ARM: socfpga: Upgrade clk driver for socfpga to make use of dts clock entries

With this patch, the socfpga clk driver is able to query the clock and clock
rates appropriately.
Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
Reviewed-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Olof Johansson <olof@lixom.net>

arch/arm/mach-socfpga/socfpga.c

@@ -15,6 +15,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include <linux/dw_apb_timer.h>
+#include <linux/clk-provider.h>
 #include <linux/irqchip.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
@@ -29,6 +30,7 @@
 void __iomem *socfpga_scu_base_addr = ((void __iomem *)(SOCFPGA_SCU_VIRT_BASE));
 void __iomem *sys_manager_base_addr;
 void __iomem *rst_manager_base_addr;
+void __iomem *clk_mgr_base_addr;
 unsigned long cpu1start_addr;
 
 static struct map_desc scu_io_desc __initdata = {
@@ -77,6 +79,9 @@ void __init socfpga_sysmgr_init(void)
 
 	np = of_find_compatible_node(NULL, NULL, "altr,rst-mgr");
 	rst_manager_base_addr = of_iomap(np, 0);
+
+	np = of_find_compatible_node(NULL, NULL, "altr,clk-mgr");
+	clk_mgr_base_addr = of_iomap(np, 0);
 }
 
 static void __init socfpga_init_irq(void)
@@ -102,6 +107,7 @@ static void __init socfpga_cyclone5_init(void)
 {
 	l2x0_of_init(0, ~0UL);
 	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
+	of_clk_init(NULL);
 	socfpga_init_clocks();
 }
 

drivers/clk/socfpga/clk.c

 /*
- *  Copyright (C) 2012 Altera Corporation <www.altera.com>
+ *  Copyright 2011-2012 Calxeda, Inc.
+ *  Copyright (C) 2012-2013 Altera Corporation <www.altera.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -11,41 +12,161 @@
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
+ * Based from clk-highbank.c
+ *
  * 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>
 
-#define SOCFPGA_OSC1_CLK	10000000
-#define SOCFPGA_MPU_CLK		800000000
-#define SOCFPGA_MAIN_QSPI_CLK		432000000
-#define SOCFPGA_MAIN_NAND_SDMMC_CLK	250000000
-#define SOCFPGA_S2F_USR_CLK		125000000
+/* Clock Manager offsets */
+#define CLKMGR_CTRL    0x0
+#define CLKMGR_BYPASS 0x4
 
-void __init socfpga_init_clocks(void)
+/* Clock bypass bits */
+#define MAINPLL_BYPASS (1<<0)
+#define SDRAMPLL_BYPASS (1<<1)
+#define SDRAMPLL_SRC_BYPASS (1<<2)
+#define PERPLL_BYPASS (1<<3)
+#define PERPLL_SRC_BYPASS (1<<4)
+
+#define SOCFPGA_PLL_BG_PWRDWN		0
+#define SOCFPGA_PLL_EXT_ENA		1
+#define SOCFPGA_PLL_PWR_DOWN		2
+#define SOCFPGA_PLL_DIVF_MASK		0x0000FFF8
+#define SOCFPGA_PLL_DIVF_SHIFT	3
+#define SOCFPGA_PLL_DIVQ_MASK		0x003F0000
+#define SOCFPGA_PLL_DIVQ_SHIFT	16
+
+extern void __iomem *clk_mgr_base_addr;
+
+struct socfpga_clk {
+	struct clk_gate hw;
+	char *parent_name;
+	char *clk_name;
+	u32 fixed_div;
+};
+#define to_socfpga_clk(p) container_of(p, struct socfpga_clk, hw.hw)
+
+static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk,
+					 unsigned long parent_rate)
 {
+	struct socfpga_clk *socfpgaclk = to_socfpga_clk(hwclk);
+	unsigned long divf, divq, vco_freq, reg;
+	unsigned long bypass;
+
+	reg = readl(socfpgaclk->hw.reg);
+	bypass = readl(clk_mgr_base_addr + CLKMGR_BYPASS);
+	if (bypass & MAINPLL_BYPASS)
+		return parent_rate;
+
+	divf = (reg & SOCFPGA_PLL_DIVF_MASK) >> SOCFPGA_PLL_DIVF_SHIFT;
+	divq = (reg & SOCFPGA_PLL_DIVQ_MASK) >> SOCFPGA_PLL_DIVQ_SHIFT;
+	vco_freq = parent_rate * (divf + 1);
+	return vco_freq / (1 + divq);
+}
+
+
+static struct clk_ops clk_pll_ops = {
+	.recalc_rate = clk_pll_recalc_rate,
+};
+
+static unsigned long clk_periclk_recalc_rate(struct clk_hw *hwclk,
+					     unsigned long parent_rate)
+{
+	struct socfpga_clk *socfpgaclk = to_socfpga_clk(hwclk);
+	u32 div;
+
+	if (socfpgaclk->fixed_div)
+		div = socfpgaclk->fixed_div;
+	else
+		div = ((readl(socfpgaclk->hw.reg) & 0x1ff) + 1);
+
+	return parent_rate / div;
+}
+
+static const struct clk_ops periclk_ops = {
+	.recalc_rate = clk_periclk_recalc_rate,
+};
+
+static __init struct clk *socfpga_clk_init(struct device_node *node,
+	const struct clk_ops *ops)
+{
+	u32 reg;
 	struct clk *clk;
+	struct socfpga_clk *socfpga_clk;
+	const char *clk_name = node->name;
+	const char *parent_name;
+	struct clk_init_data init;
+	int rc;
+	u32 fixed_div;
+
+	rc = of_property_read_u32(node, "reg", &reg);
+	if (WARN_ON(rc))
+		return NULL;
+
+	socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
+	if (WARN_ON(!socfpga_clk))
+		return NULL;
+
+	socfpga_clk->hw.reg = clk_mgr_base_addr + reg;
+
+	rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
+	if (rc)
+		socfpga_clk->fixed_div = 0;
+	else
+		socfpga_clk->fixed_div = fixed_div;
+
+	of_property_read_string(node, "clock-output-names", &clk_name);
+
+	init.name = clk_name;
+	init.ops = ops;
+	init.flags = 0;
+	parent_name = of_clk_get_parent_name(node, 0);
+	init.parent_names = &parent_name;
+	init.num_parents = 1;
 
-	clk = clk_register_fixed_rate(NULL, "osc1_clk", NULL, CLK_IS_ROOT, SOCFPGA_OSC1_CLK);
-	clk_register_clkdev(clk, "osc1_clk", NULL);
+	socfpga_clk->hw.hw.init = &init;
 
-	clk = clk_register_fixed_rate(NULL, "mpu_clk", NULL, CLK_IS_ROOT, SOCFPGA_MPU_CLK);
-	clk_register_clkdev(clk, "mpu_clk", NULL);
+	if (strcmp(clk_name, "main_pll") || strcmp(clk_name, "periph_pll") ||
+			strcmp(clk_name, "sdram_pll")) {
+		socfpga_clk->hw.bit_idx = SOCFPGA_PLL_EXT_ENA;
+		clk_pll_ops.enable = clk_gate_ops.enable;
+		clk_pll_ops.disable = clk_gate_ops.disable;
+	}
 
-	clk = clk_register_fixed_rate(NULL, "main_clk", NULL, CLK_IS_ROOT, SOCFPGA_MPU_CLK/2);
-	clk_register_clkdev(clk, "main_clk", NULL);
+	clk = clk_register(NULL, &socfpga_clk->hw.hw);
+	if (WARN_ON(IS_ERR(clk))) {
+		kfree(socfpga_clk);
+		return NULL;
+	}
+	rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
+	return clk;
+}
 
-	clk = clk_register_fixed_rate(NULL, "dbg_base_clk", NULL, CLK_IS_ROOT, SOCFPGA_MPU_CLK/2);
-	clk_register_clkdev(clk, "dbg_base_clk", NULL);
+static void __init socfpga_pll_init(struct device_node *node)
+{
+	socfpga_clk_init(node, &clk_pll_ops);
+}
+CLK_OF_DECLARE(socfpga_pll, "altr,socfpga-pll-clock", socfpga_pll_init);
 
-	clk = clk_register_fixed_rate(NULL, "main_qspi_clk", NULL, CLK_IS_ROOT, SOCFPGA_MAIN_QSPI_CLK);
-	clk_register_clkdev(clk, "main_qspi_clk", NULL);
+static void __init socfpga_periph_init(struct device_node *node)
+{
+	socfpga_clk_init(node, &periclk_ops);
+}
+CLK_OF_DECLARE(socfpga_periph, "altr,socfpga-perip-clk", socfpga_periph_init);
 
-	clk = clk_register_fixed_rate(NULL, "main_nand_sdmmc_clk", NULL, CLK_IS_ROOT, SOCFPGA_MAIN_NAND_SDMMC_CLK);
-	clk_register_clkdev(clk, "main_nand_sdmmc_clk", NULL);
+void __init socfpga_init_clocks(void)
+{
+	struct clk *clk;
+	int ret;
 
-	clk = clk_register_fixed_rate(NULL, "s2f_usr_clk", NULL, CLK_IS_ROOT, SOCFPGA_S2F_USR_CLK);
-	clk_register_clkdev(clk, "s2f_usr_clk", NULL);
+	clk = clk_register_fixed_factor(NULL, "smp_twd", "mpuclk", 0, 1, 4);
+	ret = clk_register_clkdev(clk, NULL, "smp_twd");
+	if (ret)
+		pr_err("smp_twd alias not registered\n");
 }