tegra20: add clock_set_pllout function

Common practice on Tegra 2 boards is to use the pllp_out4 FO
to generate the ULPI reference clock. For this to work we have
to override the default hardware generated output divider.

This function adds a clean way to do so.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Tom Warren <twarren@nvidia.com>

2 files changed, 39 insertions, 1 deletions

diff --git a/arch/arm/cpu/tegra20-common/clock.c b/arch/arm/cpu/tegra20-common/clock.c
index a670b07..12987a6 100644
--- a/arch/arm/cpu/tegra20-common/clock.c
+++ b/arch/arm/cpu/tegra20-common/clock.c
@@ -396,6 +396,16 @@ static s8 periph_id_to_internal_id[PERIPH_ID_COUNT] = {
 	NONE(CRAM2),
 };
 
+/* number of clock outputs of a PLL */
+static const u8 pll_num_clkouts[] = {
+	1,	/* PLLC */
+	1,	/* PLLM */
+	4,	/* PLLP */
+	1,	/* PLLA */
+	0,	/* PLLU */
+	0,	/* PLLD */
+};
+
 /*
  * Get the oscillator frequency, from the corresponding hardware configuration
  * field.
@@ -604,6 +614,34 @@ unsigned long clock_get_periph_rate(enum periph_id periph_id,
 		(readl(reg) & OUT_CLK_DIVISOR_MASK) >> OUT_CLK_DIVISOR_SHIFT);
 }
 
+int clock_set_pllout(enum clock_id clkid, enum pll_out_id pllout, unsigned rate)
+{
+	struct clk_pll *pll = get_pll(clkid);
+	int data = 0, div = 0, offset = 0;
+
+	if (!clock_id_is_pll(clkid))
+		return -1;
+
+	if (pllout + 1 > pll_num_clkouts[clkid])
+		return -1;
+
+	div = clk_get_divider(8, pll_rate[clkid], rate);
+
+	if (div < 0)
+		return -1;
+
+	/* out2 and out4 are in the high part of the register */
+	if (pllout == PLL_OUT2 || pllout == PLL_OUT4)
+		offset = 16;
+
+	data = (div << PLL_OUT_RATIO_SHIFT) |
+			PLL_OUT_OVRRIDE | PLL_OUT_CLKEN | PLL_OUT_RSTN;
+	clrsetbits_le32(&pll->pll_out[pllout >> 1],
+			PLL_OUT_RATIO_MASK << offset, data << offset);
+
+	return 0;
+}
+
 /**
  * Find the best available 7.1 format divisor given a parent clock rate and
  * required child clock rate. This function assumes that a second-stage
diff --git a/arch/arm/cpu/tegra20-common/warmboot_avp.c b/arch/arm/cpu/tegra20-common/warmboot_avp.c
index bc6281d..bc46606 100644
--- a/arch/arm/cpu/tegra20-common/warmboot_avp.c
+++ b/arch/arm/cpu/tegra20-common/warmboot_avp.c
@@ -214,7 +214,7 @@ void wb_start(void)
 
 	reg = PLLM_OUT1_RSTN_RESET_DISABLE | PLLM_OUT1_CLKEN_ENABLE |
 	      PLLM_OUT1_RATIO_VAL_8;
-	writel(reg, &clkrst->crc_pll[CLOCK_ID_MEMORY].pll_out);
+	writel(reg, &clkrst->crc_pll[CLOCK_ID_MEMORY].pll_out[0]);
 
 	reg = SCLK_SWAKE_FIQ_SRC_PLLM_OUT1 | SCLK_SWAKE_IRQ_SRC_PLLM_OUT1 |
 	      SCLK_SWAKE_RUN_SRC_PLLM_OUT1 | SCLK_SWAKE_IDLE_SRC_PLLM_OUT1 |