xref: /linux/drivers/clk/renesas/clk-emev2.c (revision b6ebbac51bedf9e98e837688bc838f400196da5e)
1 /*
2  * EMMA Mobile EV2 common clock framework support
3  *
4  * Copyright (C) 2013 Takashi Yoshii <takashi.yoshii.ze@renesas.com>
5  * Copyright (C) 2012 Magnus Damm
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; version 2 of the License.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
19  */
20 #include <linux/clk-provider.h>
21 #include <linux/clkdev.h>
22 #include <linux/io.h>
23 #include <linux/of.h>
24 #include <linux/of_address.h>
25 
26 /* EMEV2 SMU registers */
27 #define USIAU0_RSTCTRL 0x094
28 #define USIBU1_RSTCTRL 0x0ac
29 #define USIBU2_RSTCTRL 0x0b0
30 #define USIBU3_RSTCTRL 0x0b4
31 #define IIC0_RSTCTRL 0x0dc
32 #define IIC1_RSTCTRL 0x0e0
33 #define STI_RSTCTRL 0x124
34 #define STI_CLKSEL 0x688
35 
36 static DEFINE_SPINLOCK(lock);
37 
38 /* not pretty, but hey */
39 static void __iomem *smu_base;
40 
41 static void __init emev2_smu_write(unsigned long value, int offs)
42 {
43 	BUG_ON(!smu_base || (offs >= PAGE_SIZE));
44 	writel_relaxed(value, smu_base + offs);
45 }
46 
47 static const struct of_device_id smu_id[] __initconst = {
48 	{ .compatible = "renesas,emev2-smu", },
49 	{},
50 };
51 
52 static void __init emev2_smu_init(void)
53 {
54 	struct device_node *np;
55 
56 	np = of_find_matching_node(NULL, smu_id);
57 	BUG_ON(!np);
58 	smu_base = of_iomap(np, 0);
59 	BUG_ON(!smu_base);
60 	of_node_put(np);
61 
62 	/* setup STI timer to run on 32.768 kHz and deassert reset */
63 	emev2_smu_write(0, STI_CLKSEL);
64 	emev2_smu_write(1, STI_RSTCTRL);
65 
66 	/* deassert reset for UART0->UART3 */
67 	emev2_smu_write(2, USIAU0_RSTCTRL);
68 	emev2_smu_write(2, USIBU1_RSTCTRL);
69 	emev2_smu_write(2, USIBU2_RSTCTRL);
70 	emev2_smu_write(2, USIBU3_RSTCTRL);
71 
72 	/* deassert reset for IIC0->IIC1 */
73 	emev2_smu_write(1, IIC0_RSTCTRL);
74 	emev2_smu_write(1, IIC1_RSTCTRL);
75 }
76 
77 static void __init emev2_smu_clkdiv_init(struct device_node *np)
78 {
79 	u32 reg[2];
80 	struct clk *clk;
81 	const char *parent_name = of_clk_get_parent_name(np, 0);
82 	if (WARN_ON(of_property_read_u32_array(np, "reg", reg, 2)))
83 		return;
84 	if (!smu_base)
85 		emev2_smu_init();
86 	clk = clk_register_divider(NULL, np->name, parent_name, 0,
87 				   smu_base + reg[0], reg[1], 8, 0, &lock);
88 	of_clk_add_provider(np, of_clk_src_simple_get, clk);
89 	clk_register_clkdev(clk, np->name, NULL);
90 	pr_debug("## %s %s %p\n", __func__, np->name, clk);
91 }
92 CLK_OF_DECLARE(emev2_smu_clkdiv, "renesas,emev2-smu-clkdiv",
93 		emev2_smu_clkdiv_init);
94 
95 static void __init emev2_smu_gclk_init(struct device_node *np)
96 {
97 	u32 reg[2];
98 	struct clk *clk;
99 	const char *parent_name = of_clk_get_parent_name(np, 0);
100 	if (WARN_ON(of_property_read_u32_array(np, "reg", reg, 2)))
101 		return;
102 	if (!smu_base)
103 		emev2_smu_init();
104 	clk = clk_register_gate(NULL, np->name, parent_name, 0,
105 				smu_base + reg[0], reg[1], 0, &lock);
106 	of_clk_add_provider(np, of_clk_src_simple_get, clk);
107 	clk_register_clkdev(clk, np->name, NULL);
108 	pr_debug("## %s %s %p\n", __func__, np->name, clk);
109 }
110 CLK_OF_DECLARE(emev2_smu_gclk, "renesas,emev2-smu-gclk", emev2_smu_gclk_init);
111