linux/drivers/pwm/pwm-dwc.c
Raag Jadav 9e3440d2d5 pwm: dwc: simplify error handling
Simplify error handling in ->probe() function using dev_err_probe() helper
and while at it, drop error codes from the message to prevent duplication.

Signed-off-by: Raag Jadav <raag.jadav@intel.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Link: https://lore.kernel.org/r/20240219033835.11369-5-raag.jadav@intel.com
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2024-02-26 11:14:46 +01:00

149 lines
3.6 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"
/* Elkhart Lake */
static const struct dwc_pwm_info ehl_pwm_info = {
.nr = 2,
.size = 0x1000,
};
static int dwc_pwm_init_one(struct device *dev, void __iomem *base, unsigned int offset)
{
struct pwm_chip *chip;
struct dwc_pwm *dwc;
chip = dwc_pwm_alloc(dev);
if (IS_ERR(chip))
return PTR_ERR(chip);
dwc = to_dwc_pwm(chip);
dwc->base = base + offset;
return devm_pwmchip_add(dev, chip);
}
static int dwc_pwm_probe(struct pci_dev *pci, const struct pci_device_id *id)
{
const struct dwc_pwm_info *info;
struct device *dev = &pci->dev;
int i, ret;
ret = pcim_enable_device(pci);
if (ret)
return dev_err_probe(dev, ret, "Failed to enable device\n");
pci_set_master(pci);
ret = pcim_iomap_regions(pci, BIT(0), pci_name(pci));
if (ret)
return dev_err_probe(dev, ret, "Failed to iomap PCI BAR\n");
info = (const struct dwc_pwm_info *)id->driver_data;
for (i = 0; i < info->nr; i++) {
/*
* No need to check for pcim_iomap_table() failure,
* pcim_iomap_regions() already does it for us.
*/
ret = dwc_pwm_init_one(dev, pcim_iomap_table(pci)[0], i * info->size);
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 pwm_chip *chip = dev_get_drvdata(dev);
struct dwc_pwm *dwc = to_dwc_pwm(chip);
int i;
for (i = 0; i < DWC_TIMERS_TOTAL; i++) {
if (chip->pwms[i].state.enabled) {
dev_err(dev, "PWM %u in use by consumer (%s)\n",
i, 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 pwm_chip *chip = dev_get_drvdata(dev);
struct dwc_pwm *dwc = to_dwc_pwm(chip);
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), (kernel_ulong_t)&ehl_pwm_info },
{ } /* 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");