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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

  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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