[RESEND PATCH v2 03/13] drivers: clk: st: Add fs660c32 synthesizer algorithm

Gabriel Fernandez
2016-06-16T09:20:23Z

Use an algorithm instead of a table to compute clocks for fs660c32
synthesizer.
During a video playback we need to adjust audio & video frequencies.
A table can't cover all HDMI resolutions and audio adjustment.

Signed-off-by: Gabriel Fernandez <gabriel.fernandez@linaro.org>
---
drivers/clk/st/clkgen-fsyn.c | 180 ++++++++++++++++++++++++++-----------------
1 file changed, 111 insertions(+), 69 deletions(-)

diff --git a/drivers/clk/st/clkgen-fsyn.c b/drivers/clk/st/clkgen-fsyn.c
index 53fd047..765f0f2 100644
--- a/drivers/clk/st/clkgen-fsyn.c
+++ b/drivers/clk/st/clkgen-fsyn.c
@@ -42,40 +42,6 @@ struct stm_fs {
unsigned long nsdiv;
};

-static const struct stm_fs fs660c32_rtbl[] = {
- { .mdiv = 0x14, .pe = 0x376b, .sdiv = 0x4, .nsdiv = 1 }, /* 25.175 MHz */
- { .mdiv = 0x14, .pe = 0x30c3, .sdiv = 0x4, .nsdiv = 1 }, /* 25.200 MHz */
- { .mdiv = 0x10, .pe = 0x71c7, .sdiv = 0x4, .nsdiv = 1 }, /* 27.000 MHz */
- { .mdiv = 0x00, .pe = 0x47af, .sdiv = 0x3, .nsdiv = 0 }, /* 27.027 MHz */
- { .mdiv = 0x0e, .pe = 0x4e1a, .sdiv = 0x4, .nsdiv = 1 }, /* 28.320 MHz */
- { .mdiv = 0x0b, .pe = 0x534d, .sdiv = 0x4, .nsdiv = 1 }, /* 30.240 MHz */
- { .mdiv = 0x17, .pe = 0x6fbf, .sdiv = 0x2, .nsdiv = 0 }, /* 31.500 MHz */
- { .mdiv = 0x01, .pe = 0x0, .sdiv = 0x4, .nsdiv = 1 }, /* 40.000 MHz */
- { .mdiv = 0x15, .pe = 0x2aab, .sdiv = 0x3, .nsdiv = 1 }, /* 49.500 MHz */
- { .mdiv = 0x14, .pe = 0x6666, .sdiv = 0x3, .nsdiv = 1 }, /* 50.000 MHz */
- { .mdiv = 0x1d, .pe = 0x395f, .sdiv = 0x1, .nsdiv = 0 }, /* 57.284 MHz */
- { .mdiv = 0x08, .pe = 0x4ec5, .sdiv = 0x3, .nsdiv = 1 }, /* 65.000 MHz */
- { .mdiv = 0x05, .pe = 0x1770, .sdiv = 0x3, .nsdiv = 1 }, /* 71.000 MHz */
- { .mdiv = 0x03, .pe = 0x4ba7, .sdiv = 0x3, .nsdiv = 1 }, /* 74.176 MHz */
- { .mdiv = 0x0f, .pe = 0x3426, .sdiv = 0x1, .nsdiv = 0 }, /* 74.250 MHz */
- { .mdiv = 0x0e, .pe = 0x7777, .sdiv = 0x1, .nsdiv = 0 }, /* 75.000 MHz */
- { .mdiv = 0x01, .pe = 0x4053, .sdiv = 0x3, .nsdiv = 1 }, /* 78.800 MHz */
- { .mdiv = 0x09, .pe = 0x15b5, .sdiv = 0x1, .nsdiv = 0 }, /* 85.500 MHz */
- { .mdiv = 0x1b, .pe = 0x3f19, .sdiv = 0x2, .nsdiv = 1 }, /* 88.750 MHz */
- { .mdiv = 0x10, .pe = 0x71c7, .sdiv = 0x2, .nsdiv = 1 }, /* 108.000 MHz */
- { .mdiv = 0x00, .pe = 0x47af, .sdiv = 0x1, .nsdiv = 0 }, /* 108.108 MHz */
- { .mdiv = 0x0c, .pe = 0x3118, .sdiv = 0x2, .nsdiv = 1 }, /* 118.963 MHz */
- { .mdiv = 0x0c, .pe = 0x2f54, .sdiv = 0x2, .nsdiv = 1 }, /* 119.000 MHz */
- { .mdiv = 0x07, .pe = 0xe39, .sdiv = 0x2, .nsdiv = 1 }, /* 135.000 MHz */
- { .mdiv = 0x03, .pe = 0x4ba7, .sdiv = 0x2, .nsdiv = 1 }, /* 148.352 MHz */
- { .mdiv = 0x0f, .pe = 0x3426, .sdiv = 0x0, .nsdiv = 0 }, /* 148.500 MHz */
- { .mdiv = 0x03, .pe = 0x4ba7, .sdiv = 0x1, .nsdiv = 1 }, /* 296.704 MHz */
- { .mdiv = 0x03, .pe = 0x471c, .sdiv = 0x1, .nsdiv = 1 }, /* 297.000 MHz */
- { .mdiv = 0x00, .pe = 0x295f, .sdiv = 0x1, .nsdiv = 1 }, /* 326.700 MHz */
- { .mdiv = 0x1f, .pe = 0x3633, .sdiv = 0x0, .nsdiv = 1 }, /* 333.000 MHz */
- { .mdiv = 0x1c, .pe = 0x0, .sdiv = 0x0, .nsdiv = 1 }, /* 352.000 Mhz */
-};
-
struct clkgen_quadfs_data {
bool reset_present;
bool bwfilter_present;
@@ -99,8 +65,7 @@ struct clkgen_quadfs_data {
struct clkgen_field nsdiv[QUADFS_MAX_CHAN];

const struct clk_ops *pll_ops;
- const struct stm_fs *rtbl;
- u8 rtbl_cnt;
+ int (*get_params)(unsigned long, unsigned long, struct stm_fs *);
int (*get_rate)(unsigned long , const struct stm_fs *,
unsigned long *);
};
@@ -108,6 +73,8 @@ struct clkgen_quadfs_data {
static const struct clk_ops st_quadfs_pll_c32_ops;
static const struct clk_ops st_quadfs_fs660c32_ops;

+static int clk_fs660c32_dig_get_params(unsigned long input,
+ unsigned long output, struct stm_fs *fs);
static int clk_fs660c32_dig_get_rate(unsigned long, const struct stm_fs *,
unsigned long *);

@@ -149,8 +116,7 @@ static const struct clkgen_quadfs_data st_fs660c32_C = {
.powerup_polarity = 1,
.standby_polarity = 1,
.pll_ops = &st_quadfs_pll_c32_ops,
- .rtbl = fs660c32_rtbl,
- .rtbl_cnt = ARRAY_SIZE(fs660c32_rtbl),
+ .get_params = clk_fs660c32_dig_get_params,
.get_rate = clk_fs660c32_dig_get_rate,
};

@@ -192,8 +158,7 @@ static const struct clkgen_quadfs_data st_fs660c32_D = {
.powerup_polarity = 1,
.standby_polarity = 1,
.pll_ops = &st_quadfs_pll_c32_ops,
- .rtbl = fs660c32_rtbl,
- .rtbl_cnt = ARRAY_SIZE(fs660c32_rtbl),
+ .get_params = clk_fs660c32_dig_get_params,
.get_rate = clk_fs660c32_dig_get_rate,};

/**
@@ -620,6 +585,107 @@ static int clk_fs660c32_dig_get_rate(unsigned long input,
return 0;
}

+
+static int clk_fs660c32_get_pe(int m, int si, unsigned long *deviation,
+ signed long input, unsigned long output, uint64_t *p,
+ struct stm_fs *fs)
+{
+ unsigned long new_freq, new_deviation;
+ struct stm_fs fs_tmp;
+ uint64_t val;
+
+ val = (uint64_t)output << si;
+
+ *p = (uint64_t)input * P20 - (32LL + (uint64_t)m) * val * (P20 / 32LL);
+
+ *p = div64_u64(*p, val);
+
+ if (*p > 32767LL)
+ return 1;
+
+ fs_tmp.mdiv = (unsigned long) m;
+ fs_tmp.pe = (unsigned long)*p;
+ fs_tmp.sdiv = si;
+ fs_tmp.nsdiv = 1;
+
+ clk_fs660c32_dig_get_rate(input, &fs_tmp, &new_freq);
+
+ new_deviation = abs(output - new_freq);
+
+ if (new_deviation < *deviation) {
+ fs->mdiv = m;
+ fs->pe = (unsigned long)*p;
+ fs->sdiv = si;
+ fs->nsdiv = 1;
+ *deviation = new_deviation;
+ }
+ return 0;
+}
+
+static int clk_fs660c32_dig_get_params(unsigned long input,
+ unsigned long output, struct stm_fs *fs)
+{
+ int si; /* sdiv_reg (8 downto 0) */
+ int m; /* md value */
+ unsigned long new_freq, new_deviation;
+ /* initial condition to say: "infinite deviation" */
+ unsigned long deviation = ~0;
+ uint64_t p, p1, p2; /* pe value */
+ int r1, r2;
+
+ struct stm_fs fs_tmp;
+
+ for (si = 0; (si <= 8) && deviation; si++) {
+
+ /* Boundary test to avoid useless iteration */
+ r1 = clk_fs660c32_get_pe(0, si, &deviation,
+ input, output, &p1, fs);
+ r2 = clk_fs660c32_get_pe(31, si, &deviation,
+ input, output, &p2, fs);
+
+ /* No solution */
+ if (r1 && r2 && (p1 > p2))
+ continue;
+
+ /* Try to find best deviation */
+ for (m = 1; (m < 31) && deviation; m++)
+ clk_fs660c32_get_pe(m, si, &deviation,
+ input, output, &p, fs);
+
+ }
+
+ if (deviation == ~0) /* No solution found */
+ return -1;
+
+ /* pe fine tuning if deviation not 0: +/- 2 around computed pe value */
+ if (deviation) {
+ fs_tmp.mdiv = fs->mdiv;
+ fs_tmp.sdiv = fs->sdiv;
+ fs_tmp.nsdiv = fs->nsdiv;
+
+ if (fs->pe > 2)
+ p2 = fs->pe - 2;
+ else
+ p2 = 0;
+
+ for (; p2 < 32768ll && (p2 <= (fs->pe + 2)); p2++) {
+ fs_tmp.pe = (unsigned long)p2;
+
+ clk_fs660c32_dig_get_rate(input, &fs_tmp, &new_freq);
+
+ new_deviation = abs(output - new_freq);
+
+ /* Check if this is a better solution */
+ if (new_deviation < deviation) {
+ fs->pe = (unsigned long)p2;
+ deviation = new_deviation;
+
+ }
+ }
+ }
+ return 0;
+}
+
static int quadfs_fsynt_get_hw_value_for_recalc(struct st_clk_quadfs_fsynth *fs,
struct stm_fs *params)
{
@@ -655,38 +721,14 @@ static long quadfs_find_best_rate(struct clk_hw *hw, unsigned long drate,
struct st_clk_quadfs_fsynth *fs = to_quadfs_fsynth(hw);
int (*clk_fs_get_rate)(unsigned long ,
const struct stm_fs *, unsigned long *);
- struct stm_fs prev_params;
- unsigned long prev_rate, rate = 0;
- unsigned long diff_rate, prev_diff_rate = ~0;
- int index;
+ int (*clk_fs_get_params)(unsigned long, unsigned long, struct stm_fs *);
+ unsigned long rate = 0;

clk_fs_get_rate = fs->data->get_rate;
+ clk_fs_get_params = fs->data->get_params;

- for (index = 0; index < fs->data->rtbl_cnt; index++) {
- prev_rate = rate;
-
- *params = fs->data->rtbl[index];
- prev_params = *params;
-
- clk_fs_get_rate(prate, &fs->data->rtbl[index], &rate);
-
- diff_rate = abs(drate - rate);
-
- if (diff_rate > prev_diff_rate) {
- rate = prev_rate;
- *params = prev_params;
- break;
- }
-
- prev_diff_rate = diff_rate;
-
- if (drate == rate)
- return rate;
- }
-
-
- if (index == fs->data->rtbl_cnt)
- *params = prev_params;
+ if (!clk_fs_get_params(prate, drate, params))
+ clk_fs_get_rate(prate, params, &rate);

return rate;
}
--
1.9.1