clk: meson: add axg misc bit to the mpll driver

On axg, the rate of the mpll is stuck as if sdm value was 4 and could not
change (expect for mpll2 strangely). Looking at the vendor kernel, it
turns out a new magic bit from the undocumented HHI_PLL_TOP_MISC register
is required.

Setting this bit solves the problem and the mpll rates are back to normal

Fixes: 78b4af312f ("clk: meson-axg: add clock controller drivers")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>

drivers/clk/meson/axg.c

@@ -292,6 +292,11 @@ static struct meson_clk_mpll axg_mpll0 = {
 		.shift   = 25,
 		.width	 = 1,
 	},
+	.misc = {
+		.reg_off = HHI_PLL_TOP_MISC,
+		.shift   = 0,
+		.width	 = 1,
+	},
 	.lock = &meson_clk_lock,
 	.hw.init = &(struct clk_init_data){
 		.name = "mpll0",
@@ -322,6 +327,11 @@ static struct meson_clk_mpll axg_mpll1 = {
 		.shift   = 14,
 		.width	 = 1,
 	},
+	.misc = {
+		.reg_off = HHI_PLL_TOP_MISC,
+		.shift   = 1,
+		.width	 = 1,
+	},
 	.lock = &meson_clk_lock,
 	.hw.init = &(struct clk_init_data){
 		.name = "mpll1",
@@ -352,6 +362,11 @@ static struct meson_clk_mpll axg_mpll2 = {
 		.shift   = 14,
 		.width	 = 1,
 	},
+	.misc = {
+		.reg_off = HHI_PLL_TOP_MISC,
+		.shift   = 2,
+		.width	 = 1,
+	},
 	.lock = &meson_clk_lock,
 	.hw.init = &(struct clk_init_data){
 		.name = "mpll2",
@@ -382,6 +397,11 @@ static struct meson_clk_mpll axg_mpll3 = {
 		.shift   = 0,
 		.width	 = 1,
 	},
+	.misc = {
+		.reg_off = HHI_PLL_TOP_MISC,
+		.shift   = 3,
+		.width	 = 1,
+	},
 	.lock = &meson_clk_lock,
 	.hw.init = &(struct clk_init_data){
 		.name = "mpll3",

drivers/clk/meson/clk-mpll.c

@@ -173,6 +173,13 @@ static int mpll_set_rate(struct clk_hw *hw,
 	reg = PARM_SET(p->width, p->shift, reg, n2);
 	writel(reg, mpll->base + p->reg_off);
 
+	p = &mpll->misc;
+	if (p->width != 0) {
+		reg = readl(mpll->base + p->reg_off);
+		reg = PARM_SET(p->width, p->shift, reg, 1);
+		writel(reg, mpll->base + p->reg_off);
+	}
+
 	if (mpll->lock)
 		spin_unlock_irqrestore(mpll->lock, flags);
 	else

drivers/clk/meson/clkc.h

@@ -121,6 +121,7 @@ struct meson_clk_mpll {
 	struct parm n2;
 	struct parm en;
 	struct parm ssen;
+	struct parm misc;
 	spinlock_t *lock;
 };