2 * Intel Low Power Subsystem PWM controller driver
4 * Copyright (C) 2014, Intel Corporation
5 * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
6 * Author: Chew Kean Ho <kean.ho.chew@intel.com>
7 * Author: Chang Rebecca Swee Fun <rebecca.swee.fun.chang@intel.com>
8 * Author: Chew Chiau Ee <chiau.ee.chew@intel.com>
9 * Author: Alan Cox <alan@linux.intel.com>
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
16 #include <linux/acpi.h>
17 #include <linux/device.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/pwm.h>
21 #include <linux/platform_device.h>
22 #include <linux/pci.h>
24 static int pci_drv
, plat_drv
; /* So we know which drivers registered */
26 #define PWM 0x00000000
27 #define PWM_ENABLE BIT(31)
28 #define PWM_SW_UPDATE BIT(30)
29 #define PWM_BASE_UNIT_SHIFT 8
30 #define PWM_BASE_UNIT_MASK 0x00ffff00
31 #define PWM_ON_TIME_DIV_MASK 0x000000ff
32 #define PWM_DIVISION_CORRECTION 0x2
33 #define PWM_LIMIT (0x8000 + PWM_DIVISION_CORRECTION)
34 #define NSECS_PER_SEC 1000000000UL
36 struct pwm_lpss_chip
{
39 unsigned long clk_rate
;
42 struct pwm_lpss_boardinfo
{
43 unsigned long clk_rate
;
47 static const struct pwm_lpss_boardinfo byt_info
= {
52 static const struct pwm_lpss_boardinfo bsw_info
= {
56 static inline struct pwm_lpss_chip
*to_lpwm(struct pwm_chip
*chip
)
58 return container_of(chip
, struct pwm_lpss_chip
, chip
);
61 static int pwm_lpss_config(struct pwm_chip
*chip
, struct pwm_device
*pwm
,
62 int duty_ns
, int period_ns
)
64 struct pwm_lpss_chip
*lpwm
= to_lpwm(chip
);
67 unsigned long long base_unit
, freq
= NSECS_PER_SEC
;
70 do_div(freq
, period_ns
);
72 /* The equation is: base_unit = ((freq / c) * 65536) + correction */
73 base_unit
= freq
* 65536;
80 base_unit
+= PWM_DIVISION_CORRECTION
;
81 if (base_unit
> PWM_LIMIT
)
86 on_time_div
= 255 - (255 * duty_ns
/ period_ns
);
88 ctrl
= readl(lpwm
->regs
+ PWM
);
89 ctrl
&= ~(PWM_BASE_UNIT_MASK
| PWM_ON_TIME_DIV_MASK
);
90 ctrl
|= (u16
) base_unit
<< PWM_BASE_UNIT_SHIFT
;
92 /* request PWM to update on next cycle */
93 ctrl
|= PWM_SW_UPDATE
;
94 writel(ctrl
, lpwm
->regs
+ PWM
);
99 static int pwm_lpss_enable(struct pwm_chip
*chip
, struct pwm_device
*pwm
)
101 struct pwm_lpss_chip
*lpwm
= to_lpwm(chip
);
104 ctrl
= readl(lpwm
->regs
+ PWM
);
105 writel(ctrl
| PWM_ENABLE
, lpwm
->regs
+ PWM
);
110 static void pwm_lpss_disable(struct pwm_chip
*chip
, struct pwm_device
*pwm
)
112 struct pwm_lpss_chip
*lpwm
= to_lpwm(chip
);
115 ctrl
= readl(lpwm
->regs
+ PWM
);
116 writel(ctrl
& ~PWM_ENABLE
, lpwm
->regs
+ PWM
);
119 static const struct pwm_ops pwm_lpss_ops
= {
120 .config
= pwm_lpss_config
,
121 .enable
= pwm_lpss_enable
,
122 .disable
= pwm_lpss_disable
,
123 .owner
= THIS_MODULE
,
126 static struct pwm_lpss_chip
*pwm_lpss_probe(struct device
*dev
,
128 const struct pwm_lpss_boardinfo
*info
)
130 struct pwm_lpss_chip
*lpwm
;
133 lpwm
= devm_kzalloc(dev
, sizeof(*lpwm
), GFP_KERNEL
);
135 return ERR_PTR(-ENOMEM
);
137 lpwm
->regs
= devm_ioremap_resource(dev
, r
);
138 if (IS_ERR(lpwm
->regs
))
139 return ERR_CAST(lpwm
->regs
);
141 lpwm
->clk_rate
= info
->clk_rate
;
142 lpwm
->chip
.dev
= dev
;
143 lpwm
->chip
.ops
= &pwm_lpss_ops
;
144 lpwm
->chip
.base
= -1;
147 ret
= pwmchip_add(&lpwm
->chip
);
149 dev_err(dev
, "failed to add PWM chip: %d\n", ret
);
156 static int pwm_lpss_remove(struct pwm_lpss_chip
*lpwm
)
160 ctrl
= readl(lpwm
->regs
+ PWM
);
161 writel(ctrl
& ~PWM_ENABLE
, lpwm
->regs
+ PWM
);
163 return pwmchip_remove(&lpwm
->chip
);
166 static int pwm_lpss_probe_pci(struct pci_dev
*pdev
,
167 const struct pci_device_id
*id
)
169 const struct pwm_lpss_boardinfo
*info
;
170 struct pwm_lpss_chip
*lpwm
;
173 err
= pci_enable_device(pdev
);
177 info
= (struct pwm_lpss_boardinfo
*)id
->driver_data
;
178 lpwm
= pwm_lpss_probe(&pdev
->dev
, &pdev
->resource
[0], info
);
180 return PTR_ERR(lpwm
);
182 pci_set_drvdata(pdev
, lpwm
);
186 static void pwm_lpss_remove_pci(struct pci_dev
*pdev
)
188 struct pwm_lpss_chip
*lpwm
= pci_get_drvdata(pdev
);
190 pwm_lpss_remove(lpwm
);
191 pci_disable_device(pdev
);
194 static struct pci_device_id pwm_lpss_pci_ids
[] = {
195 { PCI_VDEVICE(INTEL
, 0x0f08), (unsigned long)&byt_info
},
196 { PCI_VDEVICE(INTEL
, 0x0f09), (unsigned long)&byt_info
},
197 { PCI_VDEVICE(INTEL
, 0x2288), (unsigned long)&bsw_info
},
198 { PCI_VDEVICE(INTEL
, 0x2289), (unsigned long)&bsw_info
},
201 MODULE_DEVICE_TABLE(pci
, pwm_lpss_pci_ids
);
203 static struct pci_driver pwm_lpss_driver_pci
= {
205 .id_table
= pwm_lpss_pci_ids
,
206 .probe
= pwm_lpss_probe_pci
,
207 .remove
= pwm_lpss_remove_pci
,
210 static int pwm_lpss_probe_platform(struct platform_device
*pdev
)
212 const struct pwm_lpss_boardinfo
*info
;
213 const struct acpi_device_id
*id
;
214 struct pwm_lpss_chip
*lpwm
;
217 id
= acpi_match_device(pdev
->dev
.driver
->acpi_match_table
, &pdev
->dev
);
221 r
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
223 info
= (struct pwm_lpss_boardinfo
*)id
->driver_data
;
224 lpwm
= pwm_lpss_probe(&pdev
->dev
, r
, info
);
226 return PTR_ERR(lpwm
);
228 platform_set_drvdata(pdev
, lpwm
);
232 static int pwm_lpss_remove_platform(struct platform_device
*pdev
)
234 struct pwm_lpss_chip
*lpwm
= platform_get_drvdata(pdev
);
236 return pwm_lpss_remove(lpwm
);
239 static const struct acpi_device_id pwm_lpss_acpi_match
[] = {
240 { "80860F09", (unsigned long)&byt_info
},
241 { "80862288", (unsigned long)&bsw_info
},
244 MODULE_DEVICE_TABLE(acpi
, pwm_lpss_acpi_match
);
246 static struct platform_driver pwm_lpss_driver_platform
= {
249 .acpi_match_table
= pwm_lpss_acpi_match
,
251 .probe
= pwm_lpss_probe_platform
,
252 .remove
= pwm_lpss_remove_platform
,
255 static int __init
pwm_init(void)
257 pci_drv
= pci_register_driver(&pwm_lpss_driver_pci
);
258 plat_drv
= platform_driver_register(&pwm_lpss_driver_platform
);
259 if (pci_drv
&& plat_drv
)
264 module_init(pwm_init
);
266 static void __exit
pwm_exit(void)
269 pci_unregister_driver(&pwm_lpss_driver_pci
);
271 platform_driver_unregister(&pwm_lpss_driver_platform
);
273 module_exit(pwm_exit
);
275 MODULE_DESCRIPTION("PWM driver for Intel LPSS");
276 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
277 MODULE_LICENSE("GPL v2");
278 MODULE_ALIAS("platform:pwm-lpss");