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authorIngo Molnar <mingo@kernel.org>2012-08-21 11:27:00 +0200
committerIngo Molnar <mingo@kernel.org>2012-08-21 11:27:00 +0200
commitbcada3d4b8c96b8792c2306f363992ca5ab9da42 (patch)
treee420679a5db6ea4e1694eef57f9abb6acac8d4d3 /drivers/pwm/pwm-vt8500.c
parent26198c21d1b286a084fe5d514a30bc7e6c712a34 (diff)
parent000078bc3ee69efb1124b8478c7527389a826074 (diff)
Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo: * Fix include order for bison/flex-generated C files, from Ben Hutchings * Build fixes and documentation corrections from David Ahern * Group parsing support, from Jiri Olsa * UI/gtk refactorings and improvements from Namhyung Kim * NULL deref fix for perf script, from Namhyung Kim * Assorted cleanups from Robert Richter * Let O= makes handle relative paths, from Steven Rostedt * perf script python fixes, from Feng Tang. * Improve 'perf lock' error message when the needed tracepoints are not present, from David Ahern. * Initial bash completion support, from Frederic Weisbecker * Allow building without libelf, from Namhyung Kim. * Support DWARF CFI based unwind to have callchains when %bp based unwinding is not possible, from Jiri Olsa. * Symbol resolution fixes, while fixing support PPC64 files with an .opt ELF section was the end goal, several fixes for code that handles all architectures and cleanups are included, from Cody Schafer. * Add a description for the JIT interface, from Andi Kleen. * Assorted fixes for Documentation and build in 32 bit, from Robert Richter * Add support for non-tracepoint events in perf script python, from Feng Tang * Cache the libtraceevent event_format associated to each evsel early, so that we avoid relookups, i.e. calling pevent_find_event repeatedly when processing tracepoint events. [ This is to reduce the surface contact with libtraceevents and make clear what is that the perf tools needs from that lib: so far parsing the common and per event fields. ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/pwm/pwm-vt8500.c')
-rw-r--r--drivers/pwm/pwm-vt8500.c177
1 files changed, 177 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-vt8500.c b/drivers/pwm/pwm-vt8500.c
new file mode 100644
index 00000000000..548021439f0
--- /dev/null
+++ b/drivers/pwm/pwm-vt8500.c
@@ -0,0 +1,177 @@
+/*
+ * drivers/pwm/pwm-vt8500.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
+
+struct vt8500_chip {
+ struct pwm_chip chip;
+ void __iomem *base;
+};
+
+#define to_vt8500_chip(chip) container_of(chip, struct vt8500_chip, chip)
+
+#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);
+}
+
+static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ int duty_ns, int period_ns)
+{
+ struct vt8500_chip *vt8500 = to_vt8500_chip(chip);
+ unsigned long long c;
+ unsigned long period_cycles, prescale, pv, dc;
+
+ 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(vt8500->base + 0x40 + pwm->hwpwm, (1 << 1));
+ writel(prescale, vt8500->base + 0x4 + (pwm->hwpwm << 4));
+
+ pwm_busy_wait(vt8500->base + 0x40 + pwm->hwpwm, (1 << 2));
+ writel(pv, vt8500->base + 0x8 + (pwm->hwpwm << 4));
+
+ pwm_busy_wait(vt8500->base + 0x40 + pwm->hwpwm, (1 << 3));
+ writel(dc, vt8500->base + 0xc + (pwm->hwpwm << 4));
+
+ return 0;
+}
+
+static int vt8500_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct vt8500_chip *vt8500 = to_vt8500_chip(chip);
+
+ pwm_busy_wait(vt8500->base + 0x40 + pwm->hwpwm, (1 << 0));
+ writel(5, vt8500->base + (pwm->hwpwm << 4));
+ return 0;
+}
+
+static void vt8500_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct vt8500_chip *vt8500 = to_vt8500_chip(chip);
+
+ pwm_busy_wait(vt8500->base + 0x40 + pwm->hwpwm, (1 << 0));
+ writel(0, vt8500->base + (pwm->hwpwm << 4));
+}
+
+static struct pwm_ops vt8500_pwm_ops = {
+ .enable = vt8500_pwm_enable,
+ .disable = vt8500_pwm_disable,
+ .config = vt8500_pwm_config,
+ .owner = THIS_MODULE,
+};
+
+static int __devinit pwm_probe(struct platform_device *pdev)
+{
+ struct vt8500_chip *chip;
+ struct resource *r;
+ int ret;
+
+ chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
+ if (chip == NULL) {
+ dev_err(&pdev->dev, "failed to allocate memory\n");
+ return -ENOMEM;
+ }
+
+ chip->chip.dev = &pdev->dev;
+ chip->chip.ops = &vt8500_pwm_ops;
+ chip->chip.base = -1;
+ chip->chip.npwm = VT8500_NR_PWMS;
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (r == NULL) {
+ dev_err(&pdev->dev, "no memory resource defined\n");
+ return -ENODEV;
+ }
+
+ chip->base = devm_request_and_ioremap(&pdev->dev, r);
+ if (chip->base == NULL)
+ return -EADDRNOTAVAIL;
+
+ ret = pwmchip_add(&chip->chip);
+ if (ret < 0)
+ return ret;
+
+ platform_set_drvdata(pdev, chip);
+ return ret;
+}
+
+static int __devexit pwm_remove(struct platform_device *pdev)
+{
+ struct vt8500_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 = "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");