xref: /openbmc/linux/drivers/clk/mxs/clk-imx23.c (revision 089a49b6)
1 /*
2  * Copyright 2012 Freescale Semiconductor, Inc.
3  *
4  * The code contained herein is licensed under the GNU General Public
5  * License. You may obtain a copy of the GNU General Public License
6  * Version 2 or later at the following locations:
7  *
8  * http://www.opensource.org/licenses/gpl-license.html
9  * http://www.gnu.org/copyleft/gpl.html
10  */
11 
12 #include <linux/clk.h>
13 #include <linux/clk/mxs.h>
14 #include <linux/clkdev.h>
15 #include <linux/err.h>
16 #include <linux/init.h>
17 #include <linux/io.h>
18 #include <linux/of.h>
19 #include <linux/of_address.h>
20 #include "clk.h"
21 
22 static void __iomem *clkctrl;
23 static void __iomem *digctrl;
24 
25 #define CLKCTRL clkctrl
26 #define DIGCTRL digctrl
27 
28 #define PLLCTRL0		(CLKCTRL + 0x0000)
29 #define CPU			(CLKCTRL + 0x0020)
30 #define HBUS			(CLKCTRL + 0x0030)
31 #define XBUS			(CLKCTRL + 0x0040)
32 #define XTAL			(CLKCTRL + 0x0050)
33 #define PIX			(CLKCTRL + 0x0060)
34 #define SSP			(CLKCTRL + 0x0070)
35 #define GPMI			(CLKCTRL + 0x0080)
36 #define SPDIF			(CLKCTRL + 0x0090)
37 #define EMI			(CLKCTRL + 0x00a0)
38 #define SAIF			(CLKCTRL + 0x00c0)
39 #define TV			(CLKCTRL + 0x00d0)
40 #define ETM			(CLKCTRL + 0x00e0)
41 #define FRAC			(CLKCTRL + 0x00f0)
42 #define CLKSEQ			(CLKCTRL + 0x0110)
43 
44 #define BP_CPU_INTERRUPT_WAIT	12
45 #define BP_CLKSEQ_BYPASS_SAIF	0
46 #define BP_CLKSEQ_BYPASS_SSP	5
47 #define BP_SAIF_DIV_FRAC_EN	16
48 #define BP_FRAC_IOFRAC		24
49 
50 static void __init clk_misc_init(void)
51 {
52 	u32 val;
53 
54 	/* Gate off cpu clock in WFI for power saving */
55 	writel_relaxed(1 << BP_CPU_INTERRUPT_WAIT, CPU + SET);
56 
57 	/* Clear BYPASS for SAIF */
58 	writel_relaxed(1 << BP_CLKSEQ_BYPASS_SAIF, CLKSEQ + CLR);
59 
60 	/* SAIF has to use frac div for functional operation */
61 	val = readl_relaxed(SAIF);
62 	val |= 1 << BP_SAIF_DIV_FRAC_EN;
63 	writel_relaxed(val, SAIF);
64 
65 	/*
66 	 * Source ssp clock from ref_io than ref_xtal,
67 	 * as ref_xtal only provides 24 MHz as maximum.
68 	 */
69 	writel_relaxed(1 << BP_CLKSEQ_BYPASS_SSP, CLKSEQ + CLR);
70 
71 	/*
72 	 * 480 MHz seems too high to be ssp clock source directly,
73 	 * so set frac to get a 288 MHz ref_io.
74 	 */
75 	writel_relaxed(0x3f << BP_FRAC_IOFRAC, FRAC + CLR);
76 	writel_relaxed(30 << BP_FRAC_IOFRAC, FRAC + SET);
77 }
78 
79 static const char *sel_pll[]  __initconst = { "pll", "ref_xtal", };
80 static const char *sel_cpu[]  __initconst = { "ref_cpu", "ref_xtal", };
81 static const char *sel_pix[]  __initconst = { "ref_pix", "ref_xtal", };
82 static const char *sel_io[]   __initconst = { "ref_io", "ref_xtal", };
83 static const char *cpu_sels[] __initconst = { "cpu_pll", "cpu_xtal", };
84 static const char *emi_sels[] __initconst = { "emi_pll", "emi_xtal", };
85 
86 enum imx23_clk {
87 	ref_xtal, pll, ref_cpu, ref_emi, ref_pix, ref_io, saif_sel,
88 	lcdif_sel, gpmi_sel, ssp_sel, emi_sel, cpu, etm_sel, cpu_pll,
89 	cpu_xtal, hbus, xbus, lcdif_div, ssp_div, gpmi_div, emi_pll,
90 	emi_xtal, etm_div, saif_div, clk32k_div, rtc, adc, spdif_div,
91 	clk32k, dri, pwm, filt, uart, ssp, gpmi, spdif, emi, saif,
92 	lcdif, etm, usb, usb_phy,
93 	clk_max
94 };
95 
96 static struct clk *clks[clk_max];
97 static struct clk_onecell_data clk_data;
98 
99 static enum imx23_clk clks_init_on[] __initdata = {
100 	cpu, hbus, xbus, emi, uart,
101 };
102 
103 int __init mx23_clocks_init(void)
104 {
105 	struct device_node *np;
106 	u32 i;
107 
108 	np = of_find_compatible_node(NULL, NULL, "fsl,imx23-digctl");
109 	digctrl = of_iomap(np, 0);
110 	WARN_ON(!digctrl);
111 
112 	np = of_find_compatible_node(NULL, NULL, "fsl,imx23-clkctrl");
113 	clkctrl = of_iomap(np, 0);
114 	WARN_ON(!clkctrl);
115 
116 	clk_misc_init();
117 
118 	clks[ref_xtal] = mxs_clk_fixed("ref_xtal", 24000000);
119 	clks[pll] = mxs_clk_pll("pll", "ref_xtal", PLLCTRL0, 16, 480000000);
120 	clks[ref_cpu] = mxs_clk_ref("ref_cpu", "pll", FRAC, 0);
121 	clks[ref_emi] = mxs_clk_ref("ref_emi", "pll", FRAC, 1);
122 	clks[ref_pix] = mxs_clk_ref("ref_pix", "pll", FRAC, 2);
123 	clks[ref_io] = mxs_clk_ref("ref_io", "pll", FRAC, 3);
124 	clks[saif_sel] = mxs_clk_mux("saif_sel", CLKSEQ, 0, 1, sel_pll, ARRAY_SIZE(sel_pll));
125 	clks[lcdif_sel] = mxs_clk_mux("lcdif_sel", CLKSEQ, 1, 1, sel_pix, ARRAY_SIZE(sel_pix));
126 	clks[gpmi_sel] = mxs_clk_mux("gpmi_sel", CLKSEQ, 4, 1, sel_io, ARRAY_SIZE(sel_io));
127 	clks[ssp_sel] = mxs_clk_mux("ssp_sel", CLKSEQ, 5, 1, sel_io, ARRAY_SIZE(sel_io));
128 	clks[emi_sel] = mxs_clk_mux("emi_sel", CLKSEQ, 6, 1, emi_sels, ARRAY_SIZE(emi_sels));
129 	clks[cpu] = mxs_clk_mux("cpu", CLKSEQ, 7, 1, cpu_sels, ARRAY_SIZE(cpu_sels));
130 	clks[etm_sel] = mxs_clk_mux("etm_sel", CLKSEQ, 8, 1, sel_cpu, ARRAY_SIZE(sel_cpu));
131 	clks[cpu_pll] = mxs_clk_div("cpu_pll", "ref_cpu", CPU, 0, 6, 28);
132 	clks[cpu_xtal] = mxs_clk_div("cpu_xtal", "ref_xtal", CPU, 16, 10, 29);
133 	clks[hbus] = mxs_clk_div("hbus", "cpu", HBUS, 0, 5, 29);
134 	clks[xbus] = mxs_clk_div("xbus", "ref_xtal", XBUS, 0, 10, 31);
135 	clks[lcdif_div] = mxs_clk_div("lcdif_div", "lcdif_sel", PIX, 0, 12, 29);
136 	clks[ssp_div] = mxs_clk_div("ssp_div", "ssp_sel", SSP, 0, 9, 29);
137 	clks[gpmi_div] = mxs_clk_div("gpmi_div", "gpmi_sel", GPMI, 0, 10, 29);
138 	clks[emi_pll] = mxs_clk_div("emi_pll", "ref_emi", EMI, 0, 6, 28);
139 	clks[emi_xtal] = mxs_clk_div("emi_xtal", "ref_xtal", EMI, 8, 4, 29);
140 	clks[etm_div] = mxs_clk_div("etm_div", "etm_sel", ETM, 0, 6, 29);
141 	clks[saif_div] = mxs_clk_frac("saif_div", "saif_sel", SAIF, 0, 16, 29);
142 	clks[clk32k_div] = mxs_clk_fixed_factor("clk32k_div", "ref_xtal", 1, 750);
143 	clks[rtc] = mxs_clk_fixed_factor("rtc", "ref_xtal", 1, 768);
144 	clks[adc] = mxs_clk_fixed_factor("adc", "clk32k", 1, 16);
145 	clks[spdif_div] = mxs_clk_fixed_factor("spdif_div", "pll", 1, 4);
146 	clks[clk32k] = mxs_clk_gate("clk32k", "clk32k_div", XTAL, 26);
147 	clks[dri] = mxs_clk_gate("dri", "ref_xtal", XTAL, 28);
148 	clks[pwm] = mxs_clk_gate("pwm", "ref_xtal", XTAL, 29);
149 	clks[filt] = mxs_clk_gate("filt", "ref_xtal", XTAL, 30);
150 	clks[uart] = mxs_clk_gate("uart", "ref_xtal", XTAL, 31);
151 	clks[ssp] = mxs_clk_gate("ssp", "ssp_div", SSP, 31);
152 	clks[gpmi] = mxs_clk_gate("gpmi", "gpmi_div", GPMI, 31);
153 	clks[spdif] = mxs_clk_gate("spdif", "spdif_div", SPDIF, 31);
154 	clks[emi] = mxs_clk_gate("emi", "emi_sel", EMI, 31);
155 	clks[saif] = mxs_clk_gate("saif", "saif_div", SAIF, 31);
156 	clks[lcdif] = mxs_clk_gate("lcdif", "lcdif_div", PIX, 31);
157 	clks[etm] = mxs_clk_gate("etm", "etm_div", ETM, 31);
158 	clks[usb] = mxs_clk_gate("usb", "usb_phy", DIGCTRL, 2);
159 	clks[usb_phy] = clk_register_gate(NULL, "usb_phy", "pll", 0, PLLCTRL0, 18, 0, &mxs_lock);
160 
161 	for (i = 0; i < ARRAY_SIZE(clks); i++)
162 		if (IS_ERR(clks[i])) {
163 			pr_err("i.MX23 clk %d: register failed with %ld\n",
164 				i, PTR_ERR(clks[i]));
165 			return PTR_ERR(clks[i]);
166 		}
167 
168 	clk_data.clks = clks;
169 	clk_data.clk_num = ARRAY_SIZE(clks);
170 	of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
171 
172 	for (i = 0; i < ARRAY_SIZE(clks_init_on); i++)
173 		clk_prepare_enable(clks[clks_init_on[i]]);
174 
175 	return 0;
176 }
177