[PATCH v4 09/10] pwm: Add PXA support
Thierry Reding
thierry.reding at avionic-design.de
Wed Mar 14 11:56:32 EDT 2012
Signed-off-by: Thierry Reding <thierry.reding at avionic-design.de>
---
Changes in v3:
- update PWM ops for changes in patch 2
arch/arm/plat-pxa/Makefile | 1 -
arch/arm/plat-pxa/pwm.c | 304 --------------------------------------------
drivers/pwm/Kconfig | 9 ++
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-pxa.c | 244 +++++++++++++++++++++++++++++++++++
5 files changed, 254 insertions(+), 305 deletions(-)
delete mode 100644 arch/arm/plat-pxa/pwm.c
create mode 100644 drivers/pwm/pwm-pxa.c
diff --git a/arch/arm/plat-pxa/Makefile b/arch/arm/plat-pxa/Makefile
index f302d04..af8e484 100644
--- a/arch/arm/plat-pxa/Makefile
+++ b/arch/arm/plat-pxa/Makefile
@@ -8,5 +8,4 @@ obj-$(CONFIG_PXA3xx) += mfp.o
obj-$(CONFIG_PXA95x) += mfp.o
obj-$(CONFIG_ARCH_MMP) += mfp.o
-obj-$(CONFIG_HAVE_PWM) += pwm.o
obj-$(CONFIG_PXA_SSP) += ssp.o
diff --git a/arch/arm/plat-pxa/pwm.c b/arch/arm/plat-pxa/pwm.c
deleted file mode 100644
index ef32686..0000000
--- a/arch/arm/plat-pxa/pwm.c
+++ /dev/null
@@ -1,304 +0,0 @@
-/*
- * linux/arch/arm/mach-pxa/pwm.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 at 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 pwm_device {
- struct list_head node;
- struct pwm_device *secondary;
- struct platform_device *pdev;
-
- const char *label;
- struct clk *clk;
- int clk_enabled;
- void __iomem *mmio_base;
-
- unsigned int use_count;
- unsigned int pwm_id;
-};
-
-/*
- * period_ns = 10^9 * (PRESCALE + 1) * (PV + 1) / PWM_CLK_RATE
- * duty_ns = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE
- */
-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 = clk_get_rate(pwm->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
- */
- clk_enable(pwm->clk);
- __raw_writel(prescale, pwm->mmio_base + PWMCR);
- __raw_writel(dc, pwm->mmio_base + PWMDCR);
- __raw_writel(pv, pwm->mmio_base + PWMPCR);
- clk_disable(pwm->clk);
-
- return 0;
-}
-EXPORT_SYMBOL(pwm_config);
-
-int pwm_enable(struct pwm_device *pwm)
-{
- int rc = 0;
-
- if (!pwm->clk_enabled) {
- rc = clk_enable(pwm->clk);
- if (!rc)
- pwm->clk_enabled = 1;
- }
- return rc;
-}
-EXPORT_SYMBOL(pwm_enable);
-
-void pwm_disable(struct pwm_device *pwm)
-{
- if (pwm->clk_enabled) {
- clk_disable(pwm->clk);
- pwm->clk_enabled = 0;
- }
-}
-EXPORT_SYMBOL(pwm_disable);
-
-static DEFINE_MUTEX(pwm_lock);
-static LIST_HEAD(pwm_list);
-
-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)
-{
- const struct platform_device_id *id = platform_get_device_id(pdev);
- struct pwm_device *pwm, *secondary = NULL;
- struct resource *r;
- int ret = 0;
-
- pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
- if (pwm == NULL) {
- dev_err(&pdev->dev, "failed to allocate memory\n");
- return -ENOMEM;
- }
-
- pwm->clk = clk_get(&pdev->dev, NULL);
- if (IS_ERR(pwm->clk)) {
- ret = PTR_ERR(pwm->clk);
- goto err_free;
- }
- pwm->clk_enabled = 0;
-
- pwm->use_count = 0;
- pwm->pwm_id = PWM_ID_BASE(id->driver_data) + pdev->id;
- pwm->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_clk;
- }
-
- 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_clk;
- }
-
- pwm->mmio_base = ioremap(r->start, resource_size(r));
- if (pwm->mmio_base == NULL) {
- dev_err(&pdev->dev, "failed to ioremap() registers\n");
- ret = -ENODEV;
- goto err_free_mem;
- }
-
- if (id->driver_data & HAS_SECONDARY_PWM) {
- secondary = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
- if (secondary == NULL) {
- ret = -ENOMEM;
- goto err_free_mem;
- }
-
- *secondary = *pwm;
- pwm->secondary = secondary;
-
- /* registers for the second PWM has offset of 0x10 */
- secondary->mmio_base = pwm->mmio_base + 0x10;
- secondary->pwm_id = pdev->id + 2;
- }
-
- __add_pwm(pwm);
- if (secondary)
- __add_pwm(secondary);
-
- platform_set_drvdata(pdev, pwm);
- return 0;
-
-err_free_mem:
- release_mem_region(r->start, resource_size(r));
-err_free_clk:
- clk_put(pwm->clk);
-err_free:
- kfree(pwm);
- return ret;
-}
-
-static int __devexit pwm_remove(struct platform_device *pdev)
-{
- struct pwm_device *pwm;
- struct resource *r;
-
- pwm = platform_get_drvdata(pdev);
- if (pwm == NULL)
- return -ENODEV;
-
- mutex_lock(&pwm_lock);
-
- if (pwm->secondary) {
- list_del(&pwm->secondary->node);
- kfree(pwm->secondary);
- }
-
- list_del(&pwm->node);
- mutex_unlock(&pwm_lock);
-
- iounmap(pwm->mmio_base);
-
- r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- release_mem_region(r->start, resource_size(r));
-
- clk_put(pwm->clk);
- kfree(pwm);
- return 0;
-}
-
-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");
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index eb54042..0ef4f30 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -18,6 +18,15 @@ config PWM_BFIN
To compile this driver as a module, choose M here: the module
will be called pwm-bfin.
+config PWM_PXA
+ tristate "PXA PWM support"
+ depends on ARCH_PXA
+ help
+ Generic PWM framework driver for PXA.
+
+ To compile this driver as a module, choose M here: the module
+ will be called pwm-pxa.
+
config PWM_TEGRA
tristate "NVIDIA Tegra PWM support"
depends on ARCH_TEGRA
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index 251b8d2..e859c51 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -1,3 +1,4 @@
obj-$(CONFIG_PWM) += core.o
obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o
+obj-$(CONFIG_PWM_PXA) += pwm-pxa.o
obj-$(CONFIG_PWM_TEGRA) += pwm-tegra.o
diff --git a/drivers/pwm/pwm-pxa.c b/drivers/pwm/pwm-pxa.c
new file mode 100644
index 0000000..0f3ef5c
--- /dev/null
+++ b/drivers/pwm/pwm-pxa.c
@@ -0,0 +1,244 @@
+/*
+ * linux/arch/arm/mach-pxa/pwm.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 at 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;
+
+ 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
+ */
+ clk_enable(pc->clk);
+ __raw_writel(prescale, pc->mmio_base + offset + PWMCR);
+ __raw_writel(dc, pc->mmio_base + offset + PWMDCR);
+ __raw_writel(pv, pc->mmio_base + offset + PWMPCR);
+ clk_disable(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_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(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 = kzalloc(sizeof(*pwm), GFP_KERNEL);
+ if (pwm == NULL) {
+ dev_err(&pdev->dev, "failed to allocate memory\n");
+ return -ENOMEM;
+ }
+
+ pwm->clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(pwm->clk)) {
+ ret = PTR_ERR(pwm->clk);
+ goto err_free;
+ }
+ 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");
+ ret = -ENODEV;
+ goto err_free_clk;
+ }
+
+ 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_clk;
+ }
+
+ pwm->mmio_base = ioremap(r->start, resource_size(r));
+ if (pwm->mmio_base == NULL) {
+ dev_err(&pdev->dev, "failed to ioremap() registers\n");
+ ret = -ENODEV;
+ goto err_free_mem;
+ }
+
+ 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;
+
+err_free_mem:
+ release_mem_region(r->start, resource_size(r));
+err_free_clk:
+ clk_put(pwm->clk);
+err_free:
+ kfree(pwm);
+ return ret;
+}
+
+static int __devexit pwm_remove(struct platform_device *pdev)
+{
+ struct pxa_pwm_chip *chip;
+ struct resource *r;
+
+ chip = platform_get_drvdata(pdev);
+ if (chip == NULL)
+ return -ENODEV;
+
+ pwmchip_remove(&chip->chip);
+
+ iounmap(chip->mmio_base);
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ release_mem_region(r->start, resource_size(r));
+
+ clk_put(chip->clk);
+ kfree(chip);
+ return 0;
+}
+
+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");
--
1.7.9.4
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