linux/drivers/pwm/pwm-pxa.c

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/*
* drivers/pwm/pwm-pxa.c
*
* simple driver for PWM (Pulse Width Modulator) controller
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 2008-02-13 initial version
* eric miao <eric.miao@marvell.com>
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/pwm.h>
#include <asm/div64.h>
#define HAS_SECONDARY_PWM 0x10
#define PWM_ID_BASE(d) ((d) & 0xf)
static const struct platform_device_id pwm_id_table[] = {
/* PWM has_secondary_pwm? */
{ "pxa25x-pwm", 0 },
{ "pxa27x-pwm", 0 | HAS_SECONDARY_PWM },
{ "pxa168-pwm", 1 },
{ "pxa910-pwm", 1 },
{ },
};
MODULE_DEVICE_TABLE(platform, pwm_id_table);
/* PWM registers and bits definitions */
#define PWMCR (0x00)
#define PWMDCR (0x04)
#define PWMPCR (0x08)
#define PWMCR_SD (1 << 6)
#define PWMDCR_FD (1 << 10)
struct pxa_pwm_chip {
struct pwm_chip chip;
struct device *dev;
struct clk *clk;
int clk_enabled;
void __iomem *mmio_base;
};
static inline struct pxa_pwm_chip *to_pxa_pwm_chip(struct pwm_chip *chip)
{
return container_of(chip, struct pxa_pwm_chip, chip);
}
/*
* period_ns = 10^9 * (PRESCALE + 1) * (PV + 1) / PWM_CLK_RATE
* duty_ns = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE
*/
static int pxa_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_ns, int period_ns)
{
struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
unsigned long long c;
unsigned long period_cycles, prescale, pv, dc;
unsigned long offset;
int rc;
if (period_ns == 0 || duty_ns > period_ns)
return -EINVAL;
offset = pwm->hwpwm ? 0x10 : 0;
c = clk_get_rate(pc->clk);
c = c * period_ns;
do_div(c, 1000000000);
period_cycles = c;
if (period_cycles < 1)
period_cycles = 1;
prescale = (period_cycles - 1) / 1024;
pv = period_cycles / (prescale + 1) - 1;
if (prescale > 63)
return -EINVAL;
if (duty_ns == period_ns)
dc = PWMDCR_FD;
else
dc = (pv + 1) * duty_ns / period_ns;
/* NOTE: the clock to PWM has to be enabled first
* before writing to the registers
*/
rc = clk_prepare_enable(pc->clk);
if (rc < 0)
return rc;
writel(prescale, pc->mmio_base + offset + PWMCR);
writel(dc, pc->mmio_base + offset + PWMDCR);
writel(pv, pc->mmio_base + offset + PWMPCR);
clk_disable_unprepare(pc->clk);
return 0;
}
static int pxa_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
int rc = 0;
if (!pc->clk_enabled) {
rc = clk_prepare_enable(pc->clk);
if (!rc)
pc->clk_enabled++;
}
return rc;
}
static void pxa_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
if (pc->clk_enabled) {
clk_disable_unprepare(pc->clk);
pc->clk_enabled--;
}
}
static struct pwm_ops pxa_pwm_ops = {
.config = pxa_pwm_config,
.enable = pxa_pwm_enable,
.disable = pxa_pwm_disable,
.owner = THIS_MODULE,
};
static int __devinit pwm_probe(struct platform_device *pdev)
{
const struct platform_device_id *id = platform_get_device_id(pdev);
struct pxa_pwm_chip *pwm;
struct resource *r;
int ret = 0;
pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
if (pwm == NULL) {
dev_err(&pdev->dev, "failed to allocate memory\n");
return -ENOMEM;
}
pwm->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(pwm->clk))
return PTR_ERR(pwm->clk);
pwm->clk_enabled = 0;
pwm->chip.dev = &pdev->dev;
pwm->chip.ops = &pxa_pwm_ops;
pwm->chip.base = -1;
pwm->chip.npwm = (id->driver_data & HAS_SECONDARY_PWM) ? 2 : 1;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (r == NULL) {
dev_err(&pdev->dev, "no memory resource defined\n");
return -ENODEV;
}
pwm->mmio_base = devm_request_and_ioremap(&pdev->dev, r);
if (pwm->mmio_base == NULL)
return -EADDRNOTAVAIL;
ret = pwmchip_add(&pwm->chip);
if (ret < 0) {
dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
return ret;
}
platform_set_drvdata(pdev, pwm);
return 0;
}
static int __devexit pwm_remove(struct platform_device *pdev)
{
struct pxa_pwm_chip *chip;
chip = platform_get_drvdata(pdev);
if (chip == NULL)
return -ENODEV;
return pwmchip_remove(&chip->chip);
}
static struct platform_driver pwm_driver = {
.driver = {
.name = "pxa25x-pwm",
.owner = THIS_MODULE,
},
.probe = pwm_probe,
.remove = __devexit_p(pwm_remove),
.id_table = pwm_id_table,
};
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 v2");