[PATCH 2/5] clk: bcm2835: enable management of PCM clock

Geert Uytterhoeven
2016-01-10T18:56:20Z

Hi Martin,

On Sun, Jan 10, 2016 at 7:01 PM, Martin Sperl <kernel@martin.sperl.org> wrote:
>> On 10.01.2016, at 14:02, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>> I wrote:
>> | Hence it can better be replaced (it seems to be unused in dts files, but you
>> | can keep the definition to be 100% sure) by an ARRAY_SIZE() in the C driver.
>> | This requires changing the driver to e.g. initialize clks[] in
>> |bcm2835_clk_probe() based on a table instead of explicit code.
>>
>> If you fill in clks[] from a static table, you can take ARRAY_SIZE of
>> the static table.
>
> You mean something like the below?
> (note: copy/paste from console issues - spaces instead of tabs)

More or less.

> diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
> index dee67b3..5ce5e7f 100644
> --- a/drivers/clk/bcm/clk-bcm2835.c
> +++ b/drivers/clk/bcm/clk-bcm2835.c
> @@ -294,7 +294,7 @@ struct bcm2835_cprman {
> const char *osc_name;
>
> struct clk_onecell_data onecell;
> - struct clk *clks[BCM2835_CLOCK_COUNT];
> + struct clk *clks[];

If all clocks would be in a single array, you could get rid of the extra
dynamic allocation, and still use

struct clk *clks[ARRAY_SIZE(all_clocks_array)];

here.

> };
>
> static inline void cprman_write(struct bcm2835_cprman *cprman, u32 reg, u32 val
> @@ -496,6 +496,14 @@ static const struct bcm2835_pll_data bcm2835_pllh_data = {
> .max_fb_rate = BCM2835_MAX_FB_RATE,
> };
>
> +static const struct bcm2835_pll_data *bcm2835_plls[] = {
> + [BCM2835_PLLA] = &bcm2835_plla_data,
> + [BCM2835_PLLB] = &bcm2835_pllb_data,
> + [BCM2835_PLLC] = &bcm2835_pllc_data,
> + [BCM2835_PLLD] = &bcm2835_plld_data,
> + [BCM2835_PLLH] = &bcm2835_pllh_data,
> +};

This is a sparse array?

> +
> struct bcm2835_pll_divider_data {
> const char *name;
> const struct bcm2835_pll_data *source_pll;
> @@ -625,6 +633,20 @@ static const struct bcm2835_pll_divider_data bcm2835_pllh_p
> .fixed_divider = 10,
> };
>
> +static const struct bcm2835_pll_divider_data *bcm2835_pll_divs[] = {
> + [BCM2835_PLLA_CORE] = &bcm2835_plla_core_data,
> + [BCM2835_PLLA_PER] = &bcm2835_plla_per_data,
> + [BCM2835_PLLC_CORE0] = &bcm2835_pllc_core0_data,
> + [BCM2835_PLLC_CORE1] = &bcm2835_pllc_core1_data,
> + [BCM2835_PLLC_CORE2] = &bcm2835_pllc_core2_data,
> + [BCM2835_PLLC_PER] = &bcm2835_pllc_per_data,
> + [BCM2835_PLLD_CORE] = &bcm2835_plld_core_data,
> + [BCM2835_PLLD_PER] = &bcm2835_plld_per_data,
> + [BCM2835_PLLH_RCAL] = &bcm2835_pllh_rcal_data,
> + [BCM2835_PLLH_AUX] = &bcm2835_pllh_aux_data,
> + [BCM2835_PLLH_PIX] = &bcm2835_pllh_pix_data,
> +};

Likewise.

> struct bcm2835_clock_data {
> const char *name;
>
> @@ -837,6 +859,24 @@ static const struct bcm2835_clock_data bcm2835_clock_pcm_da
> .mash = 1,
> };
>
> +static const struct bcm2835_clock_data *bcm2835_clks[] = {
> + [BCM2835_CLOCK_TIMER] = &bcm2835_clock_timer_data,
> + [BCM2835_CLOCK_OTP] = &bcm2835_clock_otp_data,
> + [BCM2835_CLOCK_TSENS] = &bcm2835_clock_tsens_data,
> + [BCM2835_CLOCK_VPU] = &bcm2835_clock_vpu_data,
> + [BCM2835_CLOCK_V3D] = &bcm2835_clock_v3d_data,
> + [BCM2835_CLOCK_ISP] = &bcm2835_clock_isp_data,
> + [BCM2835_CLOCK_H264] = &bcm2835_clock_h264_data,
> + [BCM2835_CLOCK_V3D] = &bcm2835_clock_v3d_data,
> + [BCM2835_CLOCK_SDRAM] = &bcm2835_clock_sdram_data,
> + [BCM2835_CLOCK_UART] = &bcm2835_clock_uart_data,
> + [BCM2835_CLOCK_VEC] = &bcm2835_clock_vec_data,
> + [BCM2835_CLOCK_HSM] = &bcm2835_clock_hsm_data,
> + [BCM2835_CLOCK_EMMC] = &bcm2835_clock_emmc_data,
> + [BCM2835_CLOCK_PWM] = &bcm2835_clock_pwm_data,
> + [BCM2835_CLOCK_PCM] = &bcm2835_clock_pcm_data,
> +};

Likewise.

> struct bcm2835_pll {
> struct clk_hw hw;
> struct bcm2835_cprman *cprman;
> @@ -1560,8 +1600,13 @@ static int bcm2835_clk_probe(struct platform_device *pdev)
> struct clk **clks;
> struct bcm2835_cprman *cprman;
> struct resource *res;
> + const int clks_cnt = max(ARRAY_SIZE(bcm2835_plls),
> + max(ARRAY_SIZE(bcm2835_pll_divs),
> + ARRAY_SIZE(bcm2835_clks))) + 1;
> + size_t alloc = sizeof(*cprman) + clks_cnt * sizeof(*clks);
> + size_t i;

If you combine all 3 arrays in a single non-sparse array, you could get rid
of the dynamic allocation using the maximum of the 3 sizes, and can just
use a single ARRAY_SIZE().

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds