clk: socfpga: fix clock driver for 3.15

commit [1771b10 clk: respect the clock dependencies in of_clk_init]
exposed a flaw in the socfpga clock driver and prevents the platform
from booting on 3.15-rc1.

Because the "altr,clk-mgr" is not really a clock, it should not be using
CLK_OF_DECLARE, instead we should be mapping the clk-mgr's base address
one of the functional clock init function. Use the socfpga_pll_init function
to map the clk_mgr_base_addr as this clock should always be initialized first.

Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
Tested-by: Pavel Machek <pavel@denx.de>

drivers/clk/socfpga/clk-pll.c

@@ -20,6 +20,7 @@
 #include <linux/clk-provider.h>
 #include <linux/io.h>
 #include <linux/of.h>
+#include <linux/of_address.h>
 
 #include "clk.h"
 
@@ -43,6 +44,8 @@
 
 #define to_socfpga_clk(p) container_of(p, struct socfpga_pll, hw.hw)
 
+void __iomem *clk_mgr_base_addr;
+
 static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk,
 					 unsigned long parent_rate)
 {
@@ -87,6 +90,7 @@ static __init struct clk *__socfpga_pll_init(struct device_node *node,
 	const char *clk_name = node->name;
 	const char *parent_name[SOCFPGA_MAX_PARENTS];
 	struct clk_init_data init;
+	struct device_node *clkmgr_np;
 	int rc;
 	int i = 0;
 
@@ -96,6 +100,9 @@ static __init struct clk *__socfpga_pll_init(struct device_node *node,
 	if (WARN_ON(!pll_clk))
 		return NULL;
 
+	clkmgr_np = of_find_compatible_node(NULL, NULL, "altr,clk-mgr");
+	clk_mgr_base_addr = of_iomap(clkmgr_np, 0);
+	BUG_ON(!clk_mgr_base_addr);
 	pll_clk->hw.reg = clk_mgr_base_addr + reg;
 
 	of_property_read_string(node, "clock-output-names", &clk_name);

drivers/clk/socfpga/clk.c

@@ -17,28 +17,11 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#include <linux/clk.h>
-#include <linux/clkdev.h>
-#include <linux/clk-provider.h>
-#include <linux/io.h>
 #include <linux/of.h>
-#include <linux/of_address.h>
 
 #include "clk.h"
 
-void __iomem *clk_mgr_base_addr;
-
-static const struct of_device_id socfpga_child_clocks[] __initconst = {
-	{ .compatible = "altr,socfpga-pll-clock", socfpga_pll_init, },
-	{ .compatible = "altr,socfpga-perip-clk", socfpga_periph_init, },
-	{ .compatible = "altr,socfpga-gate-clk", socfpga_gate_init, },
-	{},
-};
-
-static void __init socfpga_clkmgr_init(struct device_node *node)
-{
-	clk_mgr_base_addr = of_iomap(node, 0);
-	of_clk_init(socfpga_child_clocks);
-}
-CLK_OF_DECLARE(socfpga_mgr, "altr,clk-mgr", socfpga_clkmgr_init);
+CLK_OF_DECLARE(socfpga_pll_clk, "altr,socfpga-pll-clock", socfpga_pll_init);
+CLK_OF_DECLARE(socfpga_perip_clk, "altr,socfpga-perip-clk", socfpga_periph_init);
+CLK_OF_DECLARE(socfpga_gate_clk, "altr,socfpga-gate-clk", socfpga_gate_init);