[RFC PATCH] clk: rockchip: rk3399: support pll setting automatically

Xing Zheng
2016-08-02T13:34:12Z

From: Elaine Zhang <zhangqing-TNX95d0MmH7DzftRWevZcw@public.gmane.org>

The goal is that we can configure the most suitable pll params automatically.

If setting freq is not supported in rockchip_pll_rate_table rk3399_pll_rates[],
we can set pll params automatically.

Signed-off-by: Elaine Zhang <zhangqing-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
Signed-off-by: Xing Zheng <zhengxing-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
---

drivers/clk/rockchip/clk-pll.c | 213 +++++++++++++++++++++++++++++++++++++---
1 file changed, 200 insertions(+), 13 deletions(-)

diff --git a/drivers/clk/rockchip/clk-pll.c b/drivers/clk/rockchip/clk-pll.c
index 35994e8..08979f9 100644
--- a/drivers/clk/rockchip/clk-pll.c
+++ b/drivers/clk/rockchip/clk-pll.c
@@ -23,6 +23,7 @@
#include <linux/clk-provider.h>
#include <linux/regmap.h>
#include <linux/clk.h>
+#include <linux/gcd.h>
#include "clk.h"

#define PLL_MODE_MASK 0x3
@@ -54,6 +55,200 @@ struct rockchip_clk_pll {
#define to_rockchip_clk_pll_nb(nb) \
container_of(nb, struct rockchip_clk_pll, clk_nb)

+#define MHZ (1000UL * 1000UL)
+#define KHZ (1000UL)
+
+/* CLK_PLL_TYPE_RK3066_AUTO type ops */
+#define PLL_FREF_MIN (269 * KHZ)
+#define PLL_FREF_MAX (2200 * MHZ)
+
+#define PLL_FVCO_MIN (440 * MHZ)
+#define PLL_FVCO_MAX (2200 * MHZ)
+
+#define PLL_FOUT_MIN (27500 * KHZ)
+#define PLL_FOUT_MAX (2200 * MHZ)
+
+#define PLL_NF_MAX (4096)
+#define PLL_NR_MAX (64)
+#define PLL_NO_MAX (16)
+
+/* CLK_PLL_TYPE_RK3036/3366/3399_AUTO type ops */
+#define MIN_FOUTVCO_FREQ (800 * MHZ)
+#define MAX_FOUTVCO_FREQ (2000 * MHZ)
+
+static struct rockchip_pll_rate_table auto_table;
+
+static struct rockchip_pll_rate_table *rk_pll_rate_table_get(void)
+{
+ return &auto_table;
+}
+
+static int rockchip_pll_clk_set_postdiv(unsigned long fout_hz,
+ u32 *postdiv1,
+ u32 *postdiv2,
+ u32 *foutvco)
+{
+ unsigned long freq;
+
+ if (fout_hz < MIN_FOUTVCO_FREQ) {
+ for (*postdiv1 = 1; *postdiv1 <= 7; (*postdiv1)++) {
+ for (*postdiv2 = 1; *postdiv2 <= 7; (*postdiv2)++) {
+ freq = fout_hz * (*postdiv1) * (*postdiv2);
+ if (freq >= MIN_FOUTVCO_FREQ &&
+ freq <= MAX_FOUTVCO_FREQ) {
+ *foutvco = freq;
+ return 0;
+ }
+ }
+ pr_err("CANNOT FIND postdiv1/2 to make fout in range from 800M to 2000M,fout = %lu\n",
+ fout_hz);
+ }
+ } else {
+ *postdiv1 = 1;
+ *postdiv2 = 1;
+ }
+ return 0;
+}
+
+static struct rockchip_pll_rate_table *
+rockchip_pll_clk_set_by_auto(struct rockchip_clk_pll *pll,
+ unsigned long fin_hz,
+ unsigned long fout_hz)
+{
+ struct rockchip_pll_rate_table *rate_table = rk_pll_rate_table_get();
+ /* FIXME set postdiv1/2 always 1*/
+ u32 foutvco = fout_hz;
+ u64 fin_64, frac_64;
+ u32 f_frac, postdiv1, postdiv2;
+ unsigned long clk_gcd = 0;
+
+ if (fin_hz == 0 || fout_hz == 0 || fout_hz == fin_hz)
+ return NULL;
+
+ rockchip_pll_clk_set_postdiv(fout_hz, &postdiv1, &postdiv2, &foutvco);
+ rate_table->postdiv1 = postdiv1;
+ rate_table->postdiv2 = postdiv2;
+ rate_table->dsmpd = 1;
+
+ if (fin_hz / MHZ * MHZ == fin_hz && fout_hz / MHZ * MHZ == fout_hz) {
+ fin_hz /= MHZ;
+ foutvco /= MHZ;
+ clk_gcd = gcd(fin_hz, foutvco);
+ rate_table->refdiv = fin_hz / clk_gcd;
+ rate_table->fbdiv = foutvco / clk_gcd;
+
+ rate_table->frac = 0;
+
+ pr_debug("fin = %lu, fout = %lu, clk_gcd = %lu, refdiv = %u, fbdiv = %u, postdiv1 = %u, postdiv2 = %u, frac = %u\n",
+ fin_hz, fout_hz, clk_gcd, rate_table->refdiv,
+ rate_table->fbdiv, rate_table->postdiv1,
+ rate_table->postdiv2, rate_table->frac);
+ } else {
+ pr_debug("frac div running, fin_hz = %lu, fout_hz = %lu, fin_INT_mhz = %lu, fout_INT_mhz = %lu\n",
+ fin_hz, fout_hz,
+ fin_hz / MHZ * MHZ,
+ fout_hz / MHZ * MHZ);
+ pr_debug("frac get postdiv1 = %u, postdiv2 = %u, foutvco = %u\n",
+ rate_table->postdiv1, rate_table->postdiv2, foutvco);
+ clk_gcd = gcd(fin_hz / MHZ, foutvco / MHZ);
+ rate_table->refdiv = fin_hz / MHZ / clk_gcd;
+ rate_table->fbdiv = foutvco / MHZ / clk_gcd;
+ pr_debug("frac get refdiv = %u, fbdiv = %u\n",
+ rate_table->refdiv, rate_table->fbdiv);
+
+ rate_table->frac = 0;
+
+ f_frac = (foutvco % MHZ);
+ fin_64 = fin_hz;
+ do_div(fin_64, (u64)rate_table->refdiv);
+ frac_64 = (u64)f_frac << 24;
+ do_div(frac_64, fin_64);
+ rate_table->frac = (u32)frac_64;
+ if (rate_table->frac > 0)
+ rate_table->dsmpd = 0;
+ pr_debug("frac = %x\n", rate_table->frac);
+ }
+ return rate_table;
+}
+
+static struct rockchip_pll_rate_table *
+rockchip_rk3066_pll_clk_set_by_auto(struct rockchip_clk_pll *pll,
+ unsigned long fin_hz,
+ unsigned long fout_hz)
+{
+ struct rockchip_pll_rate_table *rate_table = rk_pll_rate_table_get();
+ u32 nr, nf, no, nonr;
+ u32 nr_out, nf_out, no_out;
+ u32 n;
+ u32 numerator, denominator;
+ u64 fref, fvco, fout;
+ unsigned long clk_gcd = 0;
+
+ nr_out = PLL_NR_MAX + 1;
+ nf_out = 0;
+ no_out = 0;
+
+ if (fin_hz == 0 || fout_hz == 0 || fout_hz == fin_hz)
+ return NULL;
+
+ clk_gcd = gcd(fin_hz, fout_hz);
+
+ numerator = fout_hz / clk_gcd;
+ denominator = fin_hz / clk_gcd;
+
+ for (n = 1;; n++) {
+ nf = numerator * n;
+ nonr = denominator * n;
+ if (nf > PLL_NF_MAX || nonr > (PLL_NO_MAX * PLL_NR_MAX))
+ break;
+
+ for (no = 1; no <= PLL_NO_MAX; no++) {
+ if (!(no == 1 || !(no % 2)))
+ continue;
+
+ if (nonr % no)
+ continue;
+ nr = nonr / no;
+
+ if (nr > PLL_NR_MAX)
+ continue;
+
+ fref = fin_hz / nr;
+ if (fref < PLL_FREF_MIN || fref > PLL_FREF_MAX)
+ continue;
+
+ fvco = fref * nf;
+ if (fvco < PLL_FVCO_MIN || fvco > PLL_FVCO_MAX)
+ continue;
+
+ fout = fvco / no;
+ if (fout < PLL_FOUT_MIN || fout > PLL_FOUT_MAX)
+ continue;
+
+ /* select the best from all available PLL settings */
+ if ((no > no_out) ||
+ ((no == no_out) && (nr < nr_out))) {
+ nr_out = nr;
+ nf_out = nf;
+ no_out = no;
+ }
+ }
+ }
+
+ /* output the best PLL setting */
+ if ((nr_out <= PLL_NR_MAX) && (no_out > 0)) {
+ if (rate_table->nr && rate_table->nf && rate_table->no) {
+ rate_table->nr = nr_out;
+ rate_table->nf = nf_out;
+ rate_table->no = no_out;
+ }
+ } else {
+ return NULL;
+ }
+
+ return rate_table;
+}
+
static const struct rockchip_pll_rate_table *rockchip_get_pll_settings(
struct rockchip_clk_pll *pll, unsigned long rate)
{
@@ -65,24 +260,16 @@ static const struct rockchip_pll_rate_table *rockchip_get_pll_settings(
return &rate_table[i];
}

- return NULL;
+ if (pll->type == pll_rk3066)
+ return rockchip_rk3066_pll_clk_set_by_auto(pll, 24 * MHZ, rate);
+ else
+ return rockchip_pll_clk_set_by_auto(pll, 24 * MHZ, rate);
}

static long rockchip_pll_round_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_table = pll->rate_table;
- int i;
-
- /* Assumming rate_table is in descending order */
- for (i = 0; i < pll->rate_count; i++) {
- if (drate >= rate_table[i].rate)
- return rate_table[i].rate;
- }
-
- /* return minimum supported value */
- return rate_table[i - 1].rate;
+ return drate;
}

/*
--
1.7.9.5