Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[platform/adaptation/renesas_rcar/renesas_kernel.git] / drivers / pwm / pwm-mxs.c
1 /*
2  * Copyright 2012 Freescale Semiconductor, Inc.
3  *
4  * The code contained herein is licensed under the GNU General Public
5  * License. You may obtain a copy of the GNU General Public License
6  * Version 2 or later at the following locations:
7  *
8  * http://www.opensource.org/licenses/gpl-license.html
9  * http://www.gnu.org/copyleft/gpl.html
10  */
11
12 #include <linux/clk.h>
13 #include <linux/err.h>
14 #include <linux/io.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 #include <linux/of_address.h>
19 #include <linux/pinctrl/consumer.h>
20 #include <linux/platform_device.h>
21 #include <linux/pwm.h>
22 #include <linux/slab.h>
23 #include <linux/stmp_device.h>
24
25 #define SET     0x4
26 #define CLR     0x8
27 #define TOG     0xc
28
29 #define PWM_CTRL                0x0
30 #define PWM_ACTIVE0             0x10
31 #define PWM_PERIOD0             0x20
32 #define  PERIOD_PERIOD(p)       ((p) & 0xffff)
33 #define  PERIOD_PERIOD_MAX      0x10000
34 #define  PERIOD_ACTIVE_HIGH     (3 << 16)
35 #define  PERIOD_INACTIVE_LOW    (2 << 18)
36 #define  PERIOD_CDIV(div)       (((div) & 0x7) << 20)
37 #define  PERIOD_CDIV_MAX        8
38
39 struct mxs_pwm_chip {
40         struct pwm_chip chip;
41         struct device *dev;
42         struct clk *clk;
43         void __iomem *base;
44 };
45
46 #define to_mxs_pwm_chip(_chip) container_of(_chip, struct mxs_pwm_chip, chip)
47
48 static int mxs_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
49                           int duty_ns, int period_ns)
50 {
51         struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip);
52         int ret, div = 0;
53         unsigned int period_cycles, duty_cycles;
54         unsigned long rate;
55         unsigned long long c;
56
57         rate = clk_get_rate(mxs->clk);
58         while (1) {
59                 c = rate / (1 << div);
60                 c = c * period_ns;
61                 do_div(c, 1000000000);
62                 if (c < PERIOD_PERIOD_MAX)
63                         break;
64                 div++;
65                 if (div > PERIOD_CDIV_MAX)
66                         return -EINVAL;
67         }
68
69         period_cycles = c;
70         c *= duty_ns;
71         do_div(c, period_ns);
72         duty_cycles = c;
73
74         /*
75          * If the PWM channel is disabled, make sure to turn on the clock
76          * before writing the register. Otherwise, keep it enabled.
77          */
78         if (!test_bit(PWMF_ENABLED, &pwm->flags)) {
79                 ret = clk_prepare_enable(mxs->clk);
80                 if (ret)
81                         return ret;
82         }
83
84         writel(duty_cycles << 16,
85                         mxs->base + PWM_ACTIVE0 + pwm->hwpwm * 0x20);
86         writel(PERIOD_PERIOD(period_cycles) | PERIOD_ACTIVE_HIGH |
87                PERIOD_INACTIVE_LOW | PERIOD_CDIV(div),
88                         mxs->base + PWM_PERIOD0 + pwm->hwpwm * 0x20);
89
90         /*
91          * If the PWM is not enabled, turn the clock off again to save power.
92          */
93         if (!test_bit(PWMF_ENABLED, &pwm->flags))
94                 clk_disable_unprepare(mxs->clk);
95
96         return 0;
97 }
98
99 static int mxs_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
100 {
101         struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip);
102         int ret;
103
104         ret = clk_prepare_enable(mxs->clk);
105         if (ret)
106                 return ret;
107
108         writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + SET);
109
110         return 0;
111 }
112
113 static void mxs_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
114 {
115         struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip);
116
117         writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + CLR);
118
119         clk_disable_unprepare(mxs->clk);
120 }
121
122 static const struct pwm_ops mxs_pwm_ops = {
123         .config = mxs_pwm_config,
124         .enable = mxs_pwm_enable,
125         .disable = mxs_pwm_disable,
126         .owner = THIS_MODULE,
127 };
128
129 static int mxs_pwm_probe(struct platform_device *pdev)
130 {
131         struct device_node *np = pdev->dev.of_node;
132         struct mxs_pwm_chip *mxs;
133         struct resource *res;
134         struct pinctrl *pinctrl;
135         int ret;
136
137         mxs = devm_kzalloc(&pdev->dev, sizeof(*mxs), GFP_KERNEL);
138         if (!mxs)
139                 return -ENOMEM;
140
141         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
142         mxs->base = devm_request_and_ioremap(&pdev->dev, res);
143         if (!mxs->base)
144                 return -EADDRNOTAVAIL;
145
146         pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
147         if (IS_ERR(pinctrl))
148                 return PTR_ERR(pinctrl);
149
150         mxs->clk = devm_clk_get(&pdev->dev, NULL);
151         if (IS_ERR(mxs->clk))
152                 return PTR_ERR(mxs->clk);
153
154         mxs->chip.dev = &pdev->dev;
155         mxs->chip.ops = &mxs_pwm_ops;
156         mxs->chip.base = -1;
157         ret = of_property_read_u32(np, "fsl,pwm-number", &mxs->chip.npwm);
158         if (ret < 0) {
159                 dev_err(&pdev->dev, "failed to get pwm number: %d\n", ret);
160                 return ret;
161         }
162
163         ret = pwmchip_add(&mxs->chip);
164         if (ret < 0) {
165                 dev_err(&pdev->dev, "failed to add pwm chip %d\n", ret);
166                 return ret;
167         }
168
169         mxs->dev = &pdev->dev;
170         platform_set_drvdata(pdev, mxs);
171
172         stmp_reset_block(mxs->base);
173
174         return 0;
175 }
176
177 static int __devexit mxs_pwm_remove(struct platform_device *pdev)
178 {
179         struct mxs_pwm_chip *mxs = platform_get_drvdata(pdev);
180
181         return pwmchip_remove(&mxs->chip);
182 }
183
184 static struct of_device_id mxs_pwm_dt_ids[] = {
185         { .compatible = "fsl,imx23-pwm", },
186         { /* sentinel */ }
187 };
188 MODULE_DEVICE_TABLE(of, mxs_pwm_dt_ids);
189
190 static struct platform_driver mxs_pwm_driver = {
191         .driver = {
192                 .name = "mxs-pwm",
193                 .of_match_table = of_match_ptr(mxs_pwm_dt_ids),
194         },
195         .probe = mxs_pwm_probe,
196         .remove = __devexit_p(mxs_pwm_remove),
197 };
198 module_platform_driver(mxs_pwm_driver);
199
200 MODULE_ALIAS("platform:mxs-pwm");
201 MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
202 MODULE_DESCRIPTION("Freescale MXS PWM Driver");
203 MODULE_LICENSE("GPL v2");