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Date: Tue, 25 Jul 2023 19:50:56 +0300
From: Laurent Pinchart <laurent.pinchart@...asonboard.com>
To: Tomi Valkeinen <tomi.valkeinen@...asonboard.com>
Cc: Mauro Carvalho Chehab <mchehab@...nel.org>,
Luca Ceresoli <luca.ceresoli@...tlin.com>,
Andy Shevchenko <andriy.shevchenko@...el.com>,
Sakari Ailus <sakari.ailus@...ux.intel.com>,
Hans Verkuil <hverkuil@...all.nl>,
Satish Nagireddy <satish.nagireddy@...cruise.com>,
Matti Vaittinen <mazziesaccount@...il.com>,
linux-media@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 6/8] media: i2c: ds90ub953: Restructure clkout
management
Hi Tomi,
Thank you for the patch.
On Thu, Jul 20, 2023 at 01:30:37PM +0300, Tomi Valkeinen wrote:
> Separate clkout calculations and register writes into two functions:
> ub953_calc_clkout_params and ub953_write_clkout_regs, and add a struct
> ub953_clkout_data that is used to store the clkout parameters.
>
> This simplifies the clkout management.
>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@...asonboard.com>
> ---
> drivers/media/i2c/ds90ub953.c | 135 ++++++++++++++++++++++--------------------
> 1 file changed, 70 insertions(+), 65 deletions(-)
>
> diff --git a/drivers/media/i2c/ds90ub953.c b/drivers/media/i2c/ds90ub953.c
> index ad479923d2b4..3a19c6dedd2f 100644
> --- a/drivers/media/i2c/ds90ub953.c
> +++ b/drivers/media/i2c/ds90ub953.c
> @@ -131,6 +131,13 @@ struct ub953_hw_data {
> bool is_ub971;
> };
>
> +struct ub953_clkout_data {
> + u32 hs_div;
> + u32 m;
> + u32 n;
> + unsigned long rate;
> +};
> +
> struct ub953_data {
> const struct ub953_hw_data *hw_data;
>
> @@ -906,6 +913,58 @@ static unsigned long ub953_calc_clkout_ub971(struct ub953_data *priv,
> return res;
> }
>
> +static void ub953_calc_clkout_params(struct ub953_data *priv,
> + unsigned long target_rate,
> + struct ub953_clkout_data *clkout_data)
> +{
> + struct device *dev = &priv->client->dev;
> + unsigned long clkout_rate;
> + u64 fc_rate;
> +
> + fc_rate = ub953_get_fc_rate(priv);
> +
> + if (priv->hw_data->is_ub971) {
> + u8 m, n;
> +
> + clkout_rate = ub953_calc_clkout_ub971(priv, target_rate,
> + fc_rate, &m, &n);
> +
> + clkout_data->m = m;
> + clkout_data->n = n;
> +
> + dev_dbg(dev, "%s %llu * %u / (8 * %u) = %lu (requested %lu)",
> + __func__, fc_rate, m, n, clkout_rate, target_rate);
> + } else {
> + u8 hs_div, m, n;
> +
> + clkout_rate = ub953_calc_clkout_ub953(priv, target_rate,
> + fc_rate, &hs_div, &m, &n);
> +
> + clkout_data->hs_div = hs_div;
> + clkout_data->m = m;
> + clkout_data->n = n;
> +
> + dev_dbg(dev, "%s %llu / %u * %u / %u = %lu (requested %lu)",
> + __func__, fc_rate, hs_div, m, n, clkout_rate,
> + target_rate);
> + }
> +
> + clkout_data->rate = clkout_rate;
> +}
> +
> +static void ub953_write_clkout_regs(struct ub953_data *priv,
> + struct ub953_clkout_data *clkout_data)
const
> +{
> + if (priv->hw_data->is_ub971) {
> + ub953_write(priv, UB953_REG_CLKOUT_CTRL0, clkout_data->m);
> + ub953_write(priv, UB953_REG_CLKOUT_CTRL1, clkout_data->n);
This line is common to both branches, you could move it after the
conditional part.
> + } else {
> + ub953_write(priv, UB953_REG_CLKOUT_CTRL0,
> + (__ffs(clkout_data->hs_div) << 5) | clkout_data->m);
> + ub953_write(priv, UB953_REG_CLKOUT_CTRL1, clkout_data->n);
> + }
> +}
> +
> static unsigned long ub953_clkout_recalc_rate(struct clk_hw *hw,
> unsigned long parent_rate)
> {
> @@ -965,52 +1024,25 @@ static long ub953_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
> unsigned long *parent_rate)
> {
> struct ub953_data *priv = container_of(hw, struct ub953_data, clkout_clk_hw);
> - struct device *dev = &priv->client->dev;
> - unsigned long res;
> - u64 fc_rate;
> - u8 hs_div, m, n;
> -
> - fc_rate = ub953_get_fc_rate(priv);
> + struct ub953_clkout_data clkout_data;
>
> - if (priv->hw_data->is_ub971) {
> - res = ub953_calc_clkout_ub971(priv, rate, fc_rate, &m, &n);
> + ub953_calc_clkout_params(priv, rate, &clkout_data);
>
> - dev_dbg(dev, "%s %llu * %u / (8 * %u) = %lu (requested %lu)",
> - __func__, fc_rate, m, n, res, rate);
> - } else {
> - res = ub953_calc_clkout_ub953(priv, rate, fc_rate, &hs_div, &m, &n);
> -
> - dev_dbg(dev, "%s %llu / %u * %u / %u = %lu (requested %lu)",
> - __func__, fc_rate, hs_div, m, n, res, rate);
> - }
> -
> - return res;
> + return clkout_data.rate;
> }
>
> static int ub953_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
> unsigned long parent_rate)
> {
> struct ub953_data *priv = container_of(hw, struct ub953_data, clkout_clk_hw);
> - u64 fc_rate;
> - u8 hs_div, m, n;
> - unsigned long res;
> + struct ub953_clkout_data clkout_data;
>
> - fc_rate = ub953_get_fc_rate(priv);
> -
> - if (priv->hw_data->is_ub971) {
> - res = ub953_calc_clkout_ub971(priv, rate, fc_rate, &m, &n);
> -
> - ub953_write(priv, UB953_REG_CLKOUT_CTRL0, m);
> - ub953_write(priv, UB953_REG_CLKOUT_CTRL1, n);
> - } else {
> - res = ub953_calc_clkout_ub953(priv, rate, fc_rate, &hs_div, &m, &n);
> + ub953_calc_clkout_params(priv, rate, &clkout_data);
>
> - ub953_write(priv, UB953_REG_CLKOUT_CTRL0, (__ffs(hs_div) << 5) | m);
> - ub953_write(priv, UB953_REG_CLKOUT_CTRL1, n);
> - }
> + dev_dbg(&priv->client->dev, "%s %lu (requested %lu)\n", __func__,
> + clkout_data.rate, rate);
>
> - dev_dbg(&priv->client->dev, "%s %lu (requested %lu)\n", __func__, res,
> - rate);
> + ub953_write_clkout_regs(priv, &clkout_data);
>
> return 0;
> }
> @@ -1021,32 +1053,6 @@ static const struct clk_ops ub953_clkout_ops = {
> .set_rate = ub953_clkout_set_rate,
> };
>
> -static void ub953_init_clkout_ub953(struct ub953_data *priv)
> -{
> - u64 fc_rate;
> - u8 hs_div, m, n;
> -
> - fc_rate = ub953_get_fc_rate(priv);
> -
> - ub953_calc_clkout_ub953(priv, 25000000, fc_rate, &hs_div, &m, &n);
> -
> - ub953_write(priv, UB953_REG_CLKOUT_CTRL0, (__ffs(hs_div) << 5) | m);
> - ub953_write(priv, UB953_REG_CLKOUT_CTRL1, n);
> -}
> -
> -static void ub953_init_clkout_ub971(struct ub953_data *priv)
> -{
> - u64 fc_rate;
> - u8 m, n;
> -
> - fc_rate = ub953_get_fc_rate(priv);
> -
> - ub953_calc_clkout_ub971(priv, 25000000, fc_rate, &m, &n);
> -
> - ub953_write(priv, UB953_REG_CLKOUT_CTRL0, m);
> - ub953_write(priv, UB953_REG_CLKOUT_CTRL1, n);
> -}
> -
> static int ub953_register_clkout(struct ub953_data *priv)
> {
> struct device *dev = &priv->client->dev;
> @@ -1055,16 +1061,15 @@ static int ub953_register_clkout(struct ub953_data *priv)
> priv->hw_data->model, dev_name(dev)),
> .ops = &ub953_clkout_ops,
> };
> + struct ub953_clkout_data clkout_data;
> int ret;
>
> if (!init.name)
> return -ENOMEM;
>
> /* Initialize clkout to 25MHz by default */
> - if (priv->hw_data->is_ub971)
> - ub953_init_clkout_ub971(priv);
> - else
> - ub953_init_clkout_ub953(priv);
> + ub953_calc_clkout_params(priv, 25000000, &clkout_data);
While at it, a macro to replace the numerical constant could be nice.
Reviewed-by: Laurent Pinchart <laurent.pinchart@...asonboard.com>
> + ub953_write_clkout_regs(priv, &clkout_data);
>
> priv->clkout_clk_hw.init = &init;
>
>
--
Regards,
Laurent Pinchart
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