tegra: Add functions to access low-level Osc/PLL details

Add clock_ll_read_pll() to read PLL parameters and clock_get_osc_bypass()
to find out if the Oscillator is bypassed. These are needed by warmboot.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>

arch/arm/include/asm/arch-tegra2/clk_rst.h

@@ -117,6 +117,7 @@ struct clk_rst_ctlr {
 #define PLL_CPCON_MASK		(15U << PLL_CPCON_SHIFT)
 
 #define PLL_LFCON_SHIFT		4
+#define PLL_LFCON_MASK		(15U << PLL_LFCON_SHIFT)
 
 #define PLLU_VCO_FREQ_SHIFT	20
 #define PLLU_VCO_FREQ_MASK	(1U << PLLU_VCO_FREQ_SHIFT)
@@ -124,6 +125,8 @@ struct clk_rst_ctlr {
 /* CLK_RST_CONTROLLER_OSC_CTRL_0 */
 #define OSC_FREQ_SHIFT		30
 #define OSC_FREQ_MASK		(3U << OSC_FREQ_SHIFT)
+#define OSC_XOBP_SHIFT		1
+#define OSC_XOBP_MASK		(1U << OSC_XOBP_SHIFT)
 
 /*
  * CLK_RST_CONTROLLER_CLK_SOURCE_x_OUT_0 - the mask here is normally 8 bits

arch/arm/include/asm/arch-tegra2/clock.h

@@ -210,6 +210,21 @@ enum clock_osc_freq clock_get_osc_freq(void);
 unsigned long clock_start_pll(enum clock_id id, u32 divm, u32 divn,
 		u32 divp, u32 cpcon, u32 lfcon);
 
+/**
+ * Read low-level parameters of a PLL.
+ *
+ * @param id	clock id to read (note: USB is not supported)
+ * @param divm	returns input divider
+ * @param divn	returns feedback divider
+ * @param divp	returns post divider 2^n
+ * @param cpcon	returns charge pump setup control
+ * @param lfcon	returns loop filter setup control
+ *
+ * @returns 0 if ok, -1 on error (invalid clock id)
+ */
+int clock_ll_read_pll(enum clock_id clkid, u32 *divm, u32 *divn,
+		      u32 *divp, u32 *cpcon, u32 *lfcon);
+
 /*
  * Enable a clock
  *
@@ -368,6 +383,13 @@ void clock_ll_start_uart(enum periph_id periph_id);
  */
 enum periph_id clock_decode_periph_id(const void *blob, int node);
 
+/**
+ * Checks if the oscillator bypass is enabled (XOBP bit)
+ *
+ * @return 1 if bypass is enabled, 0 if not
+ */
+int clock_get_osc_bypass(void);
+
 /*
  * Checks that clocks are valid and prints a warning if not
  *