1 /*
2 * Copyright (c) 2013 Heiko Stuebner <heiko@sntech.de>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * Common Clock Framework support for S3C2412 and S3C2413.
9 */
10
11 #include <linux/clk-provider.h>
12 #include <linux/of.h>
13 #include <linux/of_address.h>
14 #include <linux/syscore_ops.h>
15 #include <linux/reboot.h>
16
17 #include <dt-bindings/clock/s3c2412.h>
18
19 #include "clk.h"
20 #include "clk-pll.h"
21
22 #define LOCKTIME 0x00
23 #define MPLLCON 0x04
24 #define UPLLCON 0x08
25 #define CLKCON 0x0c
26 #define CLKDIVN 0x14
27 #define CLKSRC 0x1c
28 #define SWRST 0x30
29
30 static void __iomem *reg_base;
31
32 #ifdef CONFIG_PM_SLEEP
33 static struct samsung_clk_reg_dump *s3c2412_save;
34
35 /*
36 * list of controller registers to be saved and restored during a
37 * suspend/resume cycle.
38 */
39 static unsigned long s3c2412_clk_regs[] __initdata = {
40 LOCKTIME,
41 MPLLCON,
42 UPLLCON,
43 CLKCON,
44 CLKDIVN,
45 CLKSRC,
46 };
47
s3c2412_clk_suspend(void)48 static int s3c2412_clk_suspend(void)
49 {
50 samsung_clk_save(reg_base, s3c2412_save,
51 ARRAY_SIZE(s3c2412_clk_regs));
52
53 return 0;
54 }
55
s3c2412_clk_resume(void)56 static void s3c2412_clk_resume(void)
57 {
58 samsung_clk_restore(reg_base, s3c2412_save,
59 ARRAY_SIZE(s3c2412_clk_regs));
60 }
61
62 static struct syscore_ops s3c2412_clk_syscore_ops = {
63 .suspend = s3c2412_clk_suspend,
64 .resume = s3c2412_clk_resume,
65 };
66
s3c2412_clk_sleep_init(void)67 static void __init s3c2412_clk_sleep_init(void)
68 {
69 s3c2412_save = samsung_clk_alloc_reg_dump(s3c2412_clk_regs,
70 ARRAY_SIZE(s3c2412_clk_regs));
71 if (!s3c2412_save) {
72 pr_warn("%s: failed to allocate sleep save data, no sleep support!\n",
73 __func__);
74 return;
75 }
76
77 register_syscore_ops(&s3c2412_clk_syscore_ops);
78 return;
79 }
80 #else
s3c2412_clk_sleep_init(void)81 static void __init s3c2412_clk_sleep_init(void) {}
82 #endif
83
84 static struct clk_div_table divxti_d[] = {
85 { .val = 0, .div = 1 },
86 { .val = 1, .div = 2 },
87 { .val = 2, .div = 4 },
88 { .val = 3, .div = 6 },
89 { .val = 4, .div = 8 },
90 { .val = 5, .div = 10 },
91 { .val = 6, .div = 12 },
92 { .val = 7, .div = 14 },
93 { /* sentinel */ },
94 };
95
96 static struct samsung_div_clock s3c2412_dividers[] __initdata = {
97 DIV_T(0, "div_xti", "xti", CLKSRC, 0, 3, divxti_d),
98 DIV(0, "div_cam", "mux_cam", CLKDIVN, 16, 4),
99 DIV(0, "div_i2s", "mux_i2s", CLKDIVN, 12, 4),
100 DIV(0, "div_uart", "mux_uart", CLKDIVN, 8, 4),
101 DIV(0, "div_usb", "mux_usb", CLKDIVN, 6, 1),
102 DIV(0, "div_hclk_half", "hclk", CLKDIVN, 5, 1),
103 DIV(ARMDIV, "armdiv", "msysclk", CLKDIVN, 3, 1),
104 DIV(PCLK, "pclk", "hclk", CLKDIVN, 2, 1),
105 DIV(HCLK, "hclk", "armdiv", CLKDIVN, 0, 2),
106 };
107
108 static struct samsung_fixed_factor_clock s3c2412_ffactor[] __initdata = {
109 FFACTOR(0, "ff_hclk", "hclk", 2, 1, CLK_SET_RATE_PARENT),
110 };
111
112 /*
113 * The first two use the OM[4] setting, which is not readable from
114 * software, so assume it is set to xti.
115 */
116 PNAME(erefclk_p) = { "xti", "xti", "xti", "ext" };
117 PNAME(urefclk_p) = { "xti", "xti", "xti", "ext" };
118
119 PNAME(camclk_p) = { "usysclk", "hclk" };
120 PNAME(usbclk_p) = { "usysclk", "hclk" };
121 PNAME(i2sclk_p) = { "erefclk", "mpll" };
122 PNAME(uartclk_p) = { "erefclk", "mpll" };
123 PNAME(usysclk_p) = { "urefclk", "upll" };
124 PNAME(msysclk_p) = { "mdivclk", "mpll" };
125 PNAME(mdivclk_p) = { "xti", "div_xti" };
126 PNAME(armclk_p) = { "armdiv", "hclk" };
127
128 static struct samsung_mux_clock s3c2412_muxes[] __initdata = {
129 MUX(0, "erefclk", erefclk_p, CLKSRC, 14, 2),
130 MUX(0, "urefclk", urefclk_p, CLKSRC, 12, 2),
131 MUX(0, "mux_cam", camclk_p, CLKSRC, 11, 1),
132 MUX(0, "mux_usb", usbclk_p, CLKSRC, 10, 1),
133 MUX(0, "mux_i2s", i2sclk_p, CLKSRC, 9, 1),
134 MUX(0, "mux_uart", uartclk_p, CLKSRC, 8, 1),
135 MUX(USYSCLK, "usysclk", usysclk_p, CLKSRC, 5, 1),
136 MUX(MSYSCLK, "msysclk", msysclk_p, CLKSRC, 4, 1),
137 MUX(MDIVCLK, "mdivclk", mdivclk_p, CLKSRC, 3, 1),
138 MUX(ARMCLK, "armclk", armclk_p, CLKDIVN, 4, 1),
139 };
140
141 static struct samsung_pll_clock s3c2412_plls[] __initdata = {
142 PLL(pll_s3c2440_mpll, MPLL, "mpll", "xti", LOCKTIME, MPLLCON, NULL),
143 PLL(pll_s3c2410_upll, UPLL, "upll", "urefclk", LOCKTIME, UPLLCON, NULL),
144 };
145
146 static struct samsung_gate_clock s3c2412_gates[] __initdata = {
147 GATE(PCLK_WDT, "wdt", "pclk", CLKCON, 28, 0, 0),
148 GATE(PCLK_SPI, "spi", "pclk", CLKCON, 27, 0, 0),
149 GATE(PCLK_I2S, "i2s", "pclk", CLKCON, 26, 0, 0),
150 GATE(PCLK_I2C, "i2c", "pclk", CLKCON, 25, 0, 0),
151 GATE(PCLK_ADC, "adc", "pclk", CLKCON, 24, 0, 0),
152 GATE(PCLK_RTC, "rtc", "pclk", CLKCON, 23, 0, 0),
153 GATE(PCLK_GPIO, "gpio", "pclk", CLKCON, 22, CLK_IGNORE_UNUSED, 0),
154 GATE(PCLK_UART2, "uart2", "pclk", CLKCON, 21, 0, 0),
155 GATE(PCLK_UART1, "uart1", "pclk", CLKCON, 20, 0, 0),
156 GATE(PCLK_UART0, "uart0", "pclk", CLKCON, 19, 0, 0),
157 GATE(PCLK_SDI, "sdi", "pclk", CLKCON, 18, 0, 0),
158 GATE(PCLK_PWM, "pwm", "pclk", CLKCON, 17, 0, 0),
159 GATE(PCLK_USBD, "usb-device", "pclk", CLKCON, 16, 0, 0),
160 GATE(SCLK_CAM, "sclk_cam", "div_cam", CLKCON, 15, 0, 0),
161 GATE(SCLK_UART, "sclk_uart", "div_uart", CLKCON, 14, 0, 0),
162 GATE(SCLK_I2S, "sclk_i2s", "div_i2s", CLKCON, 13, 0, 0),
163 GATE(SCLK_USBH, "sclk_usbh", "div_usb", CLKCON, 12, 0, 0),
164 GATE(SCLK_USBD, "sclk_usbd", "div_usb", CLKCON, 11, 0, 0),
165 GATE(HCLK_HALF, "hclk_half", "div_hclk_half", CLKCON, 10, CLK_IGNORE_UNUSED, 0),
166 GATE(HCLK_X2, "hclkx2", "ff_hclk", CLKCON, 9, CLK_IGNORE_UNUSED, 0),
167 GATE(HCLK_SDRAM, "sdram", "hclk", CLKCON, 8, CLK_IGNORE_UNUSED, 0),
168 GATE(HCLK_USBH, "usb-host", "hclk", CLKCON, 6, 0, 0),
169 GATE(HCLK_LCD, "lcd", "hclk", CLKCON, 5, 0, 0),
170 GATE(HCLK_NAND, "nand", "hclk", CLKCON, 4, 0, 0),
171 GATE(HCLK_DMA3, "dma3", "hclk", CLKCON, 3, CLK_IGNORE_UNUSED, 0),
172 GATE(HCLK_DMA2, "dma2", "hclk", CLKCON, 2, CLK_IGNORE_UNUSED, 0),
173 GATE(HCLK_DMA1, "dma1", "hclk", CLKCON, 1, CLK_IGNORE_UNUSED, 0),
174 GATE(HCLK_DMA0, "dma0", "hclk", CLKCON, 0, CLK_IGNORE_UNUSED, 0),
175 };
176
177 static struct samsung_clock_alias s3c2412_aliases[] __initdata = {
178 ALIAS(PCLK_UART0, "s3c2412-uart.0", "uart"),
179 ALIAS(PCLK_UART1, "s3c2412-uart.1", "uart"),
180 ALIAS(PCLK_UART2, "s3c2412-uart.2", "uart"),
181 ALIAS(PCLK_UART0, "s3c2412-uart.0", "clk_uart_baud2"),
182 ALIAS(PCLK_UART1, "s3c2412-uart.1", "clk_uart_baud2"),
183 ALIAS(PCLK_UART2, "s3c2412-uart.2", "clk_uart_baud2"),
184 ALIAS(SCLK_UART, NULL, "clk_uart_baud3"),
185 ALIAS(PCLK_I2C, "s3c2410-i2c.0", "i2c"),
186 ALIAS(PCLK_ADC, NULL, "adc"),
187 ALIAS(PCLK_RTC, NULL, "rtc"),
188 ALIAS(PCLK_PWM, NULL, "timers"),
189 ALIAS(HCLK_LCD, NULL, "lcd"),
190 ALIAS(PCLK_USBD, NULL, "usb-device"),
191 ALIAS(SCLK_USBD, NULL, "usb-bus-gadget"),
192 ALIAS(HCLK_USBH, NULL, "usb-host"),
193 ALIAS(SCLK_USBH, NULL, "usb-bus-host"),
194 ALIAS(ARMCLK, NULL, "armclk"),
195 ALIAS(HCLK, NULL, "hclk"),
196 ALIAS(MPLL, NULL, "mpll"),
197 ALIAS(MSYSCLK, NULL, "fclk"),
198 };
199
s3c2412_restart(struct notifier_block * this,unsigned long mode,void * cmd)200 static int s3c2412_restart(struct notifier_block *this,
201 unsigned long mode, void *cmd)
202 {
203 /* errata "Watch-dog/Software Reset Problem" specifies that
204 * this reset must be done with the SYSCLK sourced from
205 * EXTCLK instead of FOUT to avoid a glitch in the reset
206 * mechanism.
207 *
208 * See the watchdog section of the S3C2412 manual for more
209 * information on this fix.
210 */
211
212 __raw_writel(0x00, reg_base + CLKSRC);
213 __raw_writel(0x533C2412, reg_base + SWRST);
214 return NOTIFY_DONE;
215 }
216
217 static struct notifier_block s3c2412_restart_handler = {
218 .notifier_call = s3c2412_restart,
219 .priority = 129,
220 };
221
222 /*
223 * fixed rate clocks generated outside the soc
224 * Only necessary until the devicetree-move is complete
225 */
226 #define XTI 1
227 static struct samsung_fixed_rate_clock s3c2412_common_frate_clks[] __initdata = {
228 FRATE(XTI, "xti", NULL, 0, 0),
229 FRATE(0, "ext", NULL, 0, 0),
230 };
231
s3c2412_common_clk_register_fixed_ext(struct samsung_clk_provider * ctx,unsigned long xti_f,unsigned long ext_f)232 static void __init s3c2412_common_clk_register_fixed_ext(
233 struct samsung_clk_provider *ctx,
234 unsigned long xti_f, unsigned long ext_f)
235 {
236 /* xtal alias is necessary for the current cpufreq driver */
237 struct samsung_clock_alias xti_alias = ALIAS(XTI, NULL, "xtal");
238
239 s3c2412_common_frate_clks[0].fixed_rate = xti_f;
240 s3c2412_common_frate_clks[1].fixed_rate = ext_f;
241 samsung_clk_register_fixed_rate(ctx, s3c2412_common_frate_clks,
242 ARRAY_SIZE(s3c2412_common_frate_clks));
243
244 samsung_clk_register_alias(ctx, &xti_alias, 1);
245 }
246
s3c2412_common_clk_init(struct device_node * np,unsigned long xti_f,unsigned long ext_f,void __iomem * base)247 void __init s3c2412_common_clk_init(struct device_node *np, unsigned long xti_f,
248 unsigned long ext_f, void __iomem *base)
249 {
250 struct samsung_clk_provider *ctx;
251 int ret;
252 reg_base = base;
253
254 if (np) {
255 reg_base = of_iomap(np, 0);
256 if (!reg_base)
257 panic("%s: failed to map registers\n", __func__);
258 }
259
260 ctx = samsung_clk_init(np, reg_base, NR_CLKS);
261
262 /* Register external clocks only in non-dt cases */
263 if (!np)
264 s3c2412_common_clk_register_fixed_ext(ctx, xti_f, ext_f);
265
266 /* Register PLLs. */
267 samsung_clk_register_pll(ctx, s3c2412_plls, ARRAY_SIZE(s3c2412_plls),
268 reg_base);
269
270 /* Register common internal clocks. */
271 samsung_clk_register_mux(ctx, s3c2412_muxes, ARRAY_SIZE(s3c2412_muxes));
272 samsung_clk_register_div(ctx, s3c2412_dividers,
273 ARRAY_SIZE(s3c2412_dividers));
274 samsung_clk_register_gate(ctx, s3c2412_gates,
275 ARRAY_SIZE(s3c2412_gates));
276 samsung_clk_register_fixed_factor(ctx, s3c2412_ffactor,
277 ARRAY_SIZE(s3c2412_ffactor));
278 samsung_clk_register_alias(ctx, s3c2412_aliases,
279 ARRAY_SIZE(s3c2412_aliases));
280
281 s3c2412_clk_sleep_init();
282
283 samsung_clk_of_add_provider(np, ctx);
284
285 ret = register_restart_handler(&s3c2412_restart_handler);
286 if (ret)
287 pr_warn("cannot register restart handler, %d\n", ret);
288 }
289
s3c2412_clk_init(struct device_node * np)290 static void __init s3c2412_clk_init(struct device_node *np)
291 {
292 s3c2412_common_clk_init(np, 0, 0, NULL);
293 }
294 CLK_OF_DECLARE(s3c2412_clk, "samsung,s3c2412-clock", s3c2412_clk_init);
295
