diff options
Diffstat (limited to 'drivers/clk/bcm/clk-bcm2835.c')
| -rw-r--r-- | drivers/clk/bcm/clk-bcm2835.c | 155 |
1 files changed, 101 insertions, 54 deletions
diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c index 39bf5820297e..015e687ffabe 100644 --- a/drivers/clk/bcm/clk-bcm2835.c +++ b/drivers/clk/bcm/clk-bcm2835.c @@ -807,6 +807,16 @@ static const struct bcm2835_clock_data bcm2835_clock_emmc_data = { .frac_bits = 8, }; +static const struct bcm2835_clock_data bcm2835_clock_pwm_data = { + .name = "pwm", + .num_mux_parents = ARRAY_SIZE(bcm2835_clock_per_parents), + .parents = bcm2835_clock_per_parents, + .ctl_reg = CM_PWMCTL, + .div_reg = CM_PWMDIV, + .int_bits = 12, + .frac_bits = 12, +}; + struct bcm2835_pll { struct clk_hw hw; struct bcm2835_cprman *cprman; @@ -1148,22 +1158,24 @@ static int bcm2835_clock_is_on(struct clk_hw *hw) static u32 bcm2835_clock_choose_div(struct clk_hw *hw, unsigned long rate, - unsigned long parent_rate) + unsigned long parent_rate, + bool round_up) { struct bcm2835_clock *clock = bcm2835_clock_from_hw(hw); const struct bcm2835_clock_data *data = clock->data; - u32 unused_frac_mask = GENMASK(CM_DIV_FRAC_BITS - data->frac_bits, 0); + u32 unused_frac_mask = + GENMASK(CM_DIV_FRAC_BITS - data->frac_bits, 0) >> 1; u64 temp = (u64)parent_rate << CM_DIV_FRAC_BITS; + u64 rem; u32 div; - do_div(temp, rate); + rem = do_div(temp, rate); div = temp; - /* Round and mask off the unused bits */ - if (unused_frac_mask != 0) { - div += unused_frac_mask >> 1; - div &= ~unused_frac_mask; - } + /* Round up and mask off the unused bits */ + if (round_up && ((div & unused_frac_mask) != 0 || rem != 0)) + div += unused_frac_mask + 1; + div &= ~unused_frac_mask; /* Clamp to the limits. */ div = max(div, unused_frac_mask + 1); @@ -1197,16 +1209,6 @@ static long bcm2835_clock_rate_from_divisor(struct bcm2835_clock *clock, return temp; } -static long bcm2835_clock_round_rate(struct clk_hw *hw, - unsigned long rate, - unsigned long *parent_rate) -{ - struct bcm2835_clock *clock = bcm2835_clock_from_hw(hw); - u32 div = bcm2835_clock_choose_div(hw, rate, *parent_rate); - - return bcm2835_clock_rate_from_divisor(clock, *parent_rate, div); -} - static unsigned long bcm2835_clock_get_rate(struct clk_hw *hw, unsigned long parent_rate) { @@ -1271,20 +1273,82 @@ static int bcm2835_clock_set_rate(struct clk_hw *hw, struct bcm2835_clock *clock = bcm2835_clock_from_hw(hw); struct bcm2835_cprman *cprman = clock->cprman; const struct bcm2835_clock_data *data = clock->data; - u32 div = bcm2835_clock_choose_div(hw, rate, parent_rate); + u32 div = bcm2835_clock_choose_div(hw, rate, parent_rate, false); cprman_write(cprman, data->div_reg, div); return 0; } +static int bcm2835_clock_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + struct bcm2835_clock *clock = bcm2835_clock_from_hw(hw); + struct clk_hw *parent, *best_parent = NULL; + unsigned long rate, best_rate = 0; + unsigned long prate, best_prate = 0; + size_t i; + u32 div; + + /* + * Select parent clock that results in the closest but lower rate + */ + for (i = 0; i < clk_hw_get_num_parents(hw); ++i) { + parent = clk_hw_get_parent_by_index(hw, i); + if (!parent) + continue; + prate = clk_hw_get_rate(parent); + div = bcm2835_clock_choose_div(hw, req->rate, prate, true); + rate = bcm2835_clock_rate_from_divisor(clock, prate, div); + if (rate > best_rate && rate <= req->rate) { + best_parent = parent; + best_prate = prate; + best_rate = rate; + } + } + + if (!best_parent) + return -EINVAL; + + req->best_parent_hw = best_parent; + req->best_parent_rate = best_prate; + + req->rate = best_rate; + + return 0; +} + +static int bcm2835_clock_set_parent(struct clk_hw *hw, u8 index) +{ + struct bcm2835_clock *clock = bcm2835_clock_from_hw(hw); + struct bcm2835_cprman *cprman = clock->cprman; + const struct bcm2835_clock_data *data = clock->data; + u8 src = (index << CM_SRC_SHIFT) & CM_SRC_MASK; + + cprman_write(cprman, data->ctl_reg, src); + return 0; +} + +static u8 bcm2835_clock_get_parent(struct clk_hw *hw) +{ + struct bcm2835_clock *clock = bcm2835_clock_from_hw(hw); + struct bcm2835_cprman *cprman = clock->cprman; + const struct bcm2835_clock_data *data = clock->data; + u32 src = cprman_read(cprman, data->ctl_reg); + + return (src & CM_SRC_MASK) >> CM_SRC_SHIFT; +} + + static const struct clk_ops bcm2835_clock_clk_ops = { .is_prepared = bcm2835_clock_is_on, .prepare = bcm2835_clock_on, .unprepare = bcm2835_clock_off, .recalc_rate = bcm2835_clock_get_rate, .set_rate = bcm2835_clock_set_rate, - .round_rate = bcm2835_clock_round_rate, + .determine_rate = bcm2835_clock_determine_rate, + .set_parent = bcm2835_clock_set_parent, + .get_parent = bcm2835_clock_get_parent, }; static int bcm2835_vpu_clock_is_on(struct clk_hw *hw) @@ -1300,7 +1364,9 @@ static const struct clk_ops bcm2835_vpu_clock_clk_ops = { .is_prepared = bcm2835_vpu_clock_is_on, .recalc_rate = bcm2835_clock_get_rate, .set_rate = bcm2835_clock_set_rate, - .round_rate = bcm2835_clock_round_rate, + .determine_rate = bcm2835_clock_determine_rate, + .set_parent = bcm2835_clock_set_parent, + .get_parent = bcm2835_clock_get_parent, }; static struct clk *bcm2835_register_pll(struct bcm2835_cprman *cprman, @@ -1394,45 +1460,23 @@ static struct clk *bcm2835_register_clock(struct bcm2835_cprman *cprman, { struct bcm2835_clock *clock; struct clk_init_data init; - const char *parent; + const char *parents[1 << CM_SRC_BITS]; + size_t i; /* - * Most of the clock generators have a mux field, so we - * instantiate a generic mux as our parent to handle it. + * Replace our "xosc" references with the oscillator's + * actual name. */ - if (data->num_mux_parents) { - const char *parents[1 << CM_SRC_BITS]; - int i; - - parent = devm_kasprintf(cprman->dev, GFP_KERNEL, - "mux_%s", data->name); - if (!parent) - return NULL; - - /* - * Replace our "xosc" references with the oscillator's - * actual name. - */ - for (i = 0; i < data->num_mux_parents; i++) { - if (strcmp(data->parents[i], "xosc") == 0) - parents[i] = cprman->osc_name; - else - parents[i] = data->parents[i]; - } - - clk_register_mux(cprman->dev, parent, - parents, data->num_mux_parents, - CLK_SET_RATE_PARENT, - cprman->regs + data->ctl_reg, - CM_SRC_SHIFT, CM_SRC_BITS, - 0, &cprman->regs_lock); - } else { - parent = data->parents[0]; + for (i = 0; i < data->num_mux_parents; i++) { + if (strcmp(data->parents[i], "xosc") == 0) + parents[i] = cprman->osc_name; + else + parents[i] = data->parents[i]; } memset(&init, 0, sizeof(init)); - init.parent_names = &parent; - init.num_parents = 1; + init.parent_names = parents; + init.num_parents = data->num_mux_parents; init.name = data->name; init.flags = CLK_IGNORE_UNUSED; @@ -1550,6 +1594,9 @@ static int bcm2835_clk_probe(struct platform_device *pdev) cprman->regs + CM_PERIICTL, CM_GATE_BIT, 0, &cprman->regs_lock); + clks[BCM2835_CLOCK_PWM] = + bcm2835_register_clock(cprman, &bcm2835_clock_pwm_data); + return of_clk_add_provider(dev->of_node, of_clk_src_onecell_get, &cprman->onecell); } |