xref: /openbmc/linux/drivers/clk/renesas/clk-emev2.c (revision 89feed8e)
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/io.h>
10 #include <linux/of.h>
11 #include <linux/of_address.h>
12 
13 /* EMEV2 SMU registers */
14 #define USIAU0_RSTCTRL 0x094
15 #define USIBU1_RSTCTRL 0x0ac
16 #define USIBU2_RSTCTRL 0x0b0
17 #define USIBU3_RSTCTRL 0x0b4
18 #define IIC0_RSTCTRL 0x0dc
19 #define IIC1_RSTCTRL 0x0e0
20 #define STI_RSTCTRL 0x124
21 #define STI_CLKSEL 0x688
22 
23 static DEFINE_SPINLOCK(lock);
24 
25 /* not pretty, but hey */
26 static void __iomem *smu_base;
27 
emev2_smu_write(unsigned long value,int offs)28 static void __init emev2_smu_write(unsigned long value, int offs)
29 {
30 	BUG_ON(!smu_base || (offs >= PAGE_SIZE));
31 	writel_relaxed(value, smu_base + offs);
32 }
33 
34 static const struct of_device_id smu_id[] __initconst = {
35 	{ .compatible = "renesas,emev2-smu", },
36 	{},
37 };
38 
emev2_smu_init(void)39 static void __init emev2_smu_init(void)
40 {
41 	struct device_node *np;
42 
43 	np = of_find_matching_node(NULL, smu_id);
44 	BUG_ON(!np);
45 	smu_base = of_iomap(np, 0);
46 	BUG_ON(!smu_base);
47 	of_node_put(np);
48 
49 	/* setup STI timer to run on 32.768 kHz and deassert reset */
50 	emev2_smu_write(0, STI_CLKSEL);
51 	emev2_smu_write(1, STI_RSTCTRL);
52 
53 	/* deassert reset for UART0->UART3 */
54 	emev2_smu_write(2, USIAU0_RSTCTRL);
55 	emev2_smu_write(2, USIBU1_RSTCTRL);
56 	emev2_smu_write(2, USIBU2_RSTCTRL);
57 	emev2_smu_write(2, USIBU3_RSTCTRL);
58 
59 	/* deassert reset for IIC0->IIC1 */
60 	emev2_smu_write(1, IIC0_RSTCTRL);
61 	emev2_smu_write(1, IIC1_RSTCTRL);
62 }
63 
emev2_smu_clkdiv_init(struct device_node * np)64 static void __init emev2_smu_clkdiv_init(struct device_node *np)
65 {
66 	u32 reg[2];
67 	struct clk *clk;
68 	const char *parent_name = of_clk_get_parent_name(np, 0);
69 	if (WARN_ON(of_property_read_u32_array(np, "reg", reg, 2)))
70 		return;
71 	if (!smu_base)
72 		emev2_smu_init();
73 	clk = clk_register_divider(NULL, np->name, parent_name, 0,
74 				   smu_base + reg[0], reg[1], 8, 0, &lock);
75 	of_clk_add_provider(np, of_clk_src_simple_get, clk);
76 	pr_debug("## %s %pOFn %p\n", __func__, np, clk);
77 }
78 CLK_OF_DECLARE(emev2_smu_clkdiv, "renesas,emev2-smu-clkdiv",
79 		emev2_smu_clkdiv_init);
80 
emev2_smu_gclk_init(struct device_node * np)81 static void __init emev2_smu_gclk_init(struct device_node *np)
82 {
83 	u32 reg[2];
84 	struct clk *clk;
85 	const char *parent_name = of_clk_get_parent_name(np, 0);
86 	if (WARN_ON(of_property_read_u32_array(np, "reg", reg, 2)))
87 		return;
88 	if (!smu_base)
89 		emev2_smu_init();
90 	clk = clk_register_gate(NULL, np->name, parent_name, 0,
91 				smu_base + reg[0], reg[1], 0, &lock);
92 	of_clk_add_provider(np, of_clk_src_simple_get, clk);
93 	pr_debug("## %s %pOFn %p\n", __func__, np, clk);
94 }
95 CLK_OF_DECLARE(emev2_smu_gclk, "renesas,emev2-smu-gclk", emev2_smu_gclk_init);
96