mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-15 06:36:44 +07:00
21f47fbc5b
This adds support for the family of Systems-on-Chip produced initially by VIA and now its subsidiary WonderMedia that have recently become widespread in lower-end Chinese ARM-based tablets and netbooks. Support is included for both VT8500 and WM8505, selectable by a configuration switch at kernel build time. Included are basic machine initialization files, register and interrupt definitions, support for the on-chip interrupt controller, high-precision OS timer, GPIO lines, necessary macros for early debug, pulse-width-modulated outputs control, as well as platform device configurations for the specific drivers implemented elsewhere. Signed-off-by: Alexey Charkov <alchark@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
266 lines
5.6 KiB
C
266 lines
5.6 KiB
C
/*
|
|
* arch/arm/mach-vt8500/pwm.c
|
|
*
|
|
* Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
|
|
*
|
|
* This software is licensed under the terms of the GNU General Public
|
|
* License version 2, as published by the Free Software Foundation, and
|
|
* may be copied, distributed, and modified under those terms.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/err.h>
|
|
#include <linux/io.h>
|
|
#include <linux/pwm.h>
|
|
#include <linux/delay.h>
|
|
|
|
#include <asm/div64.h>
|
|
|
|
#define VT8500_NR_PWMS 4
|
|
|
|
static DEFINE_MUTEX(pwm_lock);
|
|
static LIST_HEAD(pwm_list);
|
|
|
|
struct pwm_device {
|
|
struct list_head node;
|
|
struct platform_device *pdev;
|
|
|
|
const char *label;
|
|
|
|
void __iomem *regbase;
|
|
|
|
unsigned int use_count;
|
|
unsigned int pwm_id;
|
|
};
|
|
|
|
#define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
|
|
static inline void pwm_busy_wait(void __iomem *reg, u8 bitmask)
|
|
{
|
|
int loops = msecs_to_loops(10);
|
|
while ((readb(reg) & bitmask) && --loops)
|
|
cpu_relax();
|
|
|
|
if (unlikely(!loops))
|
|
pr_warning("Waiting for status bits 0x%x to clear timed out\n",
|
|
bitmask);
|
|
}
|
|
|
|
int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
|
|
{
|
|
unsigned long long c;
|
|
unsigned long period_cycles, prescale, pv, dc;
|
|
|
|
if (pwm == NULL || period_ns == 0 || duty_ns > period_ns)
|
|
return -EINVAL;
|
|
|
|
c = 25000000/2; /* wild guess --- need to implement clocks */
|
|
c = c * period_ns;
|
|
do_div(c, 1000000000);
|
|
period_cycles = c;
|
|
|
|
if (period_cycles < 1)
|
|
period_cycles = 1;
|
|
prescale = (period_cycles - 1) / 4096;
|
|
pv = period_cycles / (prescale + 1) - 1;
|
|
if (pv > 4095)
|
|
pv = 4095;
|
|
|
|
if (prescale > 1023)
|
|
return -EINVAL;
|
|
|
|
c = (unsigned long long)pv * duty_ns;
|
|
do_div(c, period_ns);
|
|
dc = c;
|
|
|
|
pwm_busy_wait(pwm->regbase + 0x40 + pwm->pwm_id, (1 << 1));
|
|
writel(prescale, pwm->regbase + 0x4 + (pwm->pwm_id << 4));
|
|
|
|
pwm_busy_wait(pwm->regbase + 0x40 + pwm->pwm_id, (1 << 2));
|
|
writel(pv, pwm->regbase + 0x8 + (pwm->pwm_id << 4));
|
|
|
|
pwm_busy_wait(pwm->regbase + 0x40 + pwm->pwm_id, (1 << 3));
|
|
writel(dc, pwm->regbase + 0xc + (pwm->pwm_id << 4));
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(pwm_config);
|
|
|
|
int pwm_enable(struct pwm_device *pwm)
|
|
{
|
|
pwm_busy_wait(pwm->regbase + 0x40 + pwm->pwm_id, (1 << 0));
|
|
writel(5, pwm->regbase + (pwm->pwm_id << 4));
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(pwm_enable);
|
|
|
|
void pwm_disable(struct pwm_device *pwm)
|
|
{
|
|
pwm_busy_wait(pwm->regbase + 0x40 + pwm->pwm_id, (1 << 0));
|
|
writel(0, pwm->regbase + (pwm->pwm_id << 4));
|
|
}
|
|
EXPORT_SYMBOL(pwm_disable);
|
|
|
|
struct pwm_device *pwm_request(int pwm_id, const char *label)
|
|
{
|
|
struct pwm_device *pwm;
|
|
int found = 0;
|
|
|
|
mutex_lock(&pwm_lock);
|
|
|
|
list_for_each_entry(pwm, &pwm_list, node) {
|
|
if (pwm->pwm_id == pwm_id) {
|
|
found = 1;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (found) {
|
|
if (pwm->use_count == 0) {
|
|
pwm->use_count++;
|
|
pwm->label = label;
|
|
} else {
|
|
pwm = ERR_PTR(-EBUSY);
|
|
}
|
|
} else {
|
|
pwm = ERR_PTR(-ENOENT);
|
|
}
|
|
|
|
mutex_unlock(&pwm_lock);
|
|
return pwm;
|
|
}
|
|
EXPORT_SYMBOL(pwm_request);
|
|
|
|
void pwm_free(struct pwm_device *pwm)
|
|
{
|
|
mutex_lock(&pwm_lock);
|
|
|
|
if (pwm->use_count) {
|
|
pwm->use_count--;
|
|
pwm->label = NULL;
|
|
} else {
|
|
pr_warning("PWM device already freed\n");
|
|
}
|
|
|
|
mutex_unlock(&pwm_lock);
|
|
}
|
|
EXPORT_SYMBOL(pwm_free);
|
|
|
|
static inline void __add_pwm(struct pwm_device *pwm)
|
|
{
|
|
mutex_lock(&pwm_lock);
|
|
list_add_tail(&pwm->node, &pwm_list);
|
|
mutex_unlock(&pwm_lock);
|
|
}
|
|
|
|
static int __devinit pwm_probe(struct platform_device *pdev)
|
|
{
|
|
struct pwm_device *pwms;
|
|
struct resource *r;
|
|
int ret = 0;
|
|
int i;
|
|
|
|
pwms = kzalloc(sizeof(struct pwm_device) * VT8500_NR_PWMS, GFP_KERNEL);
|
|
if (pwms == NULL) {
|
|
dev_err(&pdev->dev, "failed to allocate memory\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
for (i = 0; i < VT8500_NR_PWMS; i++) {
|
|
pwms[i].use_count = 0;
|
|
pwms[i].pwm_id = i;
|
|
pwms[i].pdev = pdev;
|
|
}
|
|
|
|
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
if (r == NULL) {
|
|
dev_err(&pdev->dev, "no memory resource defined\n");
|
|
ret = -ENODEV;
|
|
goto err_free;
|
|
}
|
|
|
|
r = request_mem_region(r->start, resource_size(r), pdev->name);
|
|
if (r == NULL) {
|
|
dev_err(&pdev->dev, "failed to request memory resource\n");
|
|
ret = -EBUSY;
|
|
goto err_free;
|
|
}
|
|
|
|
pwms[0].regbase = ioremap(r->start, resource_size(r));
|
|
if (pwms[0].regbase == NULL) {
|
|
dev_err(&pdev->dev, "failed to ioremap() registers\n");
|
|
ret = -ENODEV;
|
|
goto err_free_mem;
|
|
}
|
|
|
|
for (i = 1; i < VT8500_NR_PWMS; i++)
|
|
pwms[i].regbase = pwms[0].regbase;
|
|
|
|
for (i = 0; i < VT8500_NR_PWMS; i++)
|
|
__add_pwm(&pwms[i]);
|
|
|
|
platform_set_drvdata(pdev, pwms);
|
|
return 0;
|
|
|
|
err_free_mem:
|
|
release_mem_region(r->start, resource_size(r));
|
|
err_free:
|
|
kfree(pwms);
|
|
return ret;
|
|
}
|
|
|
|
static int __devexit pwm_remove(struct platform_device *pdev)
|
|
{
|
|
struct pwm_device *pwms;
|
|
struct resource *r;
|
|
int i;
|
|
|
|
pwms = platform_get_drvdata(pdev);
|
|
if (pwms == NULL)
|
|
return -ENODEV;
|
|
|
|
mutex_lock(&pwm_lock);
|
|
|
|
for (i = 0; i < VT8500_NR_PWMS; i++)
|
|
list_del(&pwms[i].node);
|
|
mutex_unlock(&pwm_lock);
|
|
|
|
iounmap(pwms[0].regbase);
|
|
|
|
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
release_mem_region(r->start, resource_size(r));
|
|
|
|
kfree(pwms);
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver pwm_driver = {
|
|
.driver = {
|
|
.name = "vt8500-pwm",
|
|
.owner = THIS_MODULE,
|
|
},
|
|
.probe = pwm_probe,
|
|
.remove = __devexit_p(pwm_remove),
|
|
};
|
|
|
|
static int __init pwm_init(void)
|
|
{
|
|
return platform_driver_register(&pwm_driver);
|
|
}
|
|
arch_initcall(pwm_init);
|
|
|
|
static void __exit pwm_exit(void)
|
|
{
|
|
platform_driver_unregister(&pwm_driver);
|
|
}
|
|
module_exit(pwm_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|