1 /*
2  * Copyright (c) 2011 The Chromium OS Authors.
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 /* Tegra clock control functions */
8 
9 #ifndef _TEGRA_CLOCK_H_
10 #define _TEGRA_CLOCK_H_
11 
12 /* Set of oscillator frequencies supported in the internal API. */
13 enum clock_osc_freq {
14 	/* All in MHz, so 13_0 is 13.0MHz */
15 	CLOCK_OSC_FREQ_13_0,
16 	CLOCK_OSC_FREQ_19_2,
17 	CLOCK_OSC_FREQ_12_0,
18 	CLOCK_OSC_FREQ_26_0,
19 
20 	CLOCK_OSC_FREQ_COUNT,
21 };
22 
23 #include <asm/arch/clock-tables.h>
24 /* PLL stabilization delay in usec */
25 #define CLOCK_PLL_STABLE_DELAY_US 300
26 
27 /* return the current oscillator clock frequency */
28 enum clock_osc_freq clock_get_osc_freq(void);
29 
30 /**
31  * Start PLL using the provided configuration parameters.
32  *
33  * @param id	clock id
34  * @param divm	input divider
35  * @param divn	feedback divider
36  * @param divp	post divider 2^n
37  * @param cpcon	charge pump setup control
38  * @param lfcon	loop filter setup control
39  *
40  * @returns monotonic time in us that the PLL will be stable
41  */
42 unsigned long clock_start_pll(enum clock_id id, u32 divm, u32 divn,
43 		u32 divp, u32 cpcon, u32 lfcon);
44 
45 /**
46  * Set PLL output frequency
47  *
48  * @param clkid	clock id
49  * @param pllout	pll output id
50  * @param rate		desired output rate
51  *
52  * @return 0 if ok, -1 on error (invalid clock id or no suitable divider)
53  */
54 int clock_set_pllout(enum clock_id clkid, enum pll_out_id pllout,
55 		unsigned rate);
56 
57 /**
58  * Read low-level parameters of a PLL.
59  *
60  * @param id	clock id to read (note: USB is not supported)
61  * @param divm	returns input divider
62  * @param divn	returns feedback divider
63  * @param divp	returns post divider 2^n
64  * @param cpcon	returns charge pump setup control
65  * @param lfcon	returns loop filter setup control
66  *
67  * @returns 0 if ok, -1 on error (invalid clock id)
68  */
69 int clock_ll_read_pll(enum clock_id clkid, u32 *divm, u32 *divn,
70 		u32 *divp, u32 *cpcon, u32 *lfcon);
71 
72 /*
73  * Enable a clock
74  *
75  * @param id	clock id
76  */
77 void clock_enable(enum periph_id clkid);
78 
79 /*
80  * Disable a clock
81  *
82  * @param id	clock id
83  */
84 void clock_disable(enum periph_id clkid);
85 
86 /*
87  * Set whether a clock is enabled or disabled.
88  *
89  * @param id		clock id
90  * @param enable	1 to enable, 0 to disable
91  */
92 void clock_set_enable(enum periph_id clkid, int enable);
93 
94 /**
95  * Reset a peripheral. This puts it in reset, waits for a delay, then takes
96  * it out of reset and waits for th delay again.
97  *
98  * @param periph_id	peripheral to reset
99  * @param us_delay	time to delay in microseconds
100  */
101 void reset_periph(enum periph_id periph_id, int us_delay);
102 
103 /**
104  * Put a peripheral into or out of reset.
105  *
106  * @param periph_id	peripheral to reset
107  * @param enable	1 to put into reset, 0 to take out of reset
108  */
109 void reset_set_enable(enum periph_id periph_id, int enable);
110 
111 
112 /* CLK_RST_CONTROLLER_RST_CPU_CMPLX_SET/CLR_0 */
113 enum crc_reset_id {
114 	/* Things we can hold in reset for each CPU */
115 	crc_rst_cpu = 1,
116 	crc_rst_de = 1 << 2,	/* What is de? */
117 	crc_rst_watchdog = 1 << 3,
118 	crc_rst_debug = 1 << 4,
119 };
120 
121 /**
122  * Put parts of the CPU complex into or out of reset.\
123  *
124  * @param cpu		cpu number (0 or 1 on Tegra2, 0-3 on Tegra3)
125  * @param which		which parts of the complex to affect (OR of crc_reset_id)
126  * @param reset		1 to assert reset, 0 to de-assert
127  */
128 void reset_cmplx_set_enable(int cpu, int which, int reset);
129 
130 /**
131  * Set the source for a peripheral clock. This plus the divisor sets the
132  * clock rate. You need to look up the datasheet to see the meaning of the
133  * source parameter as it changes for each peripheral.
134  *
135  * Warning: This function is only for use pre-relocation. Please use
136  * clock_start_periph_pll() instead.
137  *
138  * @param periph_id	peripheral to adjust
139  * @param source	source clock (0, 1, 2 or 3)
140  */
141 void clock_ll_set_source(enum periph_id periph_id, unsigned source);
142 
143 /**
144  * Set the source and divisor for a peripheral clock. This sets the
145  * clock rate. You need to look up the datasheet to see the meaning of the
146  * source parameter as it changes for each peripheral.
147  *
148  * Warning: This function is only for use pre-relocation. Please use
149  * clock_start_periph_pll() instead.
150  *
151  * @param periph_id	peripheral to adjust
152  * @param source	source clock (0, 1, 2 or 3)
153  * @param divisor	divisor value to use
154  */
155 void clock_ll_set_source_divisor(enum periph_id periph_id, unsigned source,
156 		unsigned divisor);
157 
158 /**
159  * Start a peripheral PLL clock at the given rate. This also resets the
160  * peripheral.
161  *
162  * @param periph_id	peripheral to start
163  * @param parent	PLL id of required parent clock
164  * @param rate		Required clock rate in Hz
165  * @return rate selected in Hz, or -1U if something went wrong
166  */
167 unsigned clock_start_periph_pll(enum periph_id periph_id,
168 		enum clock_id parent, unsigned rate);
169 
170 /**
171  * Returns the rate of a peripheral clock in Hz. Since the caller almost
172  * certainly knows the parent clock (having just set it) we require that
173  * this be passed in so we don't need to work it out.
174  *
175  * @param periph_id	peripheral to start
176  * @param parent	PLL id of parent clock (used to calculate rate, you
177  *			must know this!)
178  * @return clock rate of peripheral in Hz
179  */
180 unsigned long clock_get_periph_rate(enum periph_id periph_id,
181 		enum clock_id parent);
182 
183 /**
184  * Adjust peripheral PLL clock to the given rate. This does not reset the
185  * peripheral. If a second stage divisor is not available, pass NULL for
186  * extra_div. If it is available, then this parameter will return the
187  * divisor selected (which will be a power of 2 from 1 to 256).
188  *
189  * @param periph_id	peripheral to start
190  * @param parent	PLL id of required parent clock
191  * @param rate		Required clock rate in Hz
192  * @param extra_div	value for the second-stage divisor (NULL if one is
193 			not available)
194  * @return rate selected in Hz, or -1U if something went wrong
195  */
196 unsigned clock_adjust_periph_pll_div(enum periph_id periph_id,
197 		enum clock_id parent, unsigned rate, int *extra_div);
198 
199 /**
200  * Returns the clock rate of a specified clock, in Hz.
201  *
202  * @param parent	PLL id of clock to check
203  * @return rate of clock in Hz
204  */
205 unsigned clock_get_rate(enum clock_id clkid);
206 
207 /**
208  * Start up a UART using low-level calls
209  *
210  * Prior to relocation clock_start_periph_pll() cannot be called. This
211  * function provides a way to set up a UART using low-level calls which
212  * do not require BSS.
213  *
214  * @param periph_id	Peripheral ID of UART to enable (e,g, PERIPH_ID_UART1)
215  */
216 void clock_ll_start_uart(enum periph_id periph_id);
217 
218 /**
219  * Decode a peripheral ID from a device tree node.
220  *
221  * This works by looking up the peripheral's 'clocks' node and reading out
222  * the second cell, which is the clock number / peripheral ID.
223  *
224  * @param blob		FDT blob to use
225  * @param node		Node to look at
226  * @return peripheral ID, or PERIPH_ID_NONE if none
227  */
228 enum periph_id clock_decode_periph_id(const void *blob, int node);
229 
230 /**
231  * Checks if the oscillator bypass is enabled (XOBP bit)
232  *
233  * @return 1 if bypass is enabled, 0 if not
234  */
235 int clock_get_osc_bypass(void);
236 
237 /*
238  * Checks that clocks are valid and prints a warning if not
239  *
240  * @return 0 if ok, -1 on error
241  */
242 int clock_verify(void);
243 
244 /* Initialize the clocks */
245 void clock_init(void);
246 
247 /* Initialize the PLLs */
248 void clock_early_init(void);
249 
250 /* Returns a pointer to the clock source register for a peripheral */
251 u32 *get_periph_source_reg(enum periph_id periph_id);
252 
253 /**
254  * Given a peripheral ID and the required source clock, this returns which
255  * value should be programmed into the source mux for that peripheral.
256  *
257  * There is special code here to handle the one source type with 5 sources.
258  *
259  * @param periph_id     peripheral to start
260  * @param source        PLL id of required parent clock
261  * @param mux_bits      Set to number of bits in mux register: 2 or 4
262  * @param divider_bits  Set to number of divider bits (8 or 16)
263  * @return mux value (0-4, or -1 if not found)
264  */
265 int get_periph_clock_source(enum periph_id periph_id,
266 		enum clock_id parent, int *mux_bits, int *divider_bits);
267 
268 /*
269  * Convert a device tree clock ID to our peripheral ID. They are mostly
270  * the same but we are very cautious so we check that a valid clock ID is
271  * provided.
272  *
273  * @param clk_id        Clock ID according to tegra30 device tree binding
274  * @return peripheral ID, or PERIPH_ID_NONE if the clock ID is invalid
275  */
276 enum periph_id clk_id_to_periph_id(int clk_id);
277 
278 /**
279  * Set the output frequency you want for each PLL clock.
280  * PLL output frequencies are programmed by setting their N, M and P values.
281  * The governing equations are:
282  *     VCO = (Fi / m) * n, Fo = VCO / (2^p)
283  *     where Fo is the output frequency from the PLL.
284  * Example: Set the output frequency to 216Mhz(Fo) with 12Mhz OSC(Fi)
285  *     216Mhz = ((12Mhz / m) * n) / (2^p) so n=432,m=12,p=1
286  * Please see Tegra TRM section 5.3 to get the detail for PLL Programming
287  *
288  * @param n PLL feedback divider(DIVN)
289  * @param m PLL input divider(DIVN)
290  * @param p post divider(DIVP)
291  * @param cpcon base PLL charge pump(CPCON)
292  * @return 0 if ok, -1 on error (the requested PLL is incorrect and cannot
293  *              be overriden), 1 if PLL is already correct
294  */
295 int clock_set_rate(enum clock_id clkid, u32 n, u32 m, u32 p, u32 cpcon);
296 
297 /* return 1 if a peripheral ID is in range */
298 #define clock_type_id_isvalid(id) ((id) >= 0 && \
299 		(id) < CLOCK_TYPE_COUNT)
300 
301 /* return 1 if a periphc_internal_id is in range */
302 #define periphc_internal_id_isvalid(id) ((id) >= 0 && \
303 		(id) < PERIPHC_COUNT)
304 
305 /* SoC-specific TSC init */
306 void arch_timer_init(void);
307 
308 #endif  /* _TEGRA_CLOCK_H_ */
309