diff options
Diffstat (limited to 'drivers/clk/qcom/clk-rcg2.c')
| -rw-r--r-- | drivers/clk/qcom/clk-rcg2.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c index 5183c74b07..30b19bd39d 100644 --- a/drivers/clk/qcom/clk-rcg2.c +++ b/drivers/clk/qcom/clk-rcg2.c @@ -260,6 +260,115 @@ static int _freq_tbl_determine_rate(struct clk_hw *hw, const struct freq_tbl *f, return 0; } +static const struct freq_conf * +__clk_rcg2_select_conf(struct clk_hw *hw, const struct freq_multi_tbl *f, + unsigned long req_rate) +{ + unsigned long rate_diff, best_rate_diff = ULONG_MAX; + const struct freq_conf *conf, *best_conf = NULL; + struct clk_rcg2 *rcg = to_clk_rcg2(hw); + const char *name = clk_hw_get_name(hw); + unsigned long parent_rate, rate; + struct clk_hw *p; + int index, i; + + /* Exit early if only one config is defined */ + if (f->num_confs == 1) { + best_conf = f->confs; + goto exit; + } + + /* Search in each provided config the one that is near the wanted rate */ + for (i = 0, conf = f->confs; i < f->num_confs; i++, conf++) { + index = qcom_find_src_index(hw, rcg->parent_map, conf->src); + if (index < 0) + continue; + + p = clk_hw_get_parent_by_index(hw, index); + if (!p) + continue; + + parent_rate = clk_hw_get_rate(p); + rate = calc_rate(parent_rate, conf->n, conf->m, conf->n, conf->pre_div); + + if (rate == req_rate) { + best_conf = conf; + goto exit; + } + + rate_diff = abs_diff(req_rate, rate); + if (rate_diff < best_rate_diff) { + best_rate_diff = rate_diff; + best_conf = conf; + } + } + + /* + * Very unlikely. Warn if we couldn't find a correct config + * due to parent not found in every config. + */ + if (unlikely(!best_conf)) { + WARN(1, "%s: can't find a configuration for rate %lu\n", + name, req_rate); + return ERR_PTR(-EINVAL); + } + +exit: + return best_conf; +} + +static int _freq_tbl_fm_determine_rate(struct clk_hw *hw, const struct freq_multi_tbl *f, + struct clk_rate_request *req) +{ + unsigned long clk_flags, rate = req->rate; + struct clk_rcg2 *rcg = to_clk_rcg2(hw); + const struct freq_conf *conf; + struct clk_hw *p; + int index; + + f = qcom_find_freq_multi(f, rate); + if (!f || !f->confs) + return -EINVAL; + + conf = __clk_rcg2_select_conf(hw, f, rate); + if (IS_ERR(conf)) + return PTR_ERR(conf); + index = qcom_find_src_index(hw, rcg->parent_map, conf->src); + if (index < 0) + return index; + + clk_flags = clk_hw_get_flags(hw); + p = clk_hw_get_parent_by_index(hw, index); + if (!p) + return -EINVAL; + + if (clk_flags & CLK_SET_RATE_PARENT) { + rate = f->freq; + if (conf->pre_div) { + if (!rate) + rate = req->rate; + rate /= 2; + rate *= conf->pre_div + 1; + } + + if (conf->n) { + u64 tmp = rate; + + tmp = tmp * conf->n; + do_div(tmp, conf->m); + rate = tmp; + } + } else { + rate = clk_hw_get_rate(p); + } + + req->best_parent_hw = p; + req->best_parent_rate = rate; + req->rate = f->freq; + + return 0; +} + static int clk_rcg2_determine_rate(struct clk_hw *hw, struct clk_rate_request *req) { @@ -276,6 +385,14 @@ static int clk_rcg2_determine_floor_rate(struct clk_hw *hw, return _freq_tbl_determine_rate(hw, rcg->freq_tbl, req, FLOOR); } +static int clk_rcg2_fm_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + struct clk_rcg2 *rcg = to_clk_rcg2(hw); + + return _freq_tbl_fm_determine_rate(hw, rcg->freq_multi_tbl, req); +} + static int __clk_rcg2_configure(struct clk_rcg2 *rcg, const struct freq_tbl *f, u32 *_cfg) { @@ -371,6 +488,30 @@ static int __clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate, return clk_rcg2_configure(rcg, f); } +static int __clk_rcg2_fm_set_rate(struct clk_hw *hw, unsigned long rate) +{ + struct clk_rcg2 *rcg = to_clk_rcg2(hw); + const struct freq_multi_tbl *f; + const struct freq_conf *conf; + struct freq_tbl f_tbl = {}; + + f = qcom_find_freq_multi(rcg->freq_multi_tbl, rate); + if (!f || !f->confs) + return -EINVAL; + + conf = __clk_rcg2_select_conf(hw, f, rate); + if (IS_ERR(conf)) + return PTR_ERR(conf); + + f_tbl.freq = f->freq; + f_tbl.src = conf->src; + f_tbl.pre_div = conf->pre_div; + f_tbl.m = conf->m; + f_tbl.n = conf->n; + + return clk_rcg2_configure(rcg, &f_tbl); +} + static int clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate) { @@ -383,6 +524,12 @@ static int clk_rcg2_set_floor_rate(struct clk_hw *hw, unsigned long rate, return __clk_rcg2_set_rate(hw, rate, FLOOR); } +static int clk_rcg2_fm_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + return __clk_rcg2_fm_set_rate(hw, rate); +} + static int clk_rcg2_set_rate_and_parent(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate, u8 index) { @@ -395,6 +542,12 @@ static int clk_rcg2_set_floor_rate_and_parent(struct clk_hw *hw, return __clk_rcg2_set_rate(hw, rate, FLOOR); } +static int clk_rcg2_fm_set_rate_and_parent(struct clk_hw *hw, + unsigned long rate, unsigned long parent_rate, u8 index) +{ + return __clk_rcg2_fm_set_rate(hw, rate); +} + static int clk_rcg2_get_duty_cycle(struct clk_hw *hw, struct clk_duty *duty) { struct clk_rcg2 *rcg = to_clk_rcg2(hw); @@ -505,6 +658,19 @@ const struct clk_ops clk_rcg2_floor_ops = { }; EXPORT_SYMBOL_GPL(clk_rcg2_floor_ops); +const struct clk_ops clk_rcg2_fm_ops = { + .is_enabled = clk_rcg2_is_enabled, + .get_parent = clk_rcg2_get_parent, + .set_parent = clk_rcg2_set_parent, + .recalc_rate = clk_rcg2_recalc_rate, + .determine_rate = clk_rcg2_fm_determine_rate, + .set_rate = clk_rcg2_fm_set_rate, + .set_rate_and_parent = clk_rcg2_fm_set_rate_and_parent, + .get_duty_cycle = clk_rcg2_get_duty_cycle, + .set_duty_cycle = clk_rcg2_set_duty_cycle, +}; +EXPORT_SYMBOL_GPL(clk_rcg2_fm_ops); + const struct clk_ops clk_rcg2_mux_closest_ops = { .determine_rate = __clk_mux_determine_rate_closest, .get_parent = clk_rcg2_get_parent, @@ -1138,7 +1304,39 @@ clk_rcg2_shared_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) return clk_rcg2_recalc_rate(hw, parent_rate); } +static int clk_rcg2_shared_init(struct clk_hw *hw) +{ + /* + * This does a few things: + * + * 1. Sets rcg->parked_cfg to reflect the value at probe so that the + * proper parent is reported from clk_rcg2_shared_get_parent(). + * + * 2. Clears the force enable bit of the RCG because we rely on child + * clks (branches) to turn the RCG on/off with a hardware feedback + * mechanism and only set the force enable bit in the RCG when we + * want to make sure the clk stays on for parent switches or + * parking. + * + * 3. Parks shared RCGs on the safe source at registration because we + * can't be certain that the parent clk will stay on during boot, + * especially if the parent is shared. If this RCG is enabled at + * boot, and the parent is turned off, the RCG will get stuck on. A + * GDSC can wedge if is turned on and the RCG is stuck on because + * the GDSC's controller will hang waiting for the clk status to + * toggle on when it never does. + * + * The safest option here is to "park" the RCG at init so that the clk + * can never get stuck on or off. This ensures the GDSC can't get + * wedged. + */ + clk_rcg2_shared_disable(hw); + + return 0; +} + const struct clk_ops clk_rcg2_shared_ops = { + .init = clk_rcg2_shared_init, .enable = clk_rcg2_shared_enable, .disable = clk_rcg2_shared_disable, .get_parent = clk_rcg2_shared_get_parent, |