2 * Copyright (C) 2014 Free Electrons
3 * Copyright (C) 2014 Atmel
5 * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as published by
9 * the Free Software Foundation.
11 * This program is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 * You should have received a copy of the GNU General Public License along with
17 * this program. If not, see <http://www.gnu.org/licenses/>.
20 #include <linux/clk.h>
21 #include <linux/delay.h>
22 #include <linux/mfd/atmel-hlcdc.h>
23 #include <linux/module.h>
24 #include <linux/platform_device.h>
25 #include <linux/pwm.h>
26 #include <linux/regmap.h>
28 #define ATMEL_HLCDC_PWMCVAL_MASK GENMASK(15, 8)
29 #define ATMEL_HLCDC_PWMCVAL(x) (((x) << 8) & ATMEL_HLCDC_PWMCVAL_MASK)
30 #define ATMEL_HLCDC_PWMPOL BIT(4)
31 #define ATMEL_HLCDC_PWMPS_MASK GENMASK(2, 0)
32 #define ATMEL_HLCDC_PWMPS_MAX 0x6
33 #define ATMEL_HLCDC_PWMPS(x) ((x) & ATMEL_HLCDC_PWMPS_MASK)
35 struct atmel_hlcdc_pwm_errata
{
36 bool slow_clk_erratum
;
37 bool div1_clk_erratum
;
40 struct atmel_hlcdc_pwm
{
42 struct atmel_hlcdc
*hlcdc
;
44 const struct atmel_hlcdc_pwm_errata
*errata
;
47 static inline struct atmel_hlcdc_pwm
*to_atmel_hlcdc_pwm(struct pwm_chip
*chip
)
49 return container_of(chip
, struct atmel_hlcdc_pwm
, chip
);
52 static int atmel_hlcdc_pwm_config(struct pwm_chip
*c
,
53 struct pwm_device
*pwm
,
54 int duty_ns
, int period_ns
)
56 struct atmel_hlcdc_pwm
*chip
= to_atmel_hlcdc_pwm(c
);
57 struct atmel_hlcdc
*hlcdc
= chip
->hlcdc
;
58 struct clk
*new_clk
= hlcdc
->slow_clk
;
59 u64 pwmcval
= duty_ns
* 256;
60 unsigned long clk_freq
;
65 if (!chip
->errata
|| !chip
->errata
->slow_clk_erratum
) {
66 clk_freq
= clk_get_rate(new_clk
);
67 clk_period_ns
= (u64
)NSEC_PER_SEC
* 256;
68 do_div(clk_period_ns
, clk_freq
);
71 /* Errata: cannot use slow clk on some IP revisions */
72 if ((chip
->errata
&& chip
->errata
->slow_clk_erratum
) ||
73 clk_period_ns
> period_ns
) {
74 new_clk
= hlcdc
->sys_clk
;
75 clk_freq
= clk_get_rate(new_clk
);
76 clk_period_ns
= (u64
)NSEC_PER_SEC
* 256;
77 do_div(clk_period_ns
, clk_freq
);
80 for (pres
= 0; pres
<= ATMEL_HLCDC_PWMPS_MAX
; pres
++) {
81 /* Errata: cannot divide by 1 on some IP revisions */
82 if (!pres
&& chip
->errata
&& chip
->errata
->div1_clk_erratum
)
85 if ((clk_period_ns
<< pres
) >= period_ns
)
89 if (pres
> ATMEL_HLCDC_PWMPS_MAX
)
92 pwmcfg
= ATMEL_HLCDC_PWMPS(pres
);
94 if (new_clk
!= chip
->cur_clk
) {
98 ret
= clk_prepare_enable(new_clk
);
102 clk_disable_unprepare(chip
->cur_clk
);
103 chip
->cur_clk
= new_clk
;
105 if (new_clk
== hlcdc
->sys_clk
)
106 gencfg
= ATMEL_HLCDC_CLKPWMSEL
;
108 ret
= regmap_update_bits(hlcdc
->regmap
, ATMEL_HLCDC_CFG(0),
109 ATMEL_HLCDC_CLKPWMSEL
, gencfg
);
114 do_div(pwmcval
, period_ns
);
117 * The PWM duty cycle is configurable from 0/256 to 255/256 of the
118 * period cycle. Hence we can't set a duty cycle occupying the
119 * whole period cycle if we're asked to.
120 * Set it to 255 if pwmcval is greater than 256.
125 pwmcfg
|= ATMEL_HLCDC_PWMCVAL(pwmcval
);
127 return regmap_update_bits(hlcdc
->regmap
, ATMEL_HLCDC_CFG(6),
128 ATMEL_HLCDC_PWMCVAL_MASK
|
129 ATMEL_HLCDC_PWMPS_MASK
,
133 static int atmel_hlcdc_pwm_set_polarity(struct pwm_chip
*c
,
134 struct pwm_device
*pwm
,
135 enum pwm_polarity polarity
)
137 struct atmel_hlcdc_pwm
*chip
= to_atmel_hlcdc_pwm(c
);
138 struct atmel_hlcdc
*hlcdc
= chip
->hlcdc
;
141 if (polarity
== PWM_POLARITY_NORMAL
)
142 cfg
= ATMEL_HLCDC_PWMPOL
;
144 return regmap_update_bits(hlcdc
->regmap
, ATMEL_HLCDC_CFG(6),
145 ATMEL_HLCDC_PWMPOL
, cfg
);
148 static int atmel_hlcdc_pwm_enable(struct pwm_chip
*c
, struct pwm_device
*pwm
)
150 struct atmel_hlcdc_pwm
*chip
= to_atmel_hlcdc_pwm(c
);
151 struct atmel_hlcdc
*hlcdc
= chip
->hlcdc
;
155 ret
= regmap_write(hlcdc
->regmap
, ATMEL_HLCDC_EN
, ATMEL_HLCDC_PWM
);
160 ret
= regmap_read(hlcdc
->regmap
, ATMEL_HLCDC_SR
, &status
);
164 if ((status
& ATMEL_HLCDC_PWM
) != 0)
173 static void atmel_hlcdc_pwm_disable(struct pwm_chip
*c
,
174 struct pwm_device
*pwm
)
176 struct atmel_hlcdc_pwm
*chip
= to_atmel_hlcdc_pwm(c
);
177 struct atmel_hlcdc
*hlcdc
= chip
->hlcdc
;
181 ret
= regmap_write(hlcdc
->regmap
, ATMEL_HLCDC_DIS
, ATMEL_HLCDC_PWM
);
186 ret
= regmap_read(hlcdc
->regmap
, ATMEL_HLCDC_SR
, &status
);
190 if ((status
& ATMEL_HLCDC_PWM
) == 0)
197 static const struct pwm_ops atmel_hlcdc_pwm_ops
= {
198 .config
= atmel_hlcdc_pwm_config
,
199 .set_polarity
= atmel_hlcdc_pwm_set_polarity
,
200 .enable
= atmel_hlcdc_pwm_enable
,
201 .disable
= atmel_hlcdc_pwm_disable
,
202 .owner
= THIS_MODULE
,
205 static const struct atmel_hlcdc_pwm_errata atmel_hlcdc_pwm_at91sam9x5_errata
= {
206 .slow_clk_erratum
= true,
209 static const struct atmel_hlcdc_pwm_errata atmel_hlcdc_pwm_sama5d3_errata
= {
210 .div1_clk_erratum
= true,
213 static const struct of_device_id atmel_hlcdc_dt_ids
[] = {
215 .compatible
= "atmel,at91sam9x5-hlcdc",
216 .data
= &atmel_hlcdc_pwm_at91sam9x5_errata
,
219 .compatible
= "atmel,sama5d3-hlcdc",
220 .data
= &atmel_hlcdc_pwm_sama5d3_errata
,
225 static int atmel_hlcdc_pwm_probe(struct platform_device
*pdev
)
227 const struct of_device_id
*match
;
228 struct device
*dev
= &pdev
->dev
;
229 struct atmel_hlcdc_pwm
*chip
;
230 struct atmel_hlcdc
*hlcdc
;
233 hlcdc
= dev_get_drvdata(dev
->parent
);
235 chip
= devm_kzalloc(dev
, sizeof(*chip
), GFP_KERNEL
);
239 ret
= clk_prepare_enable(hlcdc
->periph_clk
);
243 match
= of_match_node(atmel_hlcdc_dt_ids
, dev
->parent
->of_node
);
245 chip
->errata
= match
->data
;
248 chip
->chip
.ops
= &atmel_hlcdc_pwm_ops
;
249 chip
->chip
.dev
= dev
;
250 chip
->chip
.base
= -1;
252 chip
->chip
.of_xlate
= of_pwm_xlate_with_flags
;
253 chip
->chip
.of_pwm_n_cells
= 3;
254 chip
->chip
.can_sleep
= 1;
256 ret
= pwmchip_add(&chip
->chip
);
258 clk_disable_unprepare(hlcdc
->periph_clk
);
262 platform_set_drvdata(pdev
, chip
);
267 static int atmel_hlcdc_pwm_remove(struct platform_device
*pdev
)
269 struct atmel_hlcdc_pwm
*chip
= platform_get_drvdata(pdev
);
272 ret
= pwmchip_remove(&chip
->chip
);
276 clk_disable_unprepare(chip
->hlcdc
->periph_clk
);
281 static const struct of_device_id atmel_hlcdc_pwm_dt_ids
[] = {
282 { .compatible
= "atmel,hlcdc-pwm" },
286 static struct platform_driver atmel_hlcdc_pwm_driver
= {
288 .name
= "atmel-hlcdc-pwm",
289 .of_match_table
= atmel_hlcdc_pwm_dt_ids
,
291 .probe
= atmel_hlcdc_pwm_probe
,
292 .remove
= atmel_hlcdc_pwm_remove
,
294 module_platform_driver(atmel_hlcdc_pwm_driver
);
296 MODULE_ALIAS("platform:atmel-hlcdc-pwm");
297 MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
298 MODULE_DESCRIPTION("Atmel HLCDC PWM driver");
299 MODULE_LICENSE("GPL v2");