mirror_ubuntu-kernels/drivers/pwm/pwm-dwc.c

134 lines
3.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* DesignWare PWM Controller driver (PCI part)
*
* Copyright (C) 2018-2020 Intel Corporation
*
* Author: Felipe Balbi (Intel)
* Author: Jarkko Nikula <jarkko.nikula@linux.intel.com>
* Author: Raymond Tan <raymond.tan@intel.com>
*
* Limitations:
* - The hardware cannot generate a 0 % or 100 % duty cycle. Both high and low
* periods are one or more input clock periods long.
*/
#define DEFAULT_MOUDLE_NAMESPACE dwc_pwm
#include <linux/bitops.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/pm_runtime.h>
#include <linux/pwm.h>
#include "pwm-dwc.h"
static int dwc_pwm_probe(struct pci_dev *pci, const struct pci_device_id *id)
{
struct device *dev = &pci->dev;
struct dwc_pwm *dwc;
int ret;
dwc = dwc_pwm_alloc(dev);
if (!dwc)
return -ENOMEM;
ret = pcim_enable_device(pci);
if (ret) {
dev_err(dev, "Failed to enable device (%pe)\n", ERR_PTR(ret));
return ret;
}
pci_set_master(pci);
ret = pcim_iomap_regions(pci, BIT(0), pci_name(pci));
if (ret) {
dev_err(dev, "Failed to iomap PCI BAR (%pe)\n", ERR_PTR(ret));
return ret;
}
dwc->base = pcim_iomap_table(pci)[0];
if (!dwc->base) {
dev_err(dev, "Base address missing\n");
return -ENOMEM;
}
ret = devm_pwmchip_add(dev, &dwc->chip);
if (ret)
return ret;
pm_runtime_put(dev);
pm_runtime_allow(dev);
return 0;
}
static void dwc_pwm_remove(struct pci_dev *pci)
{
pm_runtime_forbid(&pci->dev);
pm_runtime_get_noresume(&pci->dev);
}
static int dwc_pwm_suspend(struct device *dev)
{
struct pci_dev *pdev = container_of(dev, struct pci_dev, dev);
struct dwc_pwm *dwc = pci_get_drvdata(pdev);
int i;
for (i = 0; i < DWC_TIMERS_TOTAL; i++) {
if (dwc->chip.pwms[i].state.enabled) {
dev_err(dev, "PWM %u in use by consumer (%s)\n",
i, dwc->chip.pwms[i].label);
return -EBUSY;
}
dwc->ctx[i].cnt = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT(i));
dwc->ctx[i].cnt2 = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT2(i));
dwc->ctx[i].ctrl = dwc_pwm_readl(dwc, DWC_TIM_CTRL(i));
}
return 0;
}
static int dwc_pwm_resume(struct device *dev)
{
struct pci_dev *pdev = container_of(dev, struct pci_dev, dev);
struct dwc_pwm *dwc = pci_get_drvdata(pdev);
int i;
for (i = 0; i < DWC_TIMERS_TOTAL; i++) {
dwc_pwm_writel(dwc, dwc->ctx[i].cnt, DWC_TIM_LD_CNT(i));
dwc_pwm_writel(dwc, dwc->ctx[i].cnt2, DWC_TIM_LD_CNT2(i));
dwc_pwm_writel(dwc, dwc->ctx[i].ctrl, DWC_TIM_CTRL(i));
}
return 0;
}
static DEFINE_SIMPLE_DEV_PM_OPS(dwc_pwm_pm_ops, dwc_pwm_suspend, dwc_pwm_resume);
static const struct pci_device_id dwc_pwm_id_table[] = {
{ PCI_VDEVICE(INTEL, 0x4bb7) }, /* Elkhart Lake */
{ } /* Terminating Entry */
};
MODULE_DEVICE_TABLE(pci, dwc_pwm_id_table);
static struct pci_driver dwc_pwm_driver = {
.name = "pwm-dwc",
.probe = dwc_pwm_probe,
.remove = dwc_pwm_remove,
.id_table = dwc_pwm_id_table,
.driver = {
.pm = pm_sleep_ptr(&dwc_pwm_pm_ops),
},
};
module_pci_driver(dwc_pwm_driver);
MODULE_AUTHOR("Felipe Balbi (Intel)");
MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@linux.intel.com>");
MODULE_AUTHOR("Raymond Tan <raymond.tan@intel.com>");
MODULE_DESCRIPTION("DesignWare PWM Controller");
MODULE_LICENSE("GPL");