diff options
author | Ingo Molnar <mingo@kernel.org> | 2012-08-21 11:27:00 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2012-08-21 11:27:00 +0200 |
commit | bcada3d4b8c96b8792c2306f363992ca5ab9da42 (patch) | |
tree | e420679a5db6ea4e1694eef57f9abb6acac8d4d3 /drivers/pwm/pwm-pxa.c | |
parent | 26198c21d1b286a084fe5d514a30bc7e6c712a34 (diff) | |
parent | 000078bc3ee69efb1124b8478c7527389a826074 (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-pxa.c')
-rw-r--r-- | drivers/pwm/pwm-pxa.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-pxa.c b/drivers/pwm/pwm-pxa.c new file mode 100644 index 00000000000..bd5867a1c70 --- /dev/null +++ b/drivers/pwm/pwm-pxa.c @@ -0,0 +1,218 @@ +/* + * 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 <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"); |