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From: Archit Taneja <archit@ti.com>
To: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: linux-omap@vger.kernel.org, linux-fbdev@vger.kernel.org
Subject: Re: [PATCH 08/14] OMAPDSS: DSS: add new clock calculation code
Date: Wed, 20 Mar 2013 15:29:35 +0000	[thread overview]
Message-ID: <5149D30F.2010801@ti.com> (raw)
In-Reply-To: <1362743569-10289-9-git-send-email-tomi.valkeinen@ti.com>

On Friday 08 March 2013 05:22 PM, Tomi Valkeinen wrote:
> Add new way to iterate over DSS clock divisors. dss_div_calc() provides
> a generic way to go over all the divisors, within given clock range.
> dss_div_calc() will call a callback function for each divider set,
> making the function reusable for all use cases.
>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> ---
>   drivers/video/omap2/dss/dss.c |   36 ++++++++++++++++++++++++++++++++++++
>   drivers/video/omap2/dss/dss.h |    3 +++
>   2 files changed, 39 insertions(+)
>
> diff --git a/drivers/video/omap2/dss/dss.c b/drivers/video/omap2/dss/dss.c
> index 054c2a2..21a3dc8 100644
> --- a/drivers/video/omap2/dss/dss.c
> +++ b/drivers/video/omap2/dss/dss.c
> @@ -473,6 +473,42 @@ int dss_calc_clock_rates(struct dss_clock_info *cinfo)
>   	return 0;
>   }
>
> +bool dss_div_calc(unsigned long fck_min, dss_div_calc_func func, void *data)
> +{
> +	int fckd, fckd_start, fckd_stop;
> +	unsigned long fck;
> +	unsigned long fck_hw_max;
> +	unsigned long fckd_hw_max;
> +	unsigned long prate;
> +
> +	if (dss.dpll4_m4_ck = NULL) {
> +		/* XXX can we change the clock on omap2? */

We can change dss_fclk1 on omap2, and the cclock2420_data.c and 
cclock2430_data.c have clksel structs which allow a set of dividers. The 
dividers are not continuous though, 1 to 12 and 16 are allowed. So we 
might need to change the code here a bit, if we want to change the clock 
in the first place.

Archit

> +		fck = clk_get_rate(dss.dss_clk);
> +		fckd = 1;
> +
> +		return func(fckd, fck, data);
> +	}
> +
> +	fck_hw_max = dss_feat_get_param_max(FEAT_PARAM_DSS_FCK);
> +	fckd_hw_max = dss.feat->fck_div_max;
> +
> +	prate = dss_get_dpll4_rate() * dss.feat->dss_fck_multiplier;
> +
> +	fck_min = fck_min ? fck_min : 1;
> +
> +	fckd_start = min(prate / fck_min, fckd_hw_max);
> +	fckd_stop = max(DIV_ROUND_UP(prate, fck_hw_max), 1ul);
> +
> +	for (fckd = fckd_start; fckd >= fckd_stop; --fckd) {
> +		fck = prate / fckd;
> +
> +		if (func(fckd, fck, data))
> +			return true;
> +	}
> +
> +	return false;
> +}
> +
>   int dss_set_clock_div(struct dss_clock_info *cinfo)
>   {
>   	if (dss.dpll4_m4_ck) {
> diff --git a/drivers/video/omap2/dss/dss.h b/drivers/video/omap2/dss/dss.h
> index 0ff41dd..4180302 100644
> --- a/drivers/video/omap2/dss/dss.h
> +++ b/drivers/video/omap2/dss/dss.h
> @@ -271,6 +271,9 @@ int dss_set_clock_div(struct dss_clock_info *cinfo);
>   int dss_calc_clock_div(unsigned long req_pck, struct dss_clock_info *dss_cinfo,
>   		struct dispc_clock_info *dispc_cinfo);
>
> +typedef bool (*dss_div_calc_func)(int fckd, unsigned long fck, void *data);
> +bool dss_div_calc(unsigned long fck_min, dss_div_calc_func func, void *data);
> +
>   /* SDI */
>   int sdi_init_platform_driver(void) __init;
>   void sdi_uninit_platform_driver(void) __exit;
>


  reply	other threads:[~2013-03-20 15:29 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-08 11:52 [PATCH 00/14] OMAPDSS: new clock calculation + DSI VM Tomi Valkeinen
2013-03-08 11:52 ` [PATCH 01/14] OMAPDSS: DISPC: store core clk rate Tomi Valkeinen
2013-03-20 11:20   ` Archit Taneja
2013-03-20 11:36     ` Tomi Valkeinen
2013-03-08 11:52 ` [PATCH 02/14] OMAPDSS: DSI: fix wrong unsigned long long use Tomi Valkeinen
2013-03-08 11:52 ` [PATCH 03/14] OMAPDSS: DSI: simplify dsi configuration Tomi Valkeinen
2013-03-20 11:36   ` Archit Taneja
2013-03-20 11:44     ` Tomi Valkeinen
2013-03-08 11:52 ` [PATCH 04/14] OMAPDSS: DSI: get line buffer size at probe Tomi Valkeinen
2013-03-08 11:52 ` [PATCH 05/14] OMAPDSS: DSI: add enum omap_dss_dsi_trans_mode Tomi Valkeinen
2013-03-20 11:42   ` Archit Taneja
2013-03-08 11:52 ` [PATCH 06/14] OMAPDSS: DSI remove unneeded clk source setup code Tomi Valkeinen
2013-03-08 11:52 ` [PATCH 07/14] OMAPDSS: DISPC: add new clock calculation code Tomi Valkeinen
2013-03-08 11:52 ` [PATCH 08/14] OMAPDSS: DSS: " Tomi Valkeinen
2013-03-20 15:29   ` Archit Taneja [this message]
2013-03-20 15:28     ` Tomi Valkeinen
2013-03-21  6:26       ` Archit Taneja
2013-03-21  8:13         ` Tomi Valkeinen
2013-03-08 11:52 ` [PATCH 09/14] OMAPDSS: DSI: " Tomi Valkeinen
2013-03-08 11:52 ` [PATCH 10/14] OMAPDSS: SDI: use " Tomi Valkeinen
2013-03-08 11:52 ` [PATCH 11/14] OMAPDSS: DPI: " Tomi Valkeinen
2013-03-08 11:52 ` [PATCH 12/14] OMAPDSS: DSI: " Tomi Valkeinen
2013-03-08 11:52 ` [PATCH 13/14] OMAPDSS: remove unused old " Tomi Valkeinen
2013-03-08 11:52 ` [PATCH 14/14] OMAPDSS: remove dsi videomode from dssdev Tomi Valkeinen

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