[U-Boot] [PATCH v3 41/66] rockchip: clk: rk3368: implement DPLL (DRAM PLL) support

Philipp Tomsich
2017-07-28T19:22:13Z

To implement a TPL stage (incl. its DRAM controller setup) for the
RK3368, we'll want to configure the DPLL (DRAM PLL).

This commit implements setting the DPLL (CLK_DDR) and provides PLL
configuration details for the common DRAM operating speeds found on
RK3368 boards.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>

Reviewed-by: Simon Glass <sjg@chromium.org>
---

Changes in v3: None
Changes in v2: None

drivers/clk/rockchip/clk_rk3368.c | 35 +++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)

diff --git a/drivers/clk/rockchip/clk_rk3368.c b/drivers/clk/rockchip/clk_rk3368.c
index d05be72..33d2946 100644
--- a/drivers/clk/rockchip/clk_rk3368.c
+++ b/drivers/clk/rockchip/clk_rk3368.c
@@ -250,6 +250,37 @@ static ulong rk3368_clk_get_rate(struct clk *clk)
return rate;
}

+static ulong rk3368_ddr_set_clk(struct rk3368_cru *cru, ulong set_rate)
+{
+ const struct pll_div *dpll_cfg = NULL;
+ const ulong MHz = 1000000;
+
+ /* Fout = ((Fin /NR) * NF )/ NO */
+ static const struct pll_div dpll_1200 =
+ PLL_DIVISORS(1200 * MHz, 1, 1);
+ static const struct pll_div dpll_1332 =
+ PLL_DIVISORS(1332 * MHz, 2, 1);
+ static const struct pll_div dpll_1600 =
+ PLL_DIVISORS(1600 * MHz, 3, 2);
+
+ switch (set_rate) {
+ case 1200*MHz:
+ dpll_cfg = &dpll_1200;
+ break;
+ case 1332*MHz:
+ dpll_cfg = &dpll_1332;
+ break;
+ case 1600*MHz:
+ dpll_cfg = &dpll_1600;
+ break;
+ default:
+ error("Unsupported SDRAM frequency!,%ld\n", set_rate);
+ }
+ rkclk_set_pll(cru, DPLL, dpll_cfg);
+
+ return set_rate;
+}
+
static ulong rk3368_clk_set_rate(struct clk *clk, ulong rate)
{
struct rk3368_clk_priv *priv = dev_get_priv(clk->dev);
@@ -257,6 +288,10 @@ static ulong rk3368_clk_set_rate(struct clk *clk, ulong rate)

debug("%s id:%ld rate:%ld\n", __func__, clk->id, rate);
switch (clk->id) {
+ case CLK_DDR:
+ ret = rk3368_ddr_set_clk(priv->cru, rate);
+ break;
+
case SCLK_SDMMC:
case SCLK_EMMC:
ret = rk3368_mmc_set_clk(priv->cru, clk->id, rate);
--
2.1.4