On Tue, 2015-01-20 at 14:03 +0200, Igal.Liberman wrote:

+static u8 get_fm_clk_parent(struct clk_hw *hw)
+{
+	struct ccsr_guts __iomem *guts_regs = NULL;
+	struct device_node *guts;
+	uint32_t reg = 0;
+	int clk_src = 0;
+	int fm_clk_select = -EINVAL;
+	int fm_id = 0;
+
+	guts = of_find_matching_node(NULL, guts_device_ids);
+	if (!guts) {
+		pr_err("could not find GUTS node\n");
+		return -EINVAL;
+	}

Error message lacks context (here and elsewhere).

Why are you going this on demand rather than in an init function
(specifically, a CLK_OF_DECLARE)?  You should not register this clock
handler in the first place if the hardware doesn't exist.

-EINVAL doesn't fit in u8.  Neither would the more appropriate -ENODEV.

+	guts_regs = of_iomap(guts, 0);
+	of_node_put(guts);
+	if (!guts_regs) {
+		pr_err("ioremap of GUTS node failed\n");
+		return -EINVAL;
+	}
+
+	if (!strcmp(__clk_get_name(hw->clk), "fm1-clk"))
+		fm_id = 1;
+
+	/* The FM clock provider is SoC dependent and it's determened by the

determined

+	 * reset configuration word (RCW). We need to map the RCW options to
+	 * the order of the providers in the device tree.
+	 * This code makes assumptions about the clock provider order:
+	 * In the PXXXX family:
+	 *	0 - platform clock/2
+	 *	1 - PLLx /2
+	 *	2 - PLLx /4 (if possible).
+	 * In B/T family:
+	 *	The same order in which the clock providers are described in
+	 *	the Reference Manual, starting from 0.

This belongs in a device tree binding document and should not
incorporate portions of the reference manual by reference -- what if a
new version of the reference manual changes the order in which clock
providers are described?  Or do you mean that the order corresponds to a
register value?

+	 *
+	 * In a case of only one possible provider, the index is 0.
+	 */
+
+	if (of_device_is_compatible(guts, "fsl,p1023-guts") ||
+		of_device_is_compatible(guts, "fsl,t1040-device-config"))
+		/* P1023 and T1040 have only one optional clock source */
+		fm_clk_select = 0;
+	else if (of_device_is_compatible(guts, "fsl,p2041-device-config") ||
+		 of_device_is_compatible(guts, "fsl,p3041-device-config") ||
+		 of_device_is_compatible(guts, "fsl,p4080-device-config")) {
+		/* Read RCW*/

/* Read RCW */

Where is the binding for this node?

-Scott