1 /*
2  * Copyright (c) 2011 The Chromium OS Authors.
3  * See file CREDITS for list of people who contributed to this
4  * project.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as
8  * published by the Free Software Foundation; either version 2 of
9  * the License, or (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
19  * MA 02111-1307 USA
20  */
21 
22 /* Tegra clock control functions */
23 
24 #ifndef _TEGRA_CLOCK_H_
25 #define _TEGRA_CLOCK_H_
26 
27 /* Set of oscillator frequencies supported in the internal API. */
28 enum clock_osc_freq {
29 	/* All in MHz, so 13_0 is 13.0MHz */
30 	CLOCK_OSC_FREQ_13_0,
31 	CLOCK_OSC_FREQ_19_2,
32 	CLOCK_OSC_FREQ_12_0,
33 	CLOCK_OSC_FREQ_26_0,
34 
35 	CLOCK_OSC_FREQ_COUNT,
36 };
37 
38 #include <asm/arch/clock-tables.h>
39 /* PLL stabilization delay in usec */
40 #define CLOCK_PLL_STABLE_DELAY_US 300
41 
42 /* return the current oscillator clock frequency */
43 enum clock_osc_freq clock_get_osc_freq(void);
44 
45 /**
46  * Start PLL using the provided configuration parameters.
47  *
48  * @param id	clock id
49  * @param divm	input divider
50  * @param divn	feedback divider
51  * @param divp	post divider 2^n
52  * @param cpcon	charge pump setup control
53  * @param lfcon	loop filter setup control
54  *
55  * @returns monotonic time in us that the PLL will be stable
56  */
57 unsigned long clock_start_pll(enum clock_id id, u32 divm, u32 divn,
58 		u32 divp, u32 cpcon, u32 lfcon);
59 
60 /**
61  * Set PLL output frequency
62  *
63  * @param clkid	clock id
64  * @param pllout	pll output id
65  * @param rate		desired output rate
66  *
67  * @return 0 if ok, -1 on error (invalid clock id or no suitable divider)
68  */
69 int clock_set_pllout(enum clock_id clkid, enum pll_out_id pllout,
70 		unsigned rate);
71 
72 /**
73  * Read low-level parameters of a PLL.
74  *
75  * @param id	clock id to read (note: USB is not supported)
76  * @param divm	returns input divider
77  * @param divn	returns feedback divider
78  * @param divp	returns post divider 2^n
79  * @param cpcon	returns charge pump setup control
80  * @param lfcon	returns loop filter setup control
81  *
82  * @returns 0 if ok, -1 on error (invalid clock id)
83  */
84 int clock_ll_read_pll(enum clock_id clkid, u32 *divm, u32 *divn,
85 		u32 *divp, u32 *cpcon, u32 *lfcon);
86 
87 /*
88  * Enable a clock
89  *
90  * @param id	clock id
91  */
92 void clock_enable(enum periph_id clkid);
93 
94 /*
95  * Disable a clock
96  *
97  * @param id	clock id
98  */
99 void clock_disable(enum periph_id clkid);
100 
101 /*
102  * Set whether a clock is enabled or disabled.
103  *
104  * @param id		clock id
105  * @param enable	1 to enable, 0 to disable
106  */
107 void clock_set_enable(enum periph_id clkid, int enable);
108 
109 /**
110  * Reset a peripheral. This puts it in reset, waits for a delay, then takes
111  * it out of reset and waits for th delay again.
112  *
113  * @param periph_id	peripheral to reset
114  * @param us_delay	time to delay in microseconds
115  */
116 void reset_periph(enum periph_id periph_id, int us_delay);
117 
118 /**
119  * Put a peripheral into or out of reset.
120  *
121  * @param periph_id	peripheral to reset
122  * @param enable	1 to put into reset, 0 to take out of reset
123  */
124 void reset_set_enable(enum periph_id periph_id, int enable);
125 
126 
127 /* CLK_RST_CONTROLLER_RST_CPU_CMPLX_SET/CLR_0 */
128 enum crc_reset_id {
129 	/* Things we can hold in reset for each CPU */
130 	crc_rst_cpu = 1,
131 	crc_rst_de = 1 << 2,	/* What is de? */
132 	crc_rst_watchdog = 1 << 3,
133 	crc_rst_debug = 1 << 4,
134 };
135 
136 /**
137  * Put parts of the CPU complex into or out of reset.\
138  *
139  * @param cpu		cpu number (0 or 1 on Tegra2, 0-3 on Tegra3)
140  * @param which		which parts of the complex to affect (OR of crc_reset_id)
141  * @param reset		1 to assert reset, 0 to de-assert
142  */
143 void reset_cmplx_set_enable(int cpu, int which, int reset);
144 
145 /**
146  * Set the source for a peripheral clock. This plus the divisor sets the
147  * clock rate. You need to look up the datasheet to see the meaning of the
148  * source parameter as it changes for each peripheral.
149  *
150  * Warning: This function is only for use pre-relocation. Please use
151  * clock_start_periph_pll() instead.
152  *
153  * @param periph_id	peripheral to adjust
154  * @param source	source clock (0, 1, 2 or 3)
155  */
156 void clock_ll_set_source(enum periph_id periph_id, unsigned source);
157 
158 /**
159  * Set the source and divisor for a peripheral clock. This sets the
160  * clock rate. You need to look up the datasheet to see the meaning of the
161  * source parameter as it changes for each peripheral.
162  *
163  * Warning: This function is only for use pre-relocation. Please use
164  * clock_start_periph_pll() instead.
165  *
166  * @param periph_id	peripheral to adjust
167  * @param source	source clock (0, 1, 2 or 3)
168  * @param divisor	divisor value to use
169  */
170 void clock_ll_set_source_divisor(enum periph_id periph_id, unsigned source,
171 		unsigned divisor);
172 
173 /**
174  * Start a peripheral PLL clock at the given rate. This also resets the
175  * peripheral.
176  *
177  * @param periph_id	peripheral to start
178  * @param parent	PLL id of required parent clock
179  * @param rate		Required clock rate in Hz
180  * @return rate selected in Hz, or -1U if something went wrong
181  */
182 unsigned clock_start_periph_pll(enum periph_id periph_id,
183 		enum clock_id parent, unsigned rate);
184 
185 /**
186  * Returns the rate of a peripheral clock in Hz. Since the caller almost
187  * certainly knows the parent clock (having just set it) we require that
188  * this be passed in so we don't need to work it out.
189  *
190  * @param periph_id	peripheral to start
191  * @param parent	PLL id of parent clock (used to calculate rate, you
192  *			must know this!)
193  * @return clock rate of peripheral in Hz
194  */
195 unsigned long clock_get_periph_rate(enum periph_id periph_id,
196 		enum clock_id parent);
197 
198 /**
199  * Adjust peripheral PLL clock to the given rate. This does not reset the
200  * peripheral. If a second stage divisor is not available, pass NULL for
201  * extra_div. If it is available, then this parameter will return the
202  * divisor selected (which will be a power of 2 from 1 to 256).
203  *
204  * @param periph_id	peripheral to start
205  * @param parent	PLL id of required parent clock
206  * @param rate		Required clock rate in Hz
207  * @param extra_div	value for the second-stage divisor (NULL if one is
208 			not available)
209  * @return rate selected in Hz, or -1U if something went wrong
210  */
211 unsigned clock_adjust_periph_pll_div(enum periph_id periph_id,
212 		enum clock_id parent, unsigned rate, int *extra_div);
213 
214 /**
215  * Returns the clock rate of a specified clock, in Hz.
216  *
217  * @param parent	PLL id of clock to check
218  * @return rate of clock in Hz
219  */
220 unsigned clock_get_rate(enum clock_id clkid);
221 
222 /**
223  * Start up a UART using low-level calls
224  *
225  * Prior to relocation clock_start_periph_pll() cannot be called. This
226  * function provides a way to set up a UART using low-level calls which
227  * do not require BSS.
228  *
229  * @param periph_id	Peripheral ID of UART to enable (e,g, PERIPH_ID_UART1)
230  */
231 void clock_ll_start_uart(enum periph_id periph_id);
232 
233 /**
234  * Decode a peripheral ID from a device tree node.
235  *
236  * This works by looking up the peripheral's 'clocks' node and reading out
237  * the second cell, which is the clock number / peripheral ID.
238  *
239  * @param blob		FDT blob to use
240  * @param node		Node to look at
241  * @return peripheral ID, or PERIPH_ID_NONE if none
242  */
243 enum periph_id clock_decode_periph_id(const void *blob, int node);
244 
245 /**
246  * Checks if the oscillator bypass is enabled (XOBP bit)
247  *
248  * @return 1 if bypass is enabled, 0 if not
249  */
250 int clock_get_osc_bypass(void);
251 
252 /*
253  * Checks that clocks are valid and prints a warning if not
254  *
255  * @return 0 if ok, -1 on error
256  */
257 int clock_verify(void);
258 
259 /* Initialize the clocks */
260 void clock_init(void);
261 
262 /* Initialize the PLLs */
263 void clock_early_init(void);
264 
265 /* Returns a pointer to the clock source register for a peripheral */
266 u32 *get_periph_source_reg(enum periph_id periph_id);
267 
268 /**
269  * Given a peripheral ID and the required source clock, this returns which
270  * value should be programmed into the source mux for that peripheral.
271  *
272  * There is special code here to handle the one source type with 5 sources.
273  *
274  * @param periph_id     peripheral to start
275  * @param source        PLL id of required parent clock
276  * @param mux_bits      Set to number of bits in mux register: 2 or 4
277  * @param divider_bits  Set to number of divider bits (8 or 16)
278  * @return mux value (0-4, or -1 if not found)
279  */
280 int get_periph_clock_source(enum periph_id periph_id,
281 		enum clock_id parent, int *mux_bits, int *divider_bits);
282 
283 /*
284  * Convert a device tree clock ID to our peripheral ID. They are mostly
285  * the same but we are very cautious so we check that a valid clock ID is
286  * provided.
287  *
288  * @param clk_id        Clock ID according to tegra30 device tree binding
289  * @return peripheral ID, or PERIPH_ID_NONE if the clock ID is invalid
290  */
291 enum periph_id clk_id_to_periph_id(int clk_id);
292 
293 /**
294  * Set the output frequency you want for each PLL clock.
295  * PLL output frequencies are programmed by setting their N, M and P values.
296  * The governing equations are:
297  *     VCO = (Fi / m) * n, Fo = VCO / (2^p)
298  *     where Fo is the output frequency from the PLL.
299  * Example: Set the output frequency to 216Mhz(Fo) with 12Mhz OSC(Fi)
300  *     216Mhz = ((12Mhz / m) * n) / (2^p) so n=432,m=12,p=1
301  * Please see Tegra TRM section 5.3 to get the detail for PLL Programming
302  *
303  * @param n PLL feedback divider(DIVN)
304  * @param m PLL input divider(DIVN)
305  * @param p post divider(DIVP)
306  * @param cpcon base PLL charge pump(CPCON)
307  * @return 0 if ok, -1 on error (the requested PLL is incorrect and cannot
308  *              be overriden), 1 if PLL is already correct
309  */
310 int clock_set_rate(enum clock_id clkid, u32 n, u32 m, u32 p, u32 cpcon);
311 
312 /* return 1 if a peripheral ID is in range */
313 #define clock_type_id_isvalid(id) ((id) >= 0 && \
314 		(id) < CLOCK_TYPE_COUNT)
315 
316 /* return 1 if a periphc_internal_id is in range */
317 #define periphc_internal_id_isvalid(id) ((id) >= 0 && \
318 		(id) < PERIPHC_COUNT)
319 
320 #endif  /* _TEGRA_CLOCK_H_ */
321