4 * Copyright (C) 2012 Texas Instruments, Inc. - http://www.ti.com/
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
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.
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., 675 Mass Ave, Cambridge, MA 02139, USA.
21 #include <linux/module.h>
22 #include <linux/platform_device.h>
23 #include <linux/pwm.h>
25 #include <linux/err.h>
26 #include <linux/clk.h>
27 #include <linux/pm_runtime.h>
29 /* EHRPWM registers and bits definitions */
31 /* Time base module registers */
35 #define TBCTL_RUN_MASK (BIT(15) | BIT(14))
36 #define TBCTL_STOP_NEXT 0
37 #define TBCTL_STOP_ON_CYCLE BIT(14)
38 #define TBCTL_FREE_RUN (BIT(15) | BIT(14))
39 #define TBCTL_PRDLD_MASK BIT(3)
40 #define TBCTL_PRDLD_SHDW 0
41 #define TBCTL_PRDLD_IMDT BIT(3)
42 #define TBCTL_CLKDIV_MASK (BIT(12) | BIT(11) | BIT(10) | BIT(9) | \
44 #define TBCTL_CTRMODE_MASK (BIT(1) | BIT(0))
45 #define TBCTL_CTRMODE_UP 0
46 #define TBCTL_CTRMODE_DOWN BIT(0)
47 #define TBCTL_CTRMODE_UPDOWN BIT(1)
48 #define TBCTL_CTRMODE_FREEZE (BIT(1) | BIT(0))
50 #define TBCTL_HSPCLKDIV_SHIFT 7
51 #define TBCTL_CLKDIV_SHIFT 10
54 #define HSPCLKDIV_MAX 7
55 #define PERIOD_MAX 0xFFFF
57 /* compare module registers */
61 /* Action qualifier module registers */
67 #define AQCTL_CBU_MASK (BIT(9) | BIT(8))
68 #define AQCTL_CBU_FRCLOW BIT(8)
69 #define AQCTL_CBU_FRCHIGH BIT(9)
70 #define AQCTL_CBU_FRCTOGGLE (BIT(9) | BIT(8))
71 #define AQCTL_CAU_MASK (BIT(5) | BIT(4))
72 #define AQCTL_CAU_FRCLOW BIT(4)
73 #define AQCTL_CAU_FRCHIGH BIT(5)
74 #define AQCTL_CAU_FRCTOGGLE (BIT(5) | BIT(4))
75 #define AQCTL_PRD_MASK (BIT(3) | BIT(2))
76 #define AQCTL_PRD_FRCLOW BIT(2)
77 #define AQCTL_PRD_FRCHIGH BIT(3)
78 #define AQCTL_PRD_FRCTOGGLE (BIT(3) | BIT(2))
79 #define AQCTL_ZRO_MASK (BIT(1) | BIT(0))
80 #define AQCTL_ZRO_FRCLOW BIT(0)
81 #define AQCTL_ZRO_FRCHIGH BIT(1)
82 #define AQCTL_ZRO_FRCTOGGLE (BIT(1) | BIT(0))
84 #define AQCTL_CHANA_POLNORMAL (AQCTL_CAU_FRCLOW | AQCTL_PRD_FRCHIGH | \
86 #define AQCTL_CHANA_POLINVERSED (AQCTL_CAU_FRCHIGH | AQCTL_PRD_FRCLOW | \
88 #define AQCTL_CHANB_POLNORMAL (AQCTL_CBU_FRCLOW | AQCTL_PRD_FRCHIGH | \
90 #define AQCTL_CHANB_POLINVERSED (AQCTL_CBU_FRCHIGH | AQCTL_PRD_FRCLOW | \
93 #define AQSFRC_RLDCSF_MASK (BIT(7) | BIT(6))
94 #define AQSFRC_RLDCSF_ZRO 0
95 #define AQSFRC_RLDCSF_PRD BIT(6)
96 #define AQSFRC_RLDCSF_ZROPRD BIT(7)
97 #define AQSFRC_RLDCSF_IMDT (BIT(7) | BIT(6))
99 #define AQCSFRC_CSFB_MASK (BIT(3) | BIT(2))
100 #define AQCSFRC_CSFB_FRCDIS 0
101 #define AQCSFRC_CSFB_FRCLOW BIT(2)
102 #define AQCSFRC_CSFB_FRCHIGH BIT(3)
103 #define AQCSFRC_CSFB_DISSWFRC (BIT(3) | BIT(2))
104 #define AQCSFRC_CSFA_MASK (BIT(1) | BIT(0))
105 #define AQCSFRC_CSFA_FRCDIS 0
106 #define AQCSFRC_CSFA_FRCLOW BIT(0)
107 #define AQCSFRC_CSFA_FRCHIGH BIT(1)
108 #define AQCSFRC_CSFA_DISSWFRC (BIT(1) | BIT(0))
110 #define NUM_PWM_CHANNEL 2 /* EHRPWM channels */
112 struct ehrpwm_pwm_chip {
113 struct pwm_chip chip;
114 unsigned int clk_rate;
115 void __iomem *mmio_base;
116 unsigned long period_cycles[NUM_PWM_CHANNEL];
117 enum pwm_polarity polarity[NUM_PWM_CHANNEL];
121 static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
123 return container_of(chip, struct ehrpwm_pwm_chip, chip);
126 static void ehrpwm_write(void *base, int offset, unsigned int val)
128 writew(val & 0xFFFF, base + offset);
131 static void ehrpwm_modify(void *base, int offset,
132 unsigned short mask, unsigned short val)
134 unsigned short regval;
136 regval = readw(base + offset);
138 regval |= val & mask;
139 writew(regval, base + offset);
143 * set_prescale_div - Set up the prescaler divider function
144 * @rqst_prescaler: prescaler value min
145 * @prescale_div: prescaler value set
146 * @tb_clk_div: Time Base Control prescaler bits
148 static int set_prescale_div(unsigned long rqst_prescaler,
149 unsigned short *prescale_div, unsigned short *tb_clk_div)
151 unsigned int clkdiv, hspclkdiv;
153 for (clkdiv = 0; clkdiv <= CLKDIV_MAX; clkdiv++) {
154 for (hspclkdiv = 0; hspclkdiv <= HSPCLKDIV_MAX; hspclkdiv++) {
157 * calculations for prescaler value :
158 * prescale_div = HSPCLKDIVIDER * CLKDIVIDER.
159 * HSPCLKDIVIDER = 2 ** hspclkdiv
160 * CLKDIVIDER = (1), if clkdiv == 0 *OR*
161 * (2 * clkdiv), if clkdiv != 0
163 * Configure prescale_div value such that period
164 * register value is less than 65535.
167 *prescale_div = (1 << clkdiv) *
168 (hspclkdiv ? (hspclkdiv * 2) : 1);
169 if (*prescale_div > rqst_prescaler) {
170 *tb_clk_div = (clkdiv << TBCTL_CLKDIV_SHIFT) |
171 (hspclkdiv << TBCTL_HSPCLKDIV_SHIFT);
179 static void configure_polarity(struct ehrpwm_pwm_chip *pc, int chan)
182 unsigned short aqctl_val, aqctl_mask;
185 * Configure PWM output to HIGH/LOW level on counter
186 * reaches compare register value and LOW/HIGH level
187 * on counter value reaches period register value and
188 * zero value on counter
192 aqctl_mask = AQCTL_CBU_MASK;
194 if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
195 aqctl_val = AQCTL_CHANB_POLINVERSED;
197 aqctl_val = AQCTL_CHANB_POLNORMAL;
200 aqctl_mask = AQCTL_CAU_MASK;
202 if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
203 aqctl_val = AQCTL_CHANA_POLINVERSED;
205 aqctl_val = AQCTL_CHANA_POLNORMAL;
208 aqctl_mask |= AQCTL_PRD_MASK | AQCTL_ZRO_MASK;
209 ehrpwm_modify(pc->mmio_base, aqctl_reg, aqctl_mask, aqctl_val);
213 * period_ns = 10^9 * (ps_divval * period_cycles) / PWM_CLK_RATE
214 * duty_ns = 10^9 * (ps_divval * duty_cycles) / PWM_CLK_RATE
216 static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
217 int duty_ns, int period_ns)
219 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
220 unsigned long long c;
221 unsigned long period_cycles, duty_cycles;
222 unsigned short ps_divval, tb_divval;
225 if (period_ns > NSEC_PER_SEC)
230 do_div(c, NSEC_PER_SEC);
231 period_cycles = (unsigned long)c;
233 if (period_cycles < 1) {
239 do_div(c, NSEC_PER_SEC);
240 duty_cycles = (unsigned long)c;
244 * Period values should be same for multiple PWM channels as IP uses
245 * same period register for multiple channels.
247 for (i = 0; i < NUM_PWM_CHANNEL; i++) {
248 if (pc->period_cycles[i] &&
249 (pc->period_cycles[i] != period_cycles)) {
251 * Allow channel to reconfigure period if no other
252 * channels being configured.
257 dev_err(chip->dev, "Period value conflicts with channel %d\n",
263 pc->period_cycles[pwm->hwpwm] = period_cycles;
265 /* Configure clock prescaler to support Low frequency PWM wave */
266 if (set_prescale_div(period_cycles/PERIOD_MAX, &ps_divval,
268 dev_err(chip->dev, "Unsupported values\n");
272 pm_runtime_get_sync(chip->dev);
274 /* Update clock prescaler values */
275 ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CLKDIV_MASK, tb_divval);
277 /* Update period & duty cycle with presacler division */
278 period_cycles = period_cycles / ps_divval;
279 duty_cycles = duty_cycles / ps_divval;
281 /* Configure shadow loading on Period register */
282 ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_PRDLD_MASK, TBCTL_PRDLD_SHDW);
284 ehrpwm_write(pc->mmio_base, TBPRD, period_cycles);
286 /* Configure ehrpwm counter for up-count mode */
287 ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CTRMODE_MASK,
291 /* Channel 1 configured with compare B register */
294 /* Channel 0 configured with compare A register */
297 ehrpwm_write(pc->mmio_base, cmp_reg, duty_cycles);
299 pm_runtime_put_sync(chip->dev);
303 static int ehrpwm_pwm_set_polarity(struct pwm_chip *chip,
304 struct pwm_device *pwm, enum pwm_polarity polarity)
306 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
308 /* Configuration of polarity in hardware delayed, do at enable */
309 pc->polarity[pwm->hwpwm] = polarity;
313 static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
315 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
316 unsigned short aqcsfrc_val, aqcsfrc_mask;
318 /* Leave clock enabled on enabling PWM */
319 pm_runtime_get_sync(chip->dev);
321 /* Disabling Action Qualifier on PWM output */
323 aqcsfrc_val = AQCSFRC_CSFB_FRCDIS;
324 aqcsfrc_mask = AQCSFRC_CSFB_MASK;
326 aqcsfrc_val = AQCSFRC_CSFA_FRCDIS;
327 aqcsfrc_mask = AQCSFRC_CSFA_MASK;
330 /* Changes to shadow mode */
331 ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
334 ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
336 /* Channels polarity can be configured from action qualifier module */
337 configure_polarity(pc, pwm->hwpwm);
339 /* Enable TBCLK before enabling PWM device */
340 clk_enable(pc->tbclk);
342 /* Enable time counter for free_run */
343 ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_FREE_RUN);
347 static void ehrpwm_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
349 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
350 unsigned short aqcsfrc_val, aqcsfrc_mask;
352 /* Action Qualifier puts PWM output low forcefully */
354 aqcsfrc_val = AQCSFRC_CSFB_FRCLOW;
355 aqcsfrc_mask = AQCSFRC_CSFB_MASK;
357 aqcsfrc_val = AQCSFRC_CSFA_FRCLOW;
358 aqcsfrc_mask = AQCSFRC_CSFA_MASK;
362 * Changes to immediate action on Action Qualifier. This puts
363 * Action Qualifier control on PWM output from next TBCLK
365 ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
368 ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
370 /* Disabling TBCLK on PWM disable */
371 clk_disable(pc->tbclk);
373 /* Stop Time base counter */
374 ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_STOP_NEXT);
376 /* Disable clock on PWM disable */
377 pm_runtime_put_sync(chip->dev);
380 static void ehrpwm_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
382 struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
384 if (test_bit(PWMF_ENABLED, &pwm->flags)) {
385 dev_warn(chip->dev, "Removing PWM device without disabling\n");
386 pm_runtime_put_sync(chip->dev);
389 /* set period value to zero on free */
390 pc->period_cycles[pwm->hwpwm] = 0;
393 static const struct pwm_ops ehrpwm_pwm_ops = {
394 .free = ehrpwm_pwm_free,
395 .config = ehrpwm_pwm_config,
396 .set_polarity = ehrpwm_pwm_set_polarity,
397 .enable = ehrpwm_pwm_enable,
398 .disable = ehrpwm_pwm_disable,
399 .owner = THIS_MODULE,
402 static int __devinit ehrpwm_pwm_probe(struct platform_device *pdev)
407 struct ehrpwm_pwm_chip *pc;
409 pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
411 dev_err(&pdev->dev, "failed to allocate memory\n");
415 clk = devm_clk_get(&pdev->dev, "fck");
417 dev_err(&pdev->dev, "failed to get clock\n");
421 pc->clk_rate = clk_get_rate(clk);
423 dev_err(&pdev->dev, "failed to get clock rate\n");
427 pc->chip.dev = &pdev->dev;
428 pc->chip.ops = &ehrpwm_pwm_ops;
430 pc->chip.npwm = NUM_PWM_CHANNEL;
432 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
434 dev_err(&pdev->dev, "no memory resource defined\n");
438 pc->mmio_base = devm_request_and_ioremap(&pdev->dev, r);
440 return -EADDRNOTAVAIL;
442 /* Acquire tbclk for Time Base EHRPWM submodule */
443 pc->tbclk = devm_clk_get(&pdev->dev, "tbclk");
444 if (IS_ERR(pc->tbclk)) {
445 dev_err(&pdev->dev, "Failed to get tbclk\n");
446 return PTR_ERR(pc->tbclk);
449 ret = pwmchip_add(&pc->chip);
451 dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
455 pm_runtime_enable(&pdev->dev);
456 platform_set_drvdata(pdev, pc);
460 static int __devexit ehrpwm_pwm_remove(struct platform_device *pdev)
462 struct ehrpwm_pwm_chip *pc = platform_get_drvdata(pdev);
464 pm_runtime_put_sync(&pdev->dev);
465 pm_runtime_disable(&pdev->dev);
466 return pwmchip_remove(&pc->chip);
469 static struct platform_driver ehrpwm_pwm_driver = {
473 .probe = ehrpwm_pwm_probe,
474 .remove = __devexit_p(ehrpwm_pwm_remove),
477 module_platform_driver(ehrpwm_pwm_driver);
479 MODULE_DESCRIPTION("EHRPWM PWM driver");
480 MODULE_AUTHOR("Texas Instruments");
481 MODULE_LICENSE("GPL");