18,7 @@
> #include <linux/clkdev.h>
> #include <linux/of.h>
> #include <linux/of_address.h>
> +#include <linux/reset-controller.h>
>
> #include "clk-factors.h"
>
> @@ -741,6 +742,59 @@ static void __init sunxi_divider_clk_setup(struct
> device_node *node,
>
>
> /**
> + * gates_reset... - reset bits in leaf gate clk registers handling
> + */
> +
> +struct gates_reset_data {
> + void __iomem *reg;
> + spinlock_t *lock;
> + struct reset_controller_dev rcdev;
> +};
> +
> +static int gates_reset_assert(struct reset_controller_dev *rcdev,
> + unsigned long id)
They're static, so it's not a big deal, but I think these two should
have a prefix (sunxi_) like the rest of the functions.
> +{
> + struct gates_reset_data *data = container_of(rcdev,
> + struct gates_reset_data,
> + rcdev);
> + unsigned long flags;
> + u32 reg;
> +
> + spin_lock_irqsave(data->lock, flags);
> +
> + reg = readl(data->reg);
> + writel(reg & ~BIT(id), data->reg);
> +
> + spin_unlock_irqrestore(data->lock, flags);
> +
> + return 0;
> +}
> +
> +static int gates_reset_deassert(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + struct gates_reset_data *data = container_of(rcdev,
> + struct gates_reset_data,
> + rcdev);
> + unsigned long flags;
> + u32 reg;
> +
> + spin_lock_irqsave(data->lock, flags);
> +
> + reg = readl(data->reg);
> + writel(reg | BIT(id), data->reg);
> +
> + spin_unlock_irqrestore(data->lock, flags);
> +
> + return 0;
> +}
> +
> +static struct reset_control_ops gates_reset_ops = {
> + .assert = gates_reset_assert,
> + .deassert = gates_reset_deassert,
> +};
> +
> +/**
> * sunxi_gates_clk_setup() - Setup function for leaf gates on clocks
> */
>
> @@ -748,6 +802,7 @@ static void __init sunxi_divider_clk_setup(struct
> device_node *node,
>
> struct gates_data {
> DECLARE_BITMAP(mask, SUNXI_GATES_MAX_SIZE);
> + u32 reset_mask;
> };
>
> static const struct gates_data sun4i_axi_gates_data __initconst = {
> @@ -818,6 +873,7 @@ static void __init sunxi_gates_clk_setup(struct
> device_node *node,
> struct gates_data *data)
> {
> struct clk_onecell_data *clk_data;
> + struct gates_reset_data *reset_data;
> const char *clk_parent;
> const char *clk_name;
> void *reg;
> @@ -861,6 +917,21 @@ static void __init sunxi_gates_clk_setup(struct
> device_node *node,
> clk_data->clk_num = i;
>
> of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
> +
> + /* Register a reset controler for gates with reset bits */
> + if (data->reset_mask == 0)
> + return;
> +
> + reset_data = kzalloc(sizeof(*reset_data), GFP_KERNEL);
> + if (!reset_data)
> + return;
> +
> + reset_data->reg = reg;
> + reset_data->lock = &clk_lock;
> + reset_data->rcdev.nr_resets = __fls(data->reset_mask) + 1;
Maybe something like hweight32() would be a better fit here. fls would
only work if the reset bits are on the end.
> + reset_data->rcdev.ops = &gates_reset_ops;
> + reset_data->rcdev.of_node = node;
> + reset_controller_register(&reset_data->rcdev);
> }
Cheers,
Emilio
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