Hi Stephen, Am Dienstag, 22. September 2015, 16:19:00 schrieb Stephen Boyd: > On 09/23, Heiko Stübner wrote: > > Am Dienstag, 22. September 2015, 15:41:25 schrieb Stephen Boyd: > > > On 09/17, Xing Zheng wrote: > > > > + > > > > +static void rockchip_rk3036_pll_init(struct clk_hw *hw) > > > > > > init ops are "discouraged". Could we do this through assigned > > > rates instead? > > > > really? According to Mike that was a valid use-case when we looked for an > > initial place for that on the rk3288 :-) . > > A comment in clk.c indicates init ops are discouraged. Maybe this > is a valid use-case on other platforms so it was allowed, but > pretty much every time we see a new init op we have to think > about it and justify it. Hooray!
for the rk3288-variant Mike said "Looks good to me. I think rk3xxx might be the first user of the .init callback!" [0] so it looks like he was convinced of our reasoning at the time :-) . [0] http://lists.infradead.org/pipermail/linux-rockchip/2014-November/001570.html > > > > +{ > > > > + struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw); > > > > + const struct rockchip_pll_rate_table *rate; > > > > + unsigned int fbdiv, postdiv1, refdiv, postdiv2, dsmpd, frac; > > > > + unsigned long drate; > > > > + u32 pllcon; > > > > + > > > > + if (!(pll->flags & ROCKCHIP_PLL_SYNC_RATE)) > > > > + return; > > > > > > I don't understand what this one does though. This check isn't in > > > the set rate ops. > > > > And it shouldn't be :-) > > > > The issue this whole thing is trying to solve is aligning the pll settings > > which what we have in the rate table, not what the bootloader set. > > > > For example the bootloader could set up a pll at 594MHz with one set of > > parameters and after some time - when you don't want to exchange > > bootloaders on shipping devices anymore - it comes to light that a > > different set of parameters for the same frequency produces for example a > > more stable hdmi signal [I think that was the main reason for the initial > > change]. > > > > So we're not changing the frequency x -> y, which could be easily done > > [and is done already] via assigned-rates, but instead > > > > x {params a,b,c} -> x {params d,e,f} > > > > so the rate itself stays the same, only the frequency generation is > > adapted. > Ok. It would be nice if this sort of information was made into a > comment and put in the code. Or at least the commit text for the > change. > > And is there any reason that we need to get the parent clock and > parent rate to align the PLL settings? > It would be nice if we > avoided using clk_* APIs in here, by extracting the pll set rate > code into another function that we can call from init to make the > values the same without all the fallback to old rates, etc. I guess you want Xing Zheng to change his pll code somewhat like the following, right? While starting off as proof-of-concept, that change below actually does work quite nicely on rk3288 boards. ---------------- 8< -------------------- From: Heiko Stuebner <[email protected]> Subject: [PATCH] clk: rockchip: don't use clk_ APIs in the pll init-callback Separate the update of pll registers from the actual set_rate function so that the init callback does not need to access clk-API functions. As we now have separated the getting and setting of the pll parameters we can also directly use these new functions in other places too. Signed-off-by: Heiko Stuebner <[email protected]> --- drivers/clk/rockchip/clk-pll.c | 135 ++++++++++++++++++++++------------------- 1 file changed, 74 insertions(+), 61 deletions(-) diff --git a/drivers/clk/rockchip/clk-pll.c b/drivers/clk/rockchip/clk-pll.c index 7737a1d..4881eb8 100644 --- a/drivers/clk/rockchip/clk-pll.c +++ b/drivers/clk/rockchip/clk-pll.c @@ -126,11 +126,32 @@ static int rockchip_pll_wait_lock(struct rockchip_clk_pll *pll) #define RK3066_PLLCON3_PWRDOWN (1 << 1) #define RK3066_PLLCON3_BYPASS (1 << 0) +static void rockchip_rk3066_pll_get_params(struct rockchip_clk_pll *pll, + struct rockchip_pll_rate_table *rate) +{ + u32 pllcon; + + pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(0)); + rate->nr = ((pllcon >> RK3066_PLLCON0_NR_SHIFT) + & RK3066_PLLCON0_NR_MASK) + 1; + rate->no = ((pllcon >> RK3066_PLLCON0_OD_SHIFT) + & RK3066_PLLCON0_OD_MASK) + 1; + + pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(1)); + rate->nf = ((pllcon >> RK3066_PLLCON1_NF_SHIFT) + & RK3066_PLLCON1_NF_MASK) + 1; + + pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(2)); + rate->nb = ((pllcon >> RK3066_PLLCON2_NB_SHIFT) + & RK3066_PLLCON2_NB_MASK) + 1; +} + static unsigned long rockchip_rk3066_pll_recalc_rate(struct clk_hw *hw, unsigned long prate) { struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw); - u64 nf, nr, no, rate64 = prate; + struct rockchip_pll_rate_table cur; + u64 rate64 = prate; u32 pllcon; pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(3)); @@ -140,53 +161,31 @@ static unsigned long rockchip_rk3066_pll_recalc_rate(struct clk_hw *hw, return prate; } - pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(1)); - nf = (pllcon >> RK3066_PLLCON1_NF_SHIFT) & RK3066_PLLCON1_NF_MASK; - - pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(0)); - nr = (pllcon >> RK3066_PLLCON0_NR_SHIFT) & RK3066_PLLCON0_NR_MASK; - no = (pllcon >> RK3066_PLLCON0_OD_SHIFT) & RK3066_PLLCON0_OD_MASK; + rockchip_rk3066_pll_get_params(pll, &cur); - rate64 *= (nf + 1); - do_div(rate64, nr + 1); - do_div(rate64, no + 1); + rate64 *= cur.nf; + do_div(rate64, cur.nr); + do_div(rate64, cur.no); return (unsigned long)rate64; } -static int rockchip_rk3066_pll_set_rate(struct clk_hw *hw, unsigned long drate, - unsigned long prate) +static int rockchip_rk3066_pll_set_params(struct rockchip_clk_pll *pll, + const struct rockchip_pll_rate_table *rate) { - struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw); - const struct rockchip_pll_rate_table *rate; - unsigned long old_rate = rockchip_rk3066_pll_recalc_rate(hw, prate); - struct regmap *grf = rockchip_clk_get_grf(); - struct clk_mux *pll_mux = &pll->pll_mux; const struct clk_ops *pll_mux_ops = pll->pll_mux_ops; + struct clk_mux *pll_mux = &pll->pll_mux; + struct rockchip_pll_rate_table cur; int rate_change_remuxed = 0; int cur_parent; int ret; - if (IS_ERR(grf)) { - pr_debug("%s: grf regmap not available, aborting rate change\n", - __func__); - return PTR_ERR(grf); - } - - pr_debug("%s: changing %s from %lu to %lu with a parent rate of %lu\n", - __func__, clk_hw_get_name(hw), old_rate, drate, prate); - - /* Get required rate settings from table */ - rate = rockchip_get_pll_settings(pll, drate); - if (!rate) { - pr_err("%s: Invalid rate : %lu for pll clk %s\n", __func__, - drate, clk_hw_get_name(hw)); - return -EINVAL; - } - pr_debug("%s: rate settings for %lu (nr, no, nf): (%d, %d, %d)\n", __func__, rate->rate, rate->nr, rate->no, rate->nf); + rockchip_rk3066_pll_get_params(pll, &cur); + cur.rate = 0; + cur_parent = pll_mux_ops->get_parent(&pll_mux->hw); if (cur_parent == PLL_MODE_NORM) { pll_mux_ops->set_parent(&pll_mux->hw, PLL_MODE_SLOW); @@ -219,9 +218,9 @@ static int rockchip_rk3066_pll_set_rate(struct clk_hw *hw, unsigned long drate, /* wait for the pll to lock */ ret = rockchip_pll_wait_lock(pll); if (ret) { - pr_warn("%s: pll did not lock, trying to restore old rate %lu\n", - __func__, old_rate); - rockchip_rk3066_pll_set_rate(hw, old_rate, prate); + pr_warn("%s: pll update unsucessful, trying to restore old params\n", + __func__); + rockchip_rk3066_pll_set_params(pll, &cur); } if (rate_change_remuxed) @@ -230,6 +229,34 @@ static int rockchip_rk3066_pll_set_rate(struct clk_hw *hw, unsigned long drate, return ret; } +static int rockchip_rk3066_pll_set_rate(struct clk_hw *hw, unsigned long drate, + unsigned long prate) +{ + struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw); + const struct rockchip_pll_rate_table *rate; + unsigned long old_rate = rockchip_rk3066_pll_recalc_rate(hw, prate); + struct regmap *grf = rockchip_clk_get_grf(); + + if (IS_ERR(grf)) { + pr_debug("%s: grf regmap not available, aborting rate change\n", + __func__); + return PTR_ERR(grf); + } + + pr_debug("%s: changing %s from %lu to %lu with a parent rate of %lu\n", + __func__, clk_hw_get_name(hw), old_rate, drate, prate); + + /* Get required rate settings from table */ + rate = rockchip_get_pll_settings(pll, drate); + if (!rate) { + pr_err("%s: Invalid rate : %lu for pll clk %s\n", __func__, + drate, clk_hw_get_name(hw)); + return -EINVAL; + } + + return rockchip_rk3066_pll_set_params(pll, rate); +} + static int rockchip_rk3066_pll_enable(struct clk_hw *hw) { struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw); @@ -261,9 +288,8 @@ 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, nb; + struct rockchip_pll_rate_table cur; unsigned long drate; - u32 pllcon; if (!(pll->flags & ROCKCHIP_PLL_SYNC_RATE)) return; @@ -275,34 +301,21 @@ static void rockchip_rk3066_pll_init(struct clk_hw *hw) if (!rate) return; - pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(0)); - nr = ((pllcon >> RK3066_PLLCON0_NR_SHIFT) & RK3066_PLLCON0_NR_MASK) + 1; - no = ((pllcon >> RK3066_PLLCON0_OD_SHIFT) & RK3066_PLLCON0_OD_MASK) + 1; - - pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(1)); - nf = ((pllcon >> RK3066_PLLCON1_NF_SHIFT) & RK3066_PLLCON1_NF_MASK) + 1; - - pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(2)); - nb = ((pllcon >> RK3066_PLLCON2_NB_SHIFT) & RK3066_PLLCON2_NB_MASK) + 1; + rockchip_rk3066_pll_get_params(pll, &cur); pr_debug("%s: pll %s@%lu: nr (%d:%d); no (%d:%d); nf(%d:%d), nb(%d:%d)\n", - __func__, clk_hw_get_name(hw), drate, rate->nr, nr, - rate->no, no, rate->nf, nf, rate->nb, nb); - if (rate->nr != nr || rate->no != no || rate->nf != nf - || rate->nb != nb) { - struct clk_hw *parent = clk_hw_get_parent(hw); - unsigned long prate; - - if (!parent) { - pr_warn("%s: parent of %s not available\n", - __func__, clk_hw_get_name(hw)); + __func__, clk_hw_get_name(hw), drate, rate->nr, cur.nr, + rate->no, cur.no, rate->nf, cur.nf, rate->nb, cur.nb); + if (rate->nr != cur.nr || rate->no != cur.no || rate->nf != cur.nf + || rate->nb != cur.nb) { + struct regmap *grf = rockchip_clk_get_grf(); + + if (IS_ERR(grf)) return; - } pr_debug("%s: pll %s: rate params do not match rate table, adjusting\n", __func__, clk_hw_get_name(hw)); - prate = clk_hw_get_rate(parent); - rockchip_rk3066_pll_set_rate(hw, drate, prate); + rockchip_rk3066_pll_set_params(pll, rate); } } -- 2.5.3 ---------------- 8< -------------------- Heiko -- To unsubscribe from this list: send the line "unsubscribe linux-clk" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
