Subject: [PATCH v2 1/7] clk: sunxi: Add support for AXI, AHB, APB0 and APB1 gates

From: [email-masked] (Mike Turquette)
Date: Wed, 03 Apr 2013 19:46:58 -0700

Quoting Emilio L?pez (2013-04-03 18:19:22)
> Hi Mike,
> 
> El 03/04/13 18:48, Mike Turquette escribi?:
> > Quoting Emilio L?pez (2013-03-27 14:20:37)
> >> diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
> >> index d528a24..244de90 100644
> >> --- a/drivers/clk/sunxi/clk-sunxi.c
> >> +++ b/drivers/clk/sunxi/clk-sunxi.c
> >> @@ -302,6 +302,82 @@ static void __init sunxi_divider_clk_setup(struct device_node *node,
> >>  }
> >>  
> >>  
> >> +
> > 
> > A lot of white space between these functions.
> 
> All of the function blocks are separated with three spaces on the file;
> I thought it looked more readable that way, but I don't have any strong
> opinion on separation. Is there any standard for this used on the kernel?
> 
> In any case, and to keep consistency, can we handle this on a follow-up
> patch?
> 

If it's consistent throughout the file then go ahead and keep it.

> >> +/**
> >> + * sunxi_gates_clk_setup() - Setup function for leaf gates on clocks
> >> + */
> >> +
> >> +#define SUNXI_GATES_MAX_SIZE   64
> >> +
> >> +struct gates_data {
> >> +       DECLARE_BITMAP(mask, SUNXI_GATES_MAX_SIZE);
> >> +};
> >> +
> >> +static const __initconst struct gates_data axi_gates_data = {
> >> +       .mask = {1},
> >> +};
> >> +
> >> +static const __initconst struct gates_data ahb_gates_data = {
> >> +       .mask = {0x7F77FFF, 0x14FB3F},
> >> +};
> >> +
> >> +static const __initconst struct gates_data apb0_gates_data = {
> >> +       .mask = {0x4EF},
> >> +};
> >> +
> >> +static const __initconst struct gates_data apb1_gates_data = {
> >> +       .mask = {0xFF00F7},
> >> +};
> >> +
> >> +static void __init sunxi_gates_clk_setup(struct device_node *node,
> >> +                                        struct gates_data *data)
> >> +{
> >> +       struct clk_onecell_data *clk_data;
> >> +       const char *clk_parent;
> >> +       const char *clk_name;
> >> +       void *reg;
> >> +       int qty;
> >> +       int i = 0;
> >> +       int j = 0;
> >> +       int ignore;
> >> +
> >> +       reg = of_iomap(node, 0);
> >> +
> >> +       clk_parent = of_clk_get_parent_name(node, 0);
> >> +
> >> +       /* Worst-case size approximation and memory allocation */
> >> +       qty = find_last_bit(data->mask, SUNXI_GATES_MAX_SIZE);
> >> +       clk_data = kmalloc(sizeof(struct clk_onecell_data), GFP_KERNEL);
> >> +       if (!clk_data)
> >> +               return;
> >> +       clk_data->clks = kzalloc((qty+1) * sizeof(struct clk *), GFP_KERNEL);
> >> +       if (!clk_data->clks) {
> >> +               kfree(clk_data);
> >> +               return;
> >> +       }
> >> +
> >> +       for_each_set_bit(i, data->mask, SUNXI_GATES_MAX_SIZE) {
> >> +               of_property_read_string_index(node, "clock-output-names",
> >> +                                             j, &clk_name);
> >> +
> >> +               /* No driver claims this clock, but it should remain gated */
> > 
> > Should the comment read, "ungated" instead of "gated"?
> 
> Indeed, good catch. Do you want me to resend the series, or can you
> amend this when picking the patches?
> 

I can amend it, but I don't like to get into the habit of doing that too
often.

I'll wait on Gregory's response on the of_clk_init stuff before I do so.

Regards,
Mike

> >> +               ignore = !strcmp("ahb_sdram", clk_name) ? CLK_IGNORE_UNUSED : 0;
> >> +
> >> +               clk_data->clks[i] = clk_register_gate(NULL, clk_name,
> >> +                                                     clk_parent, ignore,
> >> +                                                     reg + 4 * (i/32), i % 32,
> >> +                                                     0, &clk_lock);
> >> +               WARN_ON(IS_ERR(clk_data->clks[i]));
> >> +
> >> +               j++;
> >> +       }
> >> +
> >> +       /* Adjust to the real max */
> >> +       clk_data->clk_num = i;
> >> +
> >> +       of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
> >> +}
> >> +
> >>  /* Matches for of_clk_init */
> >>  static const __initconst struct of_device_id clk_match[] = {
> >>         {.compatible = "fixed-clock", .data = of_fixed_clk_setup,},
> >> @@ -331,6 +407,15 @@ static const __initconst struct of_device_id clk_mux_match[] = {
> >>         {}
> >>  };
> >>  
> >> +/* Matches for gate clocks */
> >> +static const __initconst struct of_device_id clk_gates_match[] = {
> >> +       {.compatible = "allwinner,sun4i-axi-gates-clk", .data = &axi_gates_data,},
> >> +       {.compatible = "allwinner,sun4i-ahb-gates-clk", .data = &ahb_gates_data,},
> >> +       {.compatible = "allwinner,sun4i-apb0-gates-clk", .data = &apb0_gates_data,},
> >> +       {.compatible = "allwinner,sun4i-apb1-gates-clk", .data = &apb1_gates_data,},
> >> +       {}
> >> +};
> >> +
> >>  static void __init of_sunxi_table_clock_setup(const struct of_device_id *clk_match,
> >>                                               void *function)
> >>  {
> >> @@ -359,4 +444,7 @@ void __init sunxi_init_clocks(void)
> >>  
> >>         /* Register mux clocks */
> >>         of_sunxi_table_clock_setup(clk_mux_match, sunxi_mux_clk_setup);
> >> +
> >> +       /* Register gate clocks */
> >> +       of_sunxi_table_clock_setup(clk_gates_match, sunxi_gates_clk_setup);
> > 
> > I'm still a device tree noob, so this may be a dumb question.  Can the
> > above be converted to of_clk_init?
> 
> As far as I know, you can't, because of_clk_init doesn't allow for
> custom data to be passed to the functions. If we were to use of_clk_init
> we would need one function per clock, and it would be mostly duplicated
> code / wrappers. I've added Gregory on Cc, please correct me if this is
> not the case.
> 
> Thanks for the review,
> 
> Emilio