Thread (42 messages) 42 messages, 5 authors, 2012-05-03
STALE5172d
Revisions (5)
  1. v1 [diff vs current]
  2. v3 [diff vs current]
  3. v3 current
  4. v3 [diff vs current]
  5. v3 [diff vs current]

[PATCH V3 3/8] SPEAr: clk: Add VCO-PLL Synthesizer clock

From: Viresh Kumar <hidden>
Date: 2012-04-27 04:44:46
Subsystem: common clk framework, spear platform/clock/pinctrl support, the rest · Maintainers: Michael Turquette, Stephen Boyd, Viresh Kumar, Linus Torvalds

On 4/24/2012 12:20 PM, Viresh KUMAR wrote:
All SPEAr SoC's contain PLLs. Their Fout is derived based on following equations

- In normal mode
  vco = (2 * M[15:8] * Fin)/N

- In Dithered mode
  vco = (2 * M[15:0] * Fin)/(256 * N)

pll_rate = vco/2^p

vco and pll are very closely bound to each other,
"vco needs to program: mode, m & n" and "pll needs to program p",
both share common enable/disable logic and registers.

This patch adds in support for this type of clock.
    fixup! SPEAr: clk: Add VCO-PLL Synthesizer clock
---
 drivers/clk/spear/clk-vco-pll.c |   14 +++++++++-----
 drivers/clk/spear/clk.c         |    4 ++--
 drivers/clk/spear/clk.h         |    3 ++-
 3 files changed, 13 insertions(+), 8 deletions(-)
diff --git a/drivers/clk/spear/clk-vco-pll.c b/drivers/clk/spear/clk-vco-pll.c
index 9efa30d..e661273 100644
--- a/drivers/clk/spear/clk-vco-pll.c
+++ b/drivers/clk/spear/clk-vco-pll.c
@@ -141,7 +141,8 @@ static unsigned long clk_pll_recalc_rate(struct clk_hw *hw, unsigned long
        return parent_rate / (1 << p);
 }
 
-static int clk_pll_set_rate(struct clk_hw *hw, unsigned long drate)
+static int clk_pll_set_rate(struct clk_hw *hw, unsigned long drate,
+                               unsigned long prate)
 {
        struct clk_pll *pll = to_clk_pll(hw);
        struct pll_rate_tbl *rtbl = pll->vco->rtbl;
@@ -182,10 +183,11 @@ static long clk_vco_round_rate(struct clk_hw *hw, unsigned long drate,
                unsigned long *prate)
 {
        struct clk_vco *vco = to_clk_vco(hw);
+       unsigned long parent_rate = __clk_get_rate(__clk_get_parent(hw->clk));
        int unused;
 
-       return clk_round_rate_index(hw, drate, vco_calc_rate, vco->rtbl_cnt,
-                       &unused);
+       return clk_round_rate_index(hw, drate, parent_rate, vco_calc_rate,
+                       vco->rtbl_cnt, &unused);
 }
 
 static unsigned long clk_vco_recalc_rate(struct clk_hw *hw,
@@ -226,14 +228,16 @@ static unsigned long clk_vco_recalc_rate(struct clk_hw *hw,
 }
 
 /* Configures new clock rate of vco */
-static int clk_vco_set_rate(struct clk_hw *hw, unsigned long drate)
+static int clk_vco_set_rate(struct clk_hw *hw, unsigned long drate,
+                               unsigned long prate)
 {
        struct clk_vco *vco = to_clk_vco(hw);
        struct pll_rate_tbl *rtbl = vco->rtbl;
        unsigned long flags = 0, val;
        int i;
 
-       clk_round_rate_index(hw, drate, vco_calc_rate, vco->rtbl_cnt, &i);
+       clk_round_rate_index(hw, drate, prate, vco_calc_rate, vco->rtbl_cnt,
+                       &i);
 
        if (vco->lock)
                spin_lock_irqsave(vco->lock, flags);
diff --git a/drivers/clk/spear/clk.c b/drivers/clk/spear/clk.c
index 74f6acc..376d4e5 100644
--- a/drivers/clk/spear/clk.c
+++ b/drivers/clk/spear/clk.c
@@ -14,10 +14,10 @@
 #include "clk.h"
 
 long clk_round_rate_index(struct clk_hw *hw, unsigned long drate,
-               clk_calc_rate calc_rate, u8 rtbl_cnt, int *index)
+               unsigned long parent_rate, clk_calc_rate calc_rate, u8 rtbl_cnt,
+               int *index)
 {
        unsigned long prev_rate, rate = 0;
-       unsigned long parent_rate = __clk_get_rate(__clk_get_parent(hw->clk));
 
        for (*index = 0; *index < rtbl_cnt; (*index)++) {
                prev_rate = rate;
diff --git a/drivers/clk/spear/clk.h b/drivers/clk/spear/clk.h
index ee17994..3321c46 100644
--- a/drivers/clk/spear/clk.h
+++ b/drivers/clk/spear/clk.h
@@ -128,6 +128,7 @@ struct clk *clk_register_vco_pll(const char *vco_name, const char *pll_name,
                struct clk **vco_gate_clk);
 
 long clk_round_rate_index(struct clk_hw *hw, unsigned long drate,
-               clk_calc_rate calc_rate, u8 rtbl_cnt, int *index);
+               unsigned long parent_rate, clk_calc_rate calc_rate, u8 rtbl_cnt,
+               int *index);
 
 #endif /* __SPEAR_CLK_H */

-- 
viresh
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