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| author |   Douglas Anderson <dianders@chromium.org> | 2015-07-21 13:41:23 -0700 |
|---|---|---|
| committer |   Stephen Boyd <sboyd@codeaurora.org> | 2015-07-28 11:59:12 -0700 |
| commit | 2bbfe00147a7c075f5c43e657ec218afea662819 (patch) | |
| tree | 25400d1f396ff92dc53a9153db5af4ebd31cffff /drivers/clk/rockchip/clk-pll.c | |
| parent | Merge branch 'cleanup-clk-h-includes' into clk-next (diff) | |
| download | linux-dev-2bbfe00147a7c075f5c43e657ec218afea662819.tar.xz linux-dev-2bbfe00147a7c075f5c43e657ec218afea662819.zip | |
clk: rockchip: Fix PLL bandwidth
In the TRM we see that BWADJ is "a 12-bit bus that selects the values
1-4096 for the bandwidth divider (NB)":
NB = BWADJ[11:0] + 1
The recommended setting of NB: NB = NF / 2.
So:
NB = NF / 2
BWADJ[11:0] + 1 = NF / 2
BWADJ[11:0] = NF / 2 - 1
Right now, we have:
{ \
.rate = _rate##U, \
.nr = _nr, \
.nf = _nf, \
.no = _no, \
.bwadj = (_nf >> 1), \
}
That means we set bwadj to NF / 2, not NF / 2 - 1
All of this is a bit confusing because we specify "NR" (the 1-based
value), "NF" (the 1-based value), "NO" (the 1-based value), but
"BWADJ" (the 0-based value) instead of "NB" (the 1-based value).
Let's change to working with "NB" and fix the off by one error. This
may affect PLL jitter in a small way (hopefully for the better).
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Diffstat (limited to 'drivers/clk/rockchip/clk-pll.c')
| -rw-r--r-- | drivers/clk/rockchip/clk-pll.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/drivers/clk/rockchip/clk-pll.c b/drivers/clk/rockchip/clk-pll.c index 1f88dd158b93..96903ae8b192 100644 --- a/drivers/clk/rockchip/clk-pll.c +++ b/drivers/clk/rockchip/clk-pll.c @@ -120,8 +120,8 @@ static int rockchip_pll_wait_lock(struct rockchip_clk_pll *pll) #define RK3066_PLLCON0_NR_SHIFT 8 #define RK3066_PLLCON1_NF_MASK 0x1fff #define RK3066_PLLCON1_NF_SHIFT 0 -#define RK3066_PLLCON2_BWADJ_MASK 0xfff -#define RK3066_PLLCON2_BWADJ_SHIFT 0 +#define RK3066_PLLCON2_NB_MASK 0xfff +#define RK3066_PLLCON2_NB_SHIFT 0 #define RK3066_PLLCON3_RESET (1 << 5) #define RK3066_PLLCON3_PWRDOWN (1 << 1) #define RK3066_PLLCON3_BYPASS (1 << 0) @@ -207,8 +207,8 @@ static int rockchip_rk3066_pll_set_rate(struct clk_hw *hw, unsigned long drate, writel_relaxed(HIWORD_UPDATE(rate->nf - 1, RK3066_PLLCON1_NF_MASK, RK3066_PLLCON1_NF_SHIFT), pll->reg_base + RK3066_PLLCON(1)); - writel_relaxed(HIWORD_UPDATE(rate->bwadj, RK3066_PLLCON2_BWADJ_MASK, - RK3066_PLLCON2_BWADJ_SHIFT), + writel_relaxed(HIWORD_UPDATE(rate->nb - 1, RK3066_PLLCON2_NB_MASK, + RK3066_PLLCON2_NB_SHIFT), pll->reg_base + RK3066_PLLCON(2)); /* leave reset and wait the reset_delay */ @@ -261,7 +261,7 @@ static void rockchip_rk3066_pll_init(struct clk_hw *hw) { struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw); const struct rockchip_pll_rate_table *rate; - unsigned int nf, nr, no, bwadj; + unsigned int nf, nr, no, nb; unsigned long drate; u32 pllcon; @@ -283,13 +283,13 @@ static void rockchip_rk3066_pll_init(struct clk_hw *hw) nf = ((pllcon >> RK3066_PLLCON1_NF_SHIFT) & RK3066_PLLCON1_NF_MASK) + 1; pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(2)); - bwadj = (pllcon >> RK3066_PLLCON2_BWADJ_SHIFT) & RK3066_PLLCON2_BWADJ_MASK; + nb = ((pllcon >> RK3066_PLLCON2_NB_SHIFT) & RK3066_PLLCON2_NB_MASK) + 1; - pr_debug("%s: pll %s@%lu: nr (%d:%d); no (%d:%d); nf(%d:%d), bwadj(%d:%d)\n", + pr_debug("%s: pll %s@%lu: nr (%d:%d); no (%d:%d); nf(%d:%d), nb(%d:%d)\n", __func__, __clk_get_name(hw->clk), drate, rate->nr, nr, - rate->no, no, rate->nf, nf, rate->bwadj, bwadj); + rate->no, no, rate->nf, nf, rate->nb, nb); if (rate->nr != nr || rate->no != no || rate->nf != nf - || rate->bwadj != bwadj) { + || rate->nb != nb) { struct clk *parent = __clk_get_parent(hw->clk); unsigned long prate; |