2 * Copyright (C) 2013 Freescale Semiconductor, Inc.
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.
10 #include <linux/cpu.h>
11 #include <linux/cpufreq.h>
12 #include <linux/err.h>
13 #include <linux/module.h>
15 #include <linux/of_address.h>
16 #include <linux/pm_opp.h>
17 #include <linux/platform_device.h>
18 #include <linux/regulator/consumer.h>
20 #define PU_SOC_VOLTAGE_NORMAL 1250000
21 #define PU_SOC_VOLTAGE_HIGH 1275000
22 #define FREQ_1P2_GHZ 1200000000
24 static struct regulator
*arm_reg
;
25 static struct regulator
*pu_reg
;
26 static struct regulator
*soc_reg
;
28 enum IMX6_CPUFREQ_CLKS
{
34 /* MX6UL requires two more clks */
38 #define IMX6Q_CPUFREQ_CLK_NUM 5
39 #define IMX6UL_CPUFREQ_CLK_NUM 7
42 static struct clk_bulk_data clks
[] = {
47 { .id
= "pll2_pfd2_396m" },
49 { .id
= "secondary_sel" },
52 static struct device
*cpu_dev
;
54 static struct cpufreq_frequency_table
*freq_table
;
55 static unsigned int max_freq
;
56 static unsigned int transition_latency
;
58 static u32
*imx6_soc_volt
;
59 static u32 soc_opp_count
;
61 static int imx6q_set_target(struct cpufreq_policy
*policy
, unsigned int index
)
63 struct dev_pm_opp
*opp
;
64 unsigned long freq_hz
, volt
, volt_old
;
65 unsigned int old_freq
, new_freq
;
66 bool pll1_sys_temp_enabled
= false;
69 new_freq
= freq_table
[index
].frequency
;
70 freq_hz
= new_freq
* 1000;
71 old_freq
= clk_get_rate(clks
[ARM
].clk
) / 1000;
73 opp
= dev_pm_opp_find_freq_ceil(cpu_dev
, &freq_hz
);
75 dev_err(cpu_dev
, "failed to find OPP for %ld\n", freq_hz
);
79 volt
= dev_pm_opp_get_voltage(opp
);
82 volt_old
= regulator_get_voltage(arm_reg
);
84 dev_dbg(cpu_dev
, "%u MHz, %ld mV --> %u MHz, %ld mV\n",
85 old_freq
/ 1000, volt_old
/ 1000,
86 new_freq
/ 1000, volt
/ 1000);
88 /* scaling up? scale voltage before frequency */
89 if (new_freq
> old_freq
) {
90 if (!IS_ERR(pu_reg
)) {
91 ret
= regulator_set_voltage_tol(pu_reg
, imx6_soc_volt
[index
], 0);
93 dev_err(cpu_dev
, "failed to scale vddpu up: %d\n", ret
);
97 ret
= regulator_set_voltage_tol(soc_reg
, imx6_soc_volt
[index
], 0);
99 dev_err(cpu_dev
, "failed to scale vddsoc up: %d\n", ret
);
102 ret
= regulator_set_voltage_tol(arm_reg
, volt
, 0);
105 "failed to scale vddarm up: %d\n", ret
);
111 * The setpoints are selected per PLL/PDF frequencies, so we need to
112 * reprogram PLL for frequency scaling. The procedure of reprogramming
114 * For i.MX6UL, it has a secondary clk mux, the cpu frequency change
115 * flow is slightly different from other i.MX6 OSC.
116 * The cpu frequeny change flow for i.MX6(except i.MX6UL) is as below:
117 * - Enable pll2_pfd2_396m_clk and reparent pll1_sw_clk to it
118 * - Reprogram pll1_sys_clk and reparent pll1_sw_clk back to it
119 * - Disable pll2_pfd2_396m_clk
121 if (of_machine_is_compatible("fsl,imx6ul") ||
122 of_machine_is_compatible("fsl,imx6ull")) {
124 * When changing pll1_sw_clk's parent to pll1_sys_clk,
125 * CPU may run at higher than 528MHz, this will lead to
126 * the system unstable if the voltage is lower than the
127 * voltage of 528MHz, so lower the CPU frequency to one
128 * half before changing CPU frequency.
130 clk_set_rate(clks
[ARM
].clk
, (old_freq
>> 1) * 1000);
131 clk_set_parent(clks
[PLL1_SW
].clk
, clks
[PLL1_SYS
].clk
);
132 if (freq_hz
> clk_get_rate(clks
[PLL2_PFD2_396M
].clk
))
133 clk_set_parent(clks
[SECONDARY_SEL
].clk
,
136 clk_set_parent(clks
[SECONDARY_SEL
].clk
,
137 clks
[PLL2_PFD2_396M
].clk
);
138 clk_set_parent(clks
[STEP
].clk
, clks
[SECONDARY_SEL
].clk
);
139 clk_set_parent(clks
[PLL1_SW
].clk
, clks
[STEP
].clk
);
140 if (freq_hz
> clk_get_rate(clks
[PLL2_BUS
].clk
)) {
141 clk_set_rate(clks
[PLL1_SYS
].clk
, new_freq
* 1000);
142 clk_set_parent(clks
[PLL1_SW
].clk
, clks
[PLL1_SYS
].clk
);
145 clk_set_parent(clks
[STEP
].clk
, clks
[PLL2_PFD2_396M
].clk
);
146 clk_set_parent(clks
[PLL1_SW
].clk
, clks
[STEP
].clk
);
147 if (freq_hz
> clk_get_rate(clks
[PLL2_PFD2_396M
].clk
)) {
148 clk_set_rate(clks
[PLL1_SYS
].clk
, new_freq
* 1000);
149 clk_set_parent(clks
[PLL1_SW
].clk
, clks
[PLL1_SYS
].clk
);
151 /* pll1_sys needs to be enabled for divider rate change to work. */
152 pll1_sys_temp_enabled
= true;
153 clk_prepare_enable(clks
[PLL1_SYS
].clk
);
157 /* Ensure the arm clock divider is what we expect */
158 ret
= clk_set_rate(clks
[ARM
].clk
, new_freq
* 1000);
160 dev_err(cpu_dev
, "failed to set clock rate: %d\n", ret
);
161 regulator_set_voltage_tol(arm_reg
, volt_old
, 0);
165 /* PLL1 is only needed until after ARM-PODF is set. */
166 if (pll1_sys_temp_enabled
)
167 clk_disable_unprepare(clks
[PLL1_SYS
].clk
);
169 /* scaling down? scale voltage after frequency */
170 if (new_freq
< old_freq
) {
171 ret
= regulator_set_voltage_tol(arm_reg
, volt
, 0);
174 "failed to scale vddarm down: %d\n", ret
);
177 ret
= regulator_set_voltage_tol(soc_reg
, imx6_soc_volt
[index
], 0);
179 dev_warn(cpu_dev
, "failed to scale vddsoc down: %d\n", ret
);
182 if (!IS_ERR(pu_reg
)) {
183 ret
= regulator_set_voltage_tol(pu_reg
, imx6_soc_volt
[index
], 0);
185 dev_warn(cpu_dev
, "failed to scale vddpu down: %d\n", ret
);
194 static int imx6q_cpufreq_init(struct cpufreq_policy
*policy
)
198 policy
->clk
= clks
[ARM
].clk
;
199 ret
= cpufreq_generic_init(policy
, freq_table
, transition_latency
);
200 policy
->suspend_freq
= max_freq
;
205 static struct cpufreq_driver imx6q_cpufreq_driver
= {
206 .flags
= CPUFREQ_NEED_INITIAL_FREQ_CHECK
,
207 .verify
= cpufreq_generic_frequency_table_verify
,
208 .target_index
= imx6q_set_target
,
209 .get
= cpufreq_generic_get
,
210 .init
= imx6q_cpufreq_init
,
211 .name
= "imx6q-cpufreq",
212 .attr
= cpufreq_generic_attr
,
213 .suspend
= cpufreq_generic_suspend
,
216 #define OCOTP_CFG3 0x440
217 #define OCOTP_CFG3_SPEED_SHIFT 16
218 #define OCOTP_CFG3_SPEED_1P2GHZ 0x3
219 #define OCOTP_CFG3_SPEED_996MHZ 0x2
220 #define OCOTP_CFG3_SPEED_852MHZ 0x1
222 static void imx6q_opp_check_speed_grading(struct device
*dev
)
224 struct device_node
*np
;
228 np
= of_find_compatible_node(NULL
, NULL
, "fsl,imx6q-ocotp");
232 base
= of_iomap(np
, 0);
234 dev_err(dev
, "failed to map ocotp\n");
239 * SPEED_GRADING[1:0] defines the max speed of ARM:
240 * 2b'11: 1200000000Hz;
241 * 2b'10: 996000000Hz;
242 * 2b'01: 852000000Hz; -- i.MX6Q Only, exclusive with 996MHz.
243 * 2b'00: 792000000Hz;
244 * We need to set the max speed of ARM according to fuse map.
246 val
= readl_relaxed(base
+ OCOTP_CFG3
);
247 val
>>= OCOTP_CFG3_SPEED_SHIFT
;
250 if (val
< OCOTP_CFG3_SPEED_996MHZ
)
251 if (dev_pm_opp_disable(dev
, 996000000))
252 dev_warn(dev
, "failed to disable 996MHz OPP\n");
254 if (of_machine_is_compatible("fsl,imx6q") ||
255 of_machine_is_compatible("fsl,imx6qp")) {
256 if (val
!= OCOTP_CFG3_SPEED_852MHZ
)
257 if (dev_pm_opp_disable(dev
, 852000000))
258 dev_warn(dev
, "failed to disable 852MHz OPP\n");
259 if (val
!= OCOTP_CFG3_SPEED_1P2GHZ
)
260 if (dev_pm_opp_disable(dev
, 1200000000))
261 dev_warn(dev
, "failed to disable 1.2GHz OPP\n");
268 #define OCOTP_CFG3_6UL_SPEED_696MHZ 0x2
269 #define OCOTP_CFG3_6ULL_SPEED_792MHZ 0x2
270 #define OCOTP_CFG3_6ULL_SPEED_900MHZ 0x3
272 static void imx6ul_opp_check_speed_grading(struct device
*dev
)
274 struct device_node
*np
;
278 np
= of_find_compatible_node(NULL
, NULL
, "fsl,imx6ul-ocotp");
282 base
= of_iomap(np
, 0);
284 dev_err(dev
, "failed to map ocotp\n");
289 * Speed GRADING[1:0] defines the max speed of ARM:
291 * 2b'01: 528000000Hz;
292 * 2b'10: 696000000Hz on i.MX6UL, 792000000Hz on i.MX6ULL;
293 * 2b'11: 900000000Hz on i.MX6ULL only;
294 * We need to set the max speed of ARM according to fuse map.
296 val
= readl_relaxed(base
+ OCOTP_CFG3
);
297 val
>>= OCOTP_CFG3_SPEED_SHIFT
;
300 if (of_machine_is_compatible("fsl,imx6ul")) {
301 if (val
!= OCOTP_CFG3_6UL_SPEED_696MHZ
)
302 if (dev_pm_opp_disable(dev
, 696000000))
303 dev_warn(dev
, "failed to disable 696MHz OPP\n");
306 if (of_machine_is_compatible("fsl,imx6ull")) {
307 if (val
!= OCOTP_CFG3_6ULL_SPEED_792MHZ
)
308 if (dev_pm_opp_disable(dev
, 792000000))
309 dev_warn(dev
, "failed to disable 792MHz OPP\n");
311 if (val
!= OCOTP_CFG3_6ULL_SPEED_900MHZ
)
312 if (dev_pm_opp_disable(dev
, 900000000))
313 dev_warn(dev
, "failed to disable 900MHz OPP\n");
321 static int imx6q_cpufreq_probe(struct platform_device
*pdev
)
323 struct device_node
*np
;
324 struct dev_pm_opp
*opp
;
325 unsigned long min_volt
, max_volt
;
327 const struct property
*prop
;
331 cpu_dev
= get_cpu_device(0);
333 pr_err("failed to get cpu0 device\n");
337 np
= of_node_get(cpu_dev
->of_node
);
339 dev_err(cpu_dev
, "failed to find cpu0 node\n");
343 if (of_machine_is_compatible("fsl,imx6ul") ||
344 of_machine_is_compatible("fsl,imx6ull"))
345 num_clks
= IMX6UL_CPUFREQ_CLK_NUM
;
347 num_clks
= IMX6Q_CPUFREQ_CLK_NUM
;
349 ret
= clk_bulk_get(cpu_dev
, num_clks
, clks
);
353 arm_reg
= regulator_get(cpu_dev
, "arm");
354 pu_reg
= regulator_get_optional(cpu_dev
, "pu");
355 soc_reg
= regulator_get(cpu_dev
, "soc");
356 if (PTR_ERR(arm_reg
) == -EPROBE_DEFER
||
357 PTR_ERR(soc_reg
) == -EPROBE_DEFER
||
358 PTR_ERR(pu_reg
) == -EPROBE_DEFER
) {
360 dev_dbg(cpu_dev
, "regulators not ready, defer\n");
363 if (IS_ERR(arm_reg
) || IS_ERR(soc_reg
)) {
364 dev_err(cpu_dev
, "failed to get regulators\n");
369 ret
= dev_pm_opp_of_add_table(cpu_dev
);
371 dev_err(cpu_dev
, "failed to init OPP table: %d\n", ret
);
375 if (of_machine_is_compatible("fsl,imx6ul") ||
376 of_machine_is_compatible("fsl,imx6ull"))
377 imx6ul_opp_check_speed_grading(cpu_dev
);
379 imx6q_opp_check_speed_grading(cpu_dev
);
381 /* Because we have added the OPPs here, we must free them */
383 num
= dev_pm_opp_get_opp_count(cpu_dev
);
386 dev_err(cpu_dev
, "no OPP table is found: %d\n", ret
);
390 ret
= dev_pm_opp_init_cpufreq_table(cpu_dev
, &freq_table
);
392 dev_err(cpu_dev
, "failed to init cpufreq table: %d\n", ret
);
396 /* Make imx6_soc_volt array's size same as arm opp number */
397 imx6_soc_volt
= devm_kcalloc(cpu_dev
, num
, sizeof(*imx6_soc_volt
),
399 if (imx6_soc_volt
== NULL
) {
401 goto free_freq_table
;
404 prop
= of_find_property(np
, "fsl,soc-operating-points", NULL
);
405 if (!prop
|| !prop
->value
)
409 * Each OPP is a set of tuples consisting of frequency and
410 * voltage like <freq-kHz vol-uV>.
412 nr
= prop
->length
/ sizeof(u32
);
413 if (nr
% 2 || (nr
/ 2) < num
)
416 for (j
= 0; j
< num
; j
++) {
418 for (i
= 0; i
< nr
/ 2; i
++) {
419 unsigned long freq
= be32_to_cpup(val
++);
420 unsigned long volt
= be32_to_cpup(val
++);
421 if (freq_table
[j
].frequency
== freq
) {
422 imx6_soc_volt
[soc_opp_count
++] = volt
;
429 /* use fixed soc opp volt if no valid soc opp info found in dtb */
430 if (soc_opp_count
!= num
) {
431 dev_warn(cpu_dev
, "can NOT find valid fsl,soc-operating-points property in dtb, use default value!\n");
432 for (j
= 0; j
< num
; j
++)
433 imx6_soc_volt
[j
] = PU_SOC_VOLTAGE_NORMAL
;
434 if (freq_table
[num
- 1].frequency
* 1000 == FREQ_1P2_GHZ
)
435 imx6_soc_volt
[num
- 1] = PU_SOC_VOLTAGE_HIGH
;
438 if (of_property_read_u32(np
, "clock-latency", &transition_latency
))
439 transition_latency
= CPUFREQ_ETERNAL
;
442 * Calculate the ramp time for max voltage change in the
443 * VDDSOC and VDDPU regulators.
445 ret
= regulator_set_voltage_time(soc_reg
, imx6_soc_volt
[0], imx6_soc_volt
[num
- 1]);
447 transition_latency
+= ret
* 1000;
448 if (!IS_ERR(pu_reg
)) {
449 ret
= regulator_set_voltage_time(pu_reg
, imx6_soc_volt
[0], imx6_soc_volt
[num
- 1]);
451 transition_latency
+= ret
* 1000;
455 * OPP is maintained in order of increasing frequency, and
456 * freq_table initialised from OPP is therefore sorted in the
459 max_freq
= freq_table
[--num
].frequency
;
460 opp
= dev_pm_opp_find_freq_exact(cpu_dev
,
461 freq_table
[0].frequency
* 1000, true);
462 min_volt
= dev_pm_opp_get_voltage(opp
);
464 opp
= dev_pm_opp_find_freq_exact(cpu_dev
, max_freq
* 1000, true);
465 max_volt
= dev_pm_opp_get_voltage(opp
);
468 ret
= regulator_set_voltage_time(arm_reg
, min_volt
, max_volt
);
470 transition_latency
+= ret
* 1000;
472 ret
= cpufreq_register_driver(&imx6q_cpufreq_driver
);
474 dev_err(cpu_dev
, "failed register driver: %d\n", ret
);
475 goto free_freq_table
;
482 dev_pm_opp_free_cpufreq_table(cpu_dev
, &freq_table
);
485 dev_pm_opp_of_remove_table(cpu_dev
);
487 if (!IS_ERR(arm_reg
))
488 regulator_put(arm_reg
);
490 regulator_put(pu_reg
);
491 if (!IS_ERR(soc_reg
))
492 regulator_put(soc_reg
);
494 clk_bulk_put(num_clks
, clks
);
501 static int imx6q_cpufreq_remove(struct platform_device
*pdev
)
503 cpufreq_unregister_driver(&imx6q_cpufreq_driver
);
504 dev_pm_opp_free_cpufreq_table(cpu_dev
, &freq_table
);
506 dev_pm_opp_of_remove_table(cpu_dev
);
507 regulator_put(arm_reg
);
509 regulator_put(pu_reg
);
510 regulator_put(soc_reg
);
512 clk_bulk_put(num_clks
, clks
);
517 static struct platform_driver imx6q_cpufreq_platdrv
= {
519 .name
= "imx6q-cpufreq",
521 .probe
= imx6q_cpufreq_probe
,
522 .remove
= imx6q_cpufreq_remove
,
524 module_platform_driver(imx6q_cpufreq_platdrv
);
526 MODULE_ALIAS("platform:imx6q-cpufreq");
527 MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
528 MODULE_DESCRIPTION("Freescale i.MX6Q cpufreq driver");
529 MODULE_LICENSE("GPL");