1// SPDX-License-Identifier: GPL-2.0
2/*
3 * DesignWare PWM Controller driver (PCI part)
4 *
5 * Copyright (C) 2018-2020 Intel Corporation
6 *
7 * Author: Felipe Balbi (Intel)
8 * Author: Jarkko Nikula <jarkko.nikula@linux.intel.com>
9 * Author: Raymond Tan <raymond.tan@intel.com>
10 *
11 * Limitations:
12 * - The hardware cannot generate a 0 % or 100 % duty cycle. Both high and low
13 * periods are one or more input clock periods long.
14 */
15
16#define DEFAULT_MOUDLE_NAMESPACE dwc_pwm
17
18#include <linux/bitops.h>
19#include <linux/export.h>
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/pci.h>
23#include <linux/pm_runtime.h>
24#include <linux/pwm.h>
25
26#include "pwm-dwc.h"
27
28/* Elkhart Lake */
29static const struct dwc_pwm_info ehl_pwm_info = {
30 .nr = 2,
31 .size = 0x1000,
32};
33
34static int dwc_pwm_init_one(struct device *dev, struct dwc_pwm_drvdata *ddata, unsigned int idx)
35{
36 struct pwm_chip *chip;
37 struct dwc_pwm *dwc;
38 int ret;
39
40 chip = dwc_pwm_alloc(dev);
41 if (IS_ERR(ptr: chip))
42 return PTR_ERR(ptr: chip);
43
44 dwc = to_dwc_pwm(chip);
45 dwc->base = ddata->io_base + (ddata->info->size * idx);
46
47 ret = devm_pwmchip_add(dev, chip);
48 if (ret)
49 return ret;
50
51 ddata->chips[idx] = chip;
52 return 0;
53}
54
55static int dwc_pwm_probe(struct pci_dev *pci, const struct pci_device_id *id)
56{
57 const struct dwc_pwm_info *info;
58 struct device *dev = &pci->dev;
59 struct dwc_pwm_drvdata *ddata;
60 unsigned int idx;
61 int ret;
62
63 ret = pcim_enable_device(pdev: pci);
64 if (ret)
65 return dev_err_probe(dev, err: ret, fmt: "Failed to enable device\n");
66
67 pci_set_master(dev: pci);
68
69 ret = pcim_iomap_regions(pdev: pci, BIT(0), name: pci_name(pdev: pci));
70 if (ret)
71 return dev_err_probe(dev, err: ret, fmt: "Failed to iomap PCI BAR\n");
72
73 info = (const struct dwc_pwm_info *)id->driver_data;
74 ddata = devm_kzalloc(dev, struct_size(ddata, chips, info->nr), GFP_KERNEL);
75 if (!ddata)
76 return -ENOMEM;
77
78 /*
79 * No need to check for pcim_iomap_table() failure,
80 * pcim_iomap_regions() already does it for us.
81 */
82 ddata->io_base = pcim_iomap_table(pdev: pci)[0];
83 ddata->info = info;
84
85 for (idx = 0; idx < ddata->info->nr; idx++) {
86 ret = dwc_pwm_init_one(dev, ddata, idx);
87 if (ret)
88 return ret;
89 }
90
91 dev_set_drvdata(dev, data: ddata);
92
93 pm_runtime_put(dev);
94 pm_runtime_allow(dev);
95
96 return 0;
97}
98
99static void dwc_pwm_remove(struct pci_dev *pci)
100{
101 pm_runtime_forbid(dev: &pci->dev);
102 pm_runtime_get_noresume(dev: &pci->dev);
103}
104
105static int dwc_pwm_suspend(struct device *dev)
106{
107 struct dwc_pwm_drvdata *ddata = dev_get_drvdata(dev);
108 unsigned int idx;
109
110 for (idx = 0; idx < ddata->info->nr; idx++) {
111 struct pwm_chip *chip = ddata->chips[idx];
112 struct dwc_pwm *dwc = to_dwc_pwm(chip);
113 unsigned int i;
114
115 for (i = 0; i < DWC_TIMERS_TOTAL; i++) {
116 if (chip->pwms[i].state.enabled) {
117 dev_err(dev, "PWM %u in use by consumer (%s)\n",
118 i, chip->pwms[i].label);
119 return -EBUSY;
120 }
121 dwc->ctx[i].cnt = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT(i));
122 dwc->ctx[i].cnt2 = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT2(i));
123 dwc->ctx[i].ctrl = dwc_pwm_readl(dwc, DWC_TIM_CTRL(i));
124 }
125 }
126
127 return 0;
128}
129
130static int dwc_pwm_resume(struct device *dev)
131{
132 struct dwc_pwm_drvdata *ddata = dev_get_drvdata(dev);
133 unsigned int idx;
134
135 for (idx = 0; idx < ddata->info->nr; idx++) {
136 struct pwm_chip *chip = ddata->chips[idx];
137 struct dwc_pwm *dwc = to_dwc_pwm(chip);
138 unsigned int i;
139
140 for (i = 0; i < DWC_TIMERS_TOTAL; i++) {
141 dwc_pwm_writel(dwc, value: dwc->ctx[i].cnt, DWC_TIM_LD_CNT(i));
142 dwc_pwm_writel(dwc, value: dwc->ctx[i].cnt2, DWC_TIM_LD_CNT2(i));
143 dwc_pwm_writel(dwc, value: dwc->ctx[i].ctrl, DWC_TIM_CTRL(i));
144 }
145 }
146
147 return 0;
148}
149
150static DEFINE_SIMPLE_DEV_PM_OPS(dwc_pwm_pm_ops, dwc_pwm_suspend, dwc_pwm_resume);
151
152static const struct pci_device_id dwc_pwm_id_table[] = {
153 { PCI_VDEVICE(INTEL, 0x4bb7), (kernel_ulong_t)&ehl_pwm_info },
154 { } /* Terminating Entry */
155};
156MODULE_DEVICE_TABLE(pci, dwc_pwm_id_table);
157
158static struct pci_driver dwc_pwm_driver = {
159 .name = "pwm-dwc",
160 .probe = dwc_pwm_probe,
161 .remove = dwc_pwm_remove,
162 .id_table = dwc_pwm_id_table,
163 .driver = {
164 .pm = pm_sleep_ptr(&dwc_pwm_pm_ops),
165 },
166};
167
168module_pci_driver(dwc_pwm_driver);
169
170MODULE_AUTHOR("Felipe Balbi (Intel)");
171MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@linux.intel.com>");
172MODULE_AUTHOR("Raymond Tan <raymond.tan@intel.com>");
173MODULE_DESCRIPTION("DesignWare PWM Controller");
174MODULE_LICENSE("GPL");
175

source code of linux/drivers/pwm/pwm-dwc.c