From: viresh.kumar@st.com (Viresh Kumar)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH V3 5/8] SPEAr: clk: Add Fractional Synthesizer clock
Date: Thu, 3 May 2012 11:16:53 +0530 [thread overview]
Message-ID: <4FA21BCD.8070406@st.com> (raw)
In-Reply-To: <0362a8aa32b249be3139b74c688e0a79e0548061.1335249846.git.viresh.kumar@st.com>
On 4/24/2012 12:20 PM, Viresh KUMAR wrote:
> All SPEAr SoC's contain Fractional Synthesizers. Their Fout is derived from
> following equations:
>
> Fout = Fin / (2 * div) (division factor)
> div is 17 bits:-
> 0-13 (fractional part)
> 14-16 (integer part)
> div is (16-14 bits).(13-0 bits) (in binary)
>
> Fout = Fin/(2 * div)
> Fout = ((Fin / 10000)/(2 * div)) * 10000
> Fout = (2^14 * (Fin / 10000)/(2^14 * (2 * div))) * 10000
> Fout = (((Fin / 10000) << 14)/(2 * (div << 14))) * 10000
>
> div << 14 is simply 17 bit value written@register.
>
> This patch adds in support for this type of clock.
>
> Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Another fixup:
---
drivers/clk/spear/clk-frac-synth.c | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)
diff --git a/drivers/clk/spear/clk-frac-synth.c b/drivers/clk/spear/clk-frac-synth.c
index b2090f8..9915dbc 100644
--- a/drivers/clk/spear/clk-frac-synth.c
+++ b/drivers/clk/spear/clk-frac-synth.c
@@ -59,10 +59,9 @@ static long clk_frac_round_rate(struct clk_hw *hw, unsigned long drate,
unsigned long *prate)
{
struct clk_frac *frac = to_clk_frac(hw);
- unsigned long parent_rate = __clk_get_rate(__clk_get_parent(hw->clk));
int unused;
- return clk_round_rate_index(hw, drate, parent_rate, frac_calc_rate,
+ return clk_round_rate_index(hw, drate, *prate, frac_calc_rate,
frac->rtbl_cnt, &unused);
}
--
viresh
next prev parent reply other threads:[~2012-05-03 5:46 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-24 6:50 [PATCH V3 0/8] SPEAr: Move to common clock framework Viresh Kumar
2012-04-24 6:50 ` [PATCH V3 1/8] CLKDEV: Add helper routines to allocate and add clkdevs for given struct clk * Viresh Kumar
2012-04-26 7:47 ` Russell King - ARM Linux
2012-04-26 10:28 ` Viresh Kumar
2012-04-28 9:52 ` Russell King - ARM Linux
2012-04-28 11:01 ` Sascha Hauer
2012-04-28 11:06 ` Russell King - ARM Linux
2012-05-01 8:45 ` Viresh Kumar
2012-05-01 12:31 ` Shawn Guo
2012-05-02 9:54 ` Russell King - ARM Linux
2012-05-02 13:59 ` Shawn Guo
2012-05-02 14:13 ` Russell King - ARM Linux
2012-04-30 8:08 ` Viresh Kumar
2012-04-24 6:50 ` [PATCH V3 2/8] clk: add a fixed factor clock Viresh Kumar
2012-04-27 4:43 ` Viresh Kumar
2012-05-02 9:48 ` Sascha Hauer
2012-05-02 11:56 ` Viresh Kumar
2012-05-02 22:41 ` Mike Turquette
2012-05-02 22:44 ` Mike Turquette
2012-05-02 23:31 ` Russell King - ARM Linux
2012-05-03 5:32 ` Viresh Kumar
2012-05-03 6:37 ` Sascha Hauer
2012-05-03 9:48 ` Viresh Kumar
2012-04-24 6:50 ` [PATCH V3 3/8] SPEAr: clk: Add VCO-PLL Synthesizer clock Viresh Kumar
2012-04-27 4:44 ` Viresh Kumar
2012-05-03 5:47 ` Viresh Kumar
2012-05-03 9:49 ` Viresh Kumar
2012-04-24 6:50 ` [PATCH V3 4/8] SPEAr: clk: Add Auxiliary " Viresh Kumar
2012-04-27 4:45 ` Viresh Kumar
2012-05-03 5:47 ` Viresh Kumar
2012-05-03 9:50 ` Viresh Kumar
2012-04-24 6:50 ` [PATCH V3 5/8] SPEAr: clk: Add Fractional " Viresh Kumar
2012-04-27 4:45 ` Viresh Kumar
2012-05-03 5:46 ` Viresh Kumar [this message]
2012-05-03 9:51 ` Viresh Kumar
2012-04-24 6:50 ` [PATCH V3 6/8] SPEAr: clk: Add General Purpose Timer " Viresh Kumar
2012-04-27 4:46 ` Viresh Kumar
2012-05-03 5:43 ` Viresh Kumar
2012-05-03 9:51 ` Viresh Kumar
2012-04-24 6:50 ` [PATCH V3 7/8] SPEAr: Call clk_prepare() before calling clk_enable Viresh Kumar
2012-04-27 4:42 ` [PATCH V3 0/8] SPEAr: Move to common clock framework Viresh Kumar
2012-04-27 17:50 ` Turquette, Mike
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