xref: /openbmc/linux/drivers/clk/renesas/clk-emev2.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * EMMA Mobile EV2 common clock framework support
4  *
5  * Copyright (C) 2013 Takashi Yoshii <takashi.yoshii.ze@renesas.com>
6  * Copyright (C) 2012 Magnus Damm
7  */
8 #include <linux/clk-provider.h>
9 #include <linux/clkdev.h>
10 #include <linux/io.h>
11 #include <linux/of.h>
12 #include <linux/of_address.h>
13 
14 /* EMEV2 SMU registers */
15 #define USIAU0_RSTCTRL 0x094
16 #define USIBU1_RSTCTRL 0x0ac
17 #define USIBU2_RSTCTRL 0x0b0
18 #define USIBU3_RSTCTRL 0x0b4
19 #define IIC0_RSTCTRL 0x0dc
20 #define IIC1_RSTCTRL 0x0e0
21 #define STI_RSTCTRL 0x124
22 #define STI_CLKSEL 0x688
23 
24 static DEFINE_SPINLOCK(lock);
25 
26 /* not pretty, but hey */
27 static void __iomem *smu_base;
28 
29 static void __init emev2_smu_write(unsigned long value, int offs)
30 {
31 	BUG_ON(!smu_base || (offs >= PAGE_SIZE));
32 	writel_relaxed(value, smu_base + offs);
33 }
34 
35 static const struct of_device_id smu_id[] __initconst = {
36 	{ .compatible = "renesas,emev2-smu", },
37 	{},
38 };
39 
40 static void __init emev2_smu_init(void)
41 {
42 	struct device_node *np;
43 
44 	np = of_find_matching_node(NULL, smu_id);
45 	BUG_ON(!np);
46 	smu_base = of_iomap(np, 0);
47 	BUG_ON(!smu_base);
48 	of_node_put(np);
49 
50 	/* setup STI timer to run on 32.768 kHz and deassert reset */
51 	emev2_smu_write(0, STI_CLKSEL);
52 	emev2_smu_write(1, STI_RSTCTRL);
53 
54 	/* deassert reset for UART0->UART3 */
55 	emev2_smu_write(2, USIAU0_RSTCTRL);
56 	emev2_smu_write(2, USIBU1_RSTCTRL);
57 	emev2_smu_write(2, USIBU2_RSTCTRL);
58 	emev2_smu_write(2, USIBU3_RSTCTRL);
59 
60 	/* deassert reset for IIC0->IIC1 */
61 	emev2_smu_write(1, IIC0_RSTCTRL);
62 	emev2_smu_write(1, IIC1_RSTCTRL);
63 }
64 
65 static void __init emev2_smu_clkdiv_init(struct device_node *np)
66 {
67 	u32 reg[2];
68 	struct clk *clk;
69 	const char *parent_name = of_clk_get_parent_name(np, 0);
70 	if (WARN_ON(of_property_read_u32_array(np, "reg", reg, 2)))
71 		return;
72 	if (!smu_base)
73 		emev2_smu_init();
74 	clk = clk_register_divider(NULL, np->name, parent_name, 0,
75 				   smu_base + reg[0], reg[1], 8, 0, &lock);
76 	of_clk_add_provider(np, of_clk_src_simple_get, clk);
77 	clk_register_clkdev(clk, np->full_name, NULL);
78 	pr_debug("## %s %pOFn %p\n", __func__, np, clk);
79 }
80 CLK_OF_DECLARE(emev2_smu_clkdiv, "renesas,emev2-smu-clkdiv",
81 		emev2_smu_clkdiv_init);
82 
83 static void __init emev2_smu_gclk_init(struct device_node *np)
84 {
85 	u32 reg[2];
86 	struct clk *clk;
87 	const char *parent_name = of_clk_get_parent_name(np, 0);
88 	if (WARN_ON(of_property_read_u32_array(np, "reg", reg, 2)))
89 		return;
90 	if (!smu_base)
91 		emev2_smu_init();
92 	clk = clk_register_gate(NULL, np->name, parent_name, 0,
93 				smu_base + reg[0], reg[1], 0, &lock);
94 	of_clk_add_provider(np, of_clk_src_simple_get, clk);
95 	clk_register_clkdev(clk, np->full_name, NULL);
96 	pr_debug("## %s %pOFn %p\n", __func__, np, clk);
97 }
98 CLK_OF_DECLARE(emev2_smu_gclk, "renesas,emev2-smu-gclk", emev2_smu_gclk_init);
99