diff options
Diffstat (limited to 'drivers/clk')
| -rw-r--r-- | drivers/clk/ti/fapll.c | 134 |
1 files changed, 132 insertions, 2 deletions
diff --git a/drivers/clk/ti/fapll.c b/drivers/clk/ti/fapll.c index 97138c106a67..fc06abe5eaaf 100644 --- a/drivers/clk/ti/fapll.c +++ b/drivers/clk/ti/fapll.c @@ -12,6 +12,7 @@ #include <linux/clk-provider.h> #include <linux/delay.h> #include <linux/err.h> +#include <linux/math64.h> #include <linux/of.h> #include <linux/of_address.h> #include <linux/clk/ti.h> @@ -47,6 +48,8 @@ /* Synthesizer frequency register */ #define SYNTH_LDFREQ BIT(31) +#define SYNTH_PHASE_K 8 +#define SYNTH_MAX_INT_DIV 0xf #define SYNTH_MAX_DIV_M 0xff struct fapll_data { @@ -204,7 +207,7 @@ static unsigned long ti_fapll_synth_recalc_rate(struct clk_hw *hw, /* * Synth frequency integer and fractional divider. * Note that the phase output K is 8, so the result needs - * to be multiplied by 8. + * to be multiplied by SYNTH_PHASE_K. */ if (synth->freq) { u32 v, synth_int_div, synth_frac_div, synth_div_freq; @@ -215,7 +218,7 @@ static unsigned long ti_fapll_synth_recalc_rate(struct clk_hw *hw, synth_div_freq = (synth_int_div * 10000000) + synth_frac_div; rate *= 10000000; do_div(rate, synth_div_freq); - rate *= 8; + rate *= SYNTH_PHASE_K; } /* Synth post-divider M */ @@ -224,11 +227,138 @@ static unsigned long ti_fapll_synth_recalc_rate(struct clk_hw *hw, return DIV_ROUND_UP_ULL(rate, synth_div_m); } +static unsigned long ti_fapll_synth_get_frac_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct fapll_synth *synth = to_synth(hw); + unsigned long current_rate, frac_rate; + u32 post_div_m; + + current_rate = ti_fapll_synth_recalc_rate(hw, parent_rate); + post_div_m = readl_relaxed(synth->div) & SYNTH_MAX_DIV_M; + frac_rate = current_rate * post_div_m; + + return frac_rate; +} + +static u32 ti_fapll_synth_set_frac_rate(struct fapll_synth *synth, + unsigned long rate, + unsigned long parent_rate) +{ + u32 post_div_m, synth_int_div = 0, synth_frac_div = 0, v; + + post_div_m = DIV_ROUND_UP_ULL((u64)parent_rate * SYNTH_PHASE_K, rate); + post_div_m = post_div_m / SYNTH_MAX_INT_DIV; + if (post_div_m > SYNTH_MAX_DIV_M) + return -EINVAL; + if (!post_div_m) + post_div_m = 1; + + for (; post_div_m < SYNTH_MAX_DIV_M; post_div_m++) { + synth_int_div = DIV_ROUND_UP_ULL((u64)parent_rate * + SYNTH_PHASE_K * + 10000000, + rate * post_div_m); + synth_frac_div = synth_int_div % 10000000; + synth_int_div /= 10000000; + + if (synth_int_div <= SYNTH_MAX_INT_DIV) + break; + } + + if (synth_int_div > SYNTH_MAX_INT_DIV) + return -EINVAL; + + v = readl_relaxed(synth->freq); + v &= ~0x1fffffff; + v |= (synth_int_div & SYNTH_MAX_INT_DIV) << 24; + v |= (synth_frac_div & 0xffffff); + v |= SYNTH_LDFREQ; + writel_relaxed(v, synth->freq); + + return post_div_m; +} + +static long ti_fapll_synth_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct fapll_synth *synth = to_synth(hw); + struct fapll_data *fd = synth->fd; + unsigned long r; + + if (ti_fapll_clock_is_bypass(fd) || !synth->div || !rate) + return -EINVAL; + + /* Only post divider m available with no fractional divider? */ + if (!synth->freq) { + unsigned long frac_rate; + u32 synth_post_div_m; + + frac_rate = ti_fapll_synth_get_frac_rate(hw, *parent_rate); + synth_post_div_m = DIV_ROUND_UP(frac_rate, rate); + r = DIV_ROUND_UP(frac_rate, synth_post_div_m); + goto out; + } + + r = *parent_rate * SYNTH_PHASE_K; + if (rate > r) + goto out; + + r = DIV_ROUND_UP_ULL(r, SYNTH_MAX_INT_DIV * SYNTH_MAX_DIV_M); + if (rate < r) + goto out; + + r = rate; +out: + return r; +} + +static int ti_fapll_synth_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct fapll_synth *synth = to_synth(hw); + struct fapll_data *fd = synth->fd; + unsigned long frac_rate, post_rate = 0; + u32 post_div_m = 0, v; + + if (ti_fapll_clock_is_bypass(fd) || !synth->div || !rate) + return -EINVAL; + + /* Produce the rate with just post divider M? */ + frac_rate = ti_fapll_synth_get_frac_rate(hw, parent_rate); + if (frac_rate < rate) { + if (!synth->freq) + return -EINVAL; + } else { + post_div_m = DIV_ROUND_UP(frac_rate, rate); + if (post_div_m && (post_div_m <= SYNTH_MAX_DIV_M)) + post_rate = DIV_ROUND_UP(frac_rate, post_div_m); + if (!synth->freq && !post_rate) + return -EINVAL; + } + + /* Need to recalculate the fractional divider? */ + if ((post_rate != rate) && synth->freq) + post_div_m = ti_fapll_synth_set_frac_rate(synth, + rate, + parent_rate); + + v = readl_relaxed(synth->div); + v &= ~SYNTH_MAX_DIV_M; + v |= post_div_m; + v |= SYNTH_LDMDIV1; + writel_relaxed(v, synth->div); + + return 0; +} + static struct clk_ops ti_fapll_synt_ops = { .enable = ti_fapll_synth_enable, .disable = ti_fapll_synth_disable, .is_enabled = ti_fapll_synth_is_enabled, .recalc_rate = ti_fapll_synth_recalc_rate, + .round_rate = ti_fapll_synth_round_rate, + .set_rate = ti_fapll_synth_set_rate, }; static struct clk * __init ti_fapll_synth_setup(struct fapll_data *fd, |
