OMAP2 clock: dynamically allocate CPUFreq frequency table

Dynamically allocate the CPUFreq frequency table on OMAP2xxx chips.
This fixes some compilation problems, since the kernel may not know
what chip it is running on until boot-time.  This also reduces the size
of the CPUFreq frequency table.

Problem originally reported by Felipe Balbi <felipe.balbi@nokia.com>.
Thanks also for comments on the patch from Felipe and Kevin.
Signed-off-by: NPaul Walmsley <paul@pwsan.com>
Cc: Felipe Balbi <felipe.balbi@nokia.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>

arch/arm/mach-omap2/clock2xxx.c

@@ -449,14 +449,16 @@ int omap2_select_table_rate(struct clk *clk, unsigned long rate)
 #ifdef CONFIG_CPU_FREQ
 /*
  * Walk PRCM rate table and fillout cpufreq freq_table
+ * XXX This should be replaced by an OPP layer in the near future
  */
-static struct cpufreq_frequency_table freq_table[ARRAY_SIZE(rate_table)];
+static struct cpufreq_frequency_table *freq_table;
 
 void omap2_clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
 {
-	struct prcm_config *prcm;
+	const struct prcm_config *prcm;
 	long sys_ck_rate;
 	int i = 0;
+	int tbl_sz = 0;
 
 	sys_ck_rate = clk_get_rate(sclk);
 
@@ -470,22 +472,55 @@ void omap2_clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
 		if (prcm->dpll_speed == prcm->xtal_speed)
 			continue;
 
-		freq_table[i].index = i;
-		freq_table[i].frequency = prcm->mpu_speed / 1000;
-		i++;
+		tbl_sz++;
 	}
 
-	if (i == 0) {
-		printk(KERN_WARNING "%s: failed to initialize frequency "
-		       "table\n", __func__);
+	/*
+	 * XXX Ensure that we're doing what CPUFreq expects for this error
+	 * case and the following one
+	 */
+	if (tbl_sz == 0) {
+		pr_warning("%s: no matching entries in rate_table\n",
+			   __func__);
 		return;
 	}
 
+	/* Include the CPUFREQ_TABLE_END terminator entry */
+	tbl_sz++;
+
+	freq_table = kzalloc(sizeof(struct cpufreq_frequency_table) * tbl_sz,
+			     GFP_ATOMIC);
+	if (!freq_table) {
+		pr_err("%s: could not kzalloc frequency table\n", __func__);
+		return;
+	}
+
+	for (prcm = rate_table; prcm->mpu_speed; prcm++) {
+		if (!(prcm->flags & cpu_mask))
+			continue;
+		if (prcm->xtal_speed != sys_ck_rate)
+			continue;
+
+		/* don't put bypass rates in table */
+		if (prcm->dpll_speed == prcm->xtal_speed)
+			continue;
+
+		freq_table[i].index = i;
+		freq_table[i].frequency = prcm->mpu_speed / 1000;
+		i++;
+	}
+
 	freq_table[i].index = i;
 	freq_table[i].frequency = CPUFREQ_TABLE_END;
 
 	*table = &freq_table[0];
 }
+
+void omap2_clk_exit_cpufreq_table(struct cpufreq_frequency_table **table)
+{
+	kfree(freq_table);
+}
+
 #endif
 
 struct clk_functions omap2_clk_functions = {
@@ -497,6 +532,7 @@ struct clk_functions omap2_clk_functions = {
 	.clk_disable_unused	= omap2_clk_disable_unused,
 #ifdef	CONFIG_CPU_FREQ
 	.clk_init_cpufreq_table	= omap2_clk_init_cpufreq_table,
+	.clk_exit_cpufreq_table	= omap2_clk_exit_cpufreq_table,
 #endif
 };