Re: [PATCH 2/2] clk: aspeed: Setup video engine clocking

[Joel Stanley <joel@jms.id.au>]

Hi Eddie,

On Wed, 12 Dec 2018 at 06:42, Eddie James <eajames@linux.ibm.com> wrote:
>
> Add the video engine reset bit. Add eclk mux and clock divider table.
>
> Signed-off-by: Eddie James <eajames@linux.ibm.com>
> Acked-by: Stephen Boyd <sboyd@kernel.org>
> ---
>  drivers/clk/clk-aspeed.c | 41 +++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 39 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/clk/clk-aspeed.c b/drivers/clk/clk-aspeed.c
> index 5961367..f16ce7d 100644
> --- a/drivers/clk/clk-aspeed.c
> +++ b/drivers/clk/clk-aspeed.c
> @@ -87,7 +87,7 @@ struct aspeed_clk_gate {
>  /* TODO: ask Aspeed about the actual parent data */
>  static const struct aspeed_gate_data aspeed_gates[] = {
>         /*                               clk rst   name                 parent  flags */
> -       [ASPEED_CLK_GATE_ECLK] =        {  0, -1, "eclk-gate",          "eclk", 0 }, /* Video Engine */
> +       [ASPEED_CLK_GATE_ECLK] =        {  0,  6, "eclk-gate",          "eclk", 0 }, /* Video Engine */


>         [ASPEED_CLK_GATE_GCLK] =        {  1,  7, "gclk-gate",          NULL,   0 }, /* 2D engine */
>         [ASPEED_CLK_GATE_MCLK] =        {  2, -1, "mclk-gate",          "mpll", CLK_IS_CRITICAL }, /* SDRAM */
>         [ASPEED_CLK_GATE_VCLK] =        {  3,  6, "vclk-gate",          NULL,   0 }, /* Video Capture */
> @@ -113,6 +113,24 @@ struct aspeed_clk_gate {
>         [ASPEED_CLK_GATE_LHCCLK] =      { 28, -1, "lhclk-gate",         "lhclk", 0 }, /* LPC master/LPC+ */
>  };
>
> +static const char * const eclk_parent_names[] = {
> +       "mpll",

Is the mpll really an input to the eclk?

> +       "hpll",
> +       "dpll",

We don't have a dpll in the driver that I can see.

> +};
> +
> +static const struct clk_div_table ast2500_eclk_div_table[] = {

Is the clocking setup different on the ast2400?

> +       { 0x0, 2 },
> +       { 0x1, 2 },
> +       { 0x2, 3 },
> +       { 0x3, 4 },
> +       { 0x4, 5 },
> +       { 0x5, 6 },
> +       { 0x6, 7 },
> +       { 0x7, 8 },
> +       { 0 }
> +};

> @@ -317,6 +338,7 @@ struct aspeed_reset {
>         [ASPEED_RESET_PECI]     = 10,
>         [ASPEED_RESET_I2C]      =  2,
>         [ASPEED_RESET_AHB]      =  1,
> +       [ASPEED_RESET_VIDEO]    =  6,

You've added the reset line to the ASPEED_CLK_GATE_ECLK clock so you
do not need to separately expose the reset controller. Instead
enabling the clock will deassert the rest line for you.

This means you should drop the change from the header too, and it
affects the bindings document for the video engine.

>
>         /*
>          * SCUD4 resets start at an offset to separate them from
> @@ -522,6 +544,22 @@ static int aspeed_clk_probe(struct platform_device *pdev)
>                 return PTR_ERR(hw);
>         aspeed_clk_data->hws[ASPEED_CLK_24M] = hw;
>
> +       hw = clk_hw_register_mux(dev, "eclk-mux", eclk_parent_names,
> +                                ARRAY_SIZE(eclk_parent_names), 0,
> +                                scu_base + ASPEED_CLK_SELECTION, 2, 0x3, 0,
> +                                &aspeed_clk_lock);
> +       if (IS_ERR(hw))
> +               return PTR_ERR(hw);
> +       aspeed_clk_data->hws[ASPEED_CLK_ECLK_MUX] = hw;
> +
> +       hw = clk_hw_register_divider_table(dev, "eclk", "eclk-mux", 0,
> +                                          scu_base + ASPEED_CLK_SELECTION, 28,
> +                                          3, 0, soc_data->eclk_div_table,
> +                                          &aspeed_clk_lock);
> +       if (IS_ERR(hw))
> +               return PTR_ERR(hw);
> +       aspeed_clk_data->hws[ASPEED_CLK_ECLK] = hw;
> +
>         /*
>          * TODO: There are a number of clocks that not included in this driver
>          * as more information is required:
> @@ -531,7 +569,6 @@ static int aspeed_clk_probe(struct platform_device *pdev)
>          *   RGMII
>          *   RMII
>          *   UART[1..5] clock source mux
> -        *   Video Engine (ECLK) mux and clock divider
>          */
>
>         for (i = 0; i < ARRAY_SIZE(aspeed_gates); i++) {
> --
> 1.8.3.1
>