]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/commitdiff
ARM i.MX: Move i.MX pwm driver to pwm framework
authorSascha Hauer <s.hauer@pengutronix.de>
Thu, 15 Mar 2012 09:04:35 +0000 (10:04 +0100)
committerThierry Reding <thierry.reding@avionic-design.de>
Mon, 2 Jul 2012 19:39:01 +0000 (21:39 +0200)
Move the driver to drivers/pwm/ and convert it to use the framework.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
[eric@eukrea.com: set chip.dev to prevent probe failure]
[eric@eukrea.com: fix pwmchip_add return code test]
Signed-off-by: Eric BĂ©nard <eric@eukrea.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
arch/arm/plat-mxc/Kconfig
arch/arm/plat-mxc/Makefile
arch/arm/plat-mxc/pwm.c [deleted file]
drivers/pwm/Kconfig
drivers/pwm/Makefile
drivers/pwm/pwm-imx.c [new file with mode: 0644]

index c722f9ce691827e8924674119b75708ba7ea6428..baf9064c0844bcafef399f943209a570dc34ceec 100644 (file)
@@ -47,12 +47,6 @@ config MXC_TZIC
 config MXC_AVIC
        bool
 
-config MXC_PWM
-       tristate "Enable PWM driver"
-       select HAVE_PWM
-       help
-         Enable support for the i.MX PWM controller(s).
-
 config MXC_DEBUG_BOARD
        bool "Enable MXC debug board(for 3-stack)"
        help
index e81290c27c655bdf4ab5f4d58a61ee41cc8013e9..46ba8de2fe4ee2c2c7820552c4eab05cb1021431 100644 (file)
@@ -11,7 +11,6 @@ obj-$(CONFIG_MXC_AVIC) += avic.o
 obj-$(CONFIG_IMX_HAVE_IOMUX_V1) += iomux-v1.o
 obj-$(CONFIG_ARCH_MXC_IOMUX_V3) += iomux-v3.o
 obj-$(CONFIG_IRAM_ALLOC) += iram_alloc.o
-obj-$(CONFIG_MXC_PWM)  += pwm.o
 obj-$(CONFIG_MXC_ULPI) += ulpi.o
 obj-$(CONFIG_MXC_USE_EPIT) += epit.o
 obj-$(CONFIG_MXC_DEBUG_BOARD) += 3ds_debugboard.o
diff --git a/arch/arm/plat-mxc/pwm.c b/arch/arm/plat-mxc/pwm.c
deleted file mode 100644 (file)
index c0cab22..0000000
+++ /dev/null
@@ -1,306 +0,0 @@
-/*
- * 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.
- *
- * Derived from pxa PWM driver by 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 <mach/hardware.h>
-
-
-/* i.MX1 and i.MX21 share the same PWM function block: */
-
-#define MX1_PWMC    0x00   /* PWM Control Register */
-#define MX1_PWMS    0x04   /* PWM Sample Register */
-#define MX1_PWMP    0x08   /* PWM Period Register */
-
-
-/* i.MX27, i.MX31, i.MX35 share the same PWM function block: */
-
-#define MX3_PWMCR                 0x00    /* PWM Control Register */
-#define MX3_PWMSAR                0x0C    /* PWM Sample Register */
-#define MX3_PWMPR                 0x10    /* PWM Period Register */
-#define MX3_PWMCR_PRESCALER(x)    (((x - 1) & 0xFFF) << 4)
-#define MX3_PWMCR_DOZEEN                (1 << 24)
-#define MX3_PWMCR_WAITEN                (1 << 23)
-#define MX3_PWMCR_DBGEN                        (1 << 22)
-#define MX3_PWMCR_CLKSRC_IPG_HIGH (2 << 16)
-#define MX3_PWMCR_CLKSRC_IPG      (1 << 16)
-#define MX3_PWMCR_EN              (1 << 0)
-
-
-
-struct pwm_device {
-       struct list_head        node;
-       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;
-};
-
-int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
-{
-       if (pwm == NULL || period_ns == 0 || duty_ns > period_ns)
-               return -EINVAL;
-
-       if (!(cpu_is_mx1() || cpu_is_mx21())) {
-               unsigned long long c;
-               unsigned long period_cycles, duty_cycles, prescale;
-               u32 cr;
-
-               c = clk_get_rate(pwm->clk);
-               c = c * period_ns;
-               do_div(c, 1000000000);
-               period_cycles = c;
-
-               prescale = period_cycles / 0x10000 + 1;
-
-               period_cycles /= prescale;
-               c = (unsigned long long)period_cycles * duty_ns;
-               do_div(c, period_ns);
-               duty_cycles = c;
-
-               /*
-                * according to imx pwm RM, the real period value should be
-                * PERIOD value in PWMPR plus 2.
-                */
-               if (period_cycles > 2)
-                       period_cycles -= 2;
-               else
-                       period_cycles = 0;
-
-               writel(duty_cycles, pwm->mmio_base + MX3_PWMSAR);
-               writel(period_cycles, pwm->mmio_base + MX3_PWMPR);
-
-               cr = MX3_PWMCR_PRESCALER(prescale) |
-                       MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
-                       MX3_PWMCR_DBGEN | MX3_PWMCR_EN;
-
-               if (cpu_is_mx25())
-                       cr |= MX3_PWMCR_CLKSRC_IPG;
-               else
-                       cr |= MX3_PWMCR_CLKSRC_IPG_HIGH;
-
-               writel(cr, pwm->mmio_base + MX3_PWMCR);
-       } else if (cpu_is_mx1() || cpu_is_mx21()) {
-               /* The PWM subsystem allows for exact frequencies. However,
-                * I cannot connect a scope on my device to the PWM line and
-                * thus cannot provide the program the PWM controller
-                * exactly. Instead, I'm relying on the fact that the
-                * Bootloader (u-boot or WinCE+haret) has programmed the PWM
-                * function group already. So I'll just modify the PWM sample
-                * register to follow the ratio of duty_ns vs. period_ns
-                * accordingly.
-                *
-                * This is good enough for programming the brightness of
-                * the LCD backlight.
-                *
-                * The real implementation would divide PERCLK[0] first by
-                * both the prescaler (/1 .. /128) and then by CLKSEL
-                * (/2 .. /16).
-                */
-               u32 max = readl(pwm->mmio_base + MX1_PWMP);
-               u32 p = max * duty_ns / period_ns;
-               writel(max - p, pwm->mmio_base + MX1_PWMS);
-       } else {
-               BUG();
-       }
-
-       return 0;
-}
-EXPORT_SYMBOL(pwm_config);
-
-int pwm_enable(struct pwm_device *pwm)
-{
-       int rc = 0;
-
-       if (!pwm->clk_enabled) {
-               rc = clk_prepare_enable(pwm->clk);
-               if (!rc)
-                       pwm->clk_enabled = 1;
-       }
-       return rc;
-}
-EXPORT_SYMBOL(pwm_enable);
-
-void pwm_disable(struct pwm_device *pwm)
-{
-       writel(0, pwm->mmio_base + MX3_PWMCR);
-
-       if (pwm->clk_enabled) {
-               clk_disable_unprepare(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 int __devinit mxc_pwm_probe(struct platform_device *pdev)
-{
-       struct pwm_device *pwm;
-       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, "pwm");
-
-       if (IS_ERR(pwm->clk)) {
-               ret = PTR_ERR(pwm->clk);
-               goto err_free;
-       }
-
-       pwm->clk_enabled = 0;
-
-       pwm->use_count = 0;
-       pwm->pwm_id = 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;
-       }
-
-       mutex_lock(&pwm_lock);
-       list_add_tail(&pwm->node, &pwm_list);
-       mutex_unlock(&pwm_lock);
-
-       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 mxc_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);
-       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 mxc_pwm_driver = {
-       .driver         = {
-               .name   = "mxc_pwm",
-       },
-       .probe          = mxc_pwm_probe,
-       .remove         = __devexit_p(mxc_pwm_remove),
-};
-
-static int __init mxc_pwm_init(void)
-{
-       return platform_driver_register(&mxc_pwm_driver);
-}
-arch_initcall(mxc_pwm_init);
-
-static void __exit mxc_pwm_exit(void)
-{
-       platform_driver_unregister(&mxc_pwm_driver);
-}
-module_exit(mxc_pwm_exit);
-
-MODULE_LICENSE("GPL v2");
-MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
index 0ef4f3037c4a0be19fb59bda713c87d0b60c14d9..a9a971581108c2d18d489abfa449726e5624587a 100644 (file)
@@ -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_IMX
+       tristate "i.MX pwm support"
+       depends on ARCH_MXC
+       help
+         Generic PWM framework driver for i.MX.
+
+         To compile this driver as a module, choose M here: the module
+         will be called pwm-imx.
+
 config PWM_PXA
        tristate "PXA PWM support"
        depends on ARCH_PXA
index e859c513add8002addc458378c3d5c9d79d69464..3dd1b8357a0cbc50aca650e38b24004eafc5c9be 100644 (file)
@@ -1,4 +1,5 @@
 obj-$(CONFIG_PWM)              += core.o
 obj-$(CONFIG_PWM_BFIN)         += pwm-bfin.o
+obj-$(CONFIG_PWM_IMX)          += pwm-imx.o
 obj-$(CONFIG_PWM_PXA)          += pwm-pxa.o
 obj-$(CONFIG_PWM_TEGRA)                += pwm-tegra.o
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
new file mode 100644 (file)
index 0000000..900d145
--- /dev/null
@@ -0,0 +1,267 @@
+/*
+ * 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.
+ *
+ * Derived from pxa PWM driver by 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 <mach/hardware.h>
+
+
+/* i.MX1 and i.MX21 share the same PWM function block: */
+
+#define MX1_PWMC    0x00   /* PWM Control Register */
+#define MX1_PWMS    0x04   /* PWM Sample Register */
+#define MX1_PWMP    0x08   /* PWM Period Register */
+
+
+/* i.MX27, i.MX31, i.MX35 share the same PWM function block: */
+
+#define MX3_PWMCR                 0x00    /* PWM Control Register */
+#define MX3_PWMSAR                0x0C    /* PWM Sample Register */
+#define MX3_PWMPR                 0x10    /* PWM Period Register */
+#define MX3_PWMCR_PRESCALER(x)    (((x - 1) & 0xFFF) << 4)
+#define MX3_PWMCR_DOZEEN                (1 << 24)
+#define MX3_PWMCR_WAITEN                (1 << 23)
+#define MX3_PWMCR_DBGEN                        (1 << 22)
+#define MX3_PWMCR_CLKSRC_IPG_HIGH (2 << 16)
+#define MX3_PWMCR_CLKSRC_IPG      (1 << 16)
+#define MX3_PWMCR_EN              (1 << 0)
+
+struct imx_chip {
+       struct clk      *clk;
+
+       int             clk_enabled;
+       void __iomem    *mmio_base;
+
+       struct pwm_chip chip;
+};
+
+#define to_imx_chip(chip)      container_of(chip, struct imx_chip, chip)
+
+static int imx_pwm_config(struct pwm_chip *chip,
+               struct pwm_device *pwm, int duty_ns, int period_ns)
+{
+       struct imx_chip *imx = to_imx_chip(chip);
+
+       if (!(cpu_is_mx1() || cpu_is_mx21())) {
+               unsigned long long c;
+               unsigned long period_cycles, duty_cycles, prescale;
+               u32 cr;
+
+               c = clk_get_rate(imx->clk);
+               c = c * period_ns;
+               do_div(c, 1000000000);
+               period_cycles = c;
+
+               prescale = period_cycles / 0x10000 + 1;
+
+               period_cycles /= prescale;
+               c = (unsigned long long)period_cycles * duty_ns;
+               do_div(c, period_ns);
+               duty_cycles = c;
+
+               /*
+                * according to imx pwm RM, the real period value should be
+                * PERIOD value in PWMPR plus 2.
+                */
+               if (period_cycles > 2)
+                       period_cycles -= 2;
+               else
+                       period_cycles = 0;
+
+               writel(duty_cycles, imx->mmio_base + MX3_PWMSAR);
+               writel(period_cycles, imx->mmio_base + MX3_PWMPR);
+
+               cr = MX3_PWMCR_PRESCALER(prescale) |
+                       MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
+                       MX3_PWMCR_DBGEN | MX3_PWMCR_EN;
+
+               if (cpu_is_mx25())
+                       cr |= MX3_PWMCR_CLKSRC_IPG;
+               else
+                       cr |= MX3_PWMCR_CLKSRC_IPG_HIGH;
+
+               writel(cr, imx->mmio_base + MX3_PWMCR);
+       } else if (cpu_is_mx1() || cpu_is_mx21()) {
+               /* The PWM subsystem allows for exact frequencies. However,
+                * I cannot connect a scope on my device to the PWM line and
+                * thus cannot provide the program the PWM controller
+                * exactly. Instead, I'm relying on the fact that the
+                * Bootloader (u-boot or WinCE+haret) has programmed the PWM
+                * function group already. So I'll just modify the PWM sample
+                * register to follow the ratio of duty_ns vs. period_ns
+                * accordingly.
+                *
+                * This is good enough for programming the brightness of
+                * the LCD backlight.
+                *
+                * The real implementation would divide PERCLK[0] first by
+                * both the prescaler (/1 .. /128) and then by CLKSEL
+                * (/2 .. /16).
+                */
+               u32 max = readl(imx->mmio_base + MX1_PWMP);
+               u32 p = max * duty_ns / period_ns;
+               writel(max - p, imx->mmio_base + MX1_PWMS);
+       } else {
+               BUG();
+       }
+
+       return 0;
+}
+
+static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+       struct imx_chip *imx = to_imx_chip(chip);
+       int rc = 0;
+
+       if (!imx->clk_enabled) {
+               rc = clk_prepare_enable(imx->clk);
+               if (!rc)
+                       imx->clk_enabled = 1;
+       }
+       return rc;
+}
+
+static void imx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+       struct imx_chip *imx = to_imx_chip(chip);
+
+       writel(0, imx->mmio_base + MX3_PWMCR);
+
+       if (imx->clk_enabled) {
+               clk_disable_unprepare(imx->clk);
+               imx->clk_enabled = 0;
+       }
+}
+
+static struct pwm_ops imx_pwm_ops = {
+       .enable = imx_pwm_enable,
+       .disable = imx_pwm_disable,
+       .config = imx_pwm_config,
+       .owner = THIS_MODULE,
+};
+
+static int __devinit imx_pwm_probe(struct platform_device *pdev)
+{
+       struct imx_chip *imx;
+       struct resource *r;
+       int ret = 0;
+
+       imx = kzalloc(sizeof(*imx), GFP_KERNEL);
+       if (imx == NULL) {
+               dev_err(&pdev->dev, "failed to allocate memory\n");
+               return -ENOMEM;
+       }
+
+       imx->clk = clk_get(&pdev->dev, "pwm");
+
+       if (IS_ERR(imx->clk)) {
+               ret = PTR_ERR(imx->clk);
+               goto err_free;
+       }
+
+       imx->chip.ops = &imx_pwm_ops;
+       imx->chip.dev = &pdev->dev;
+       imx->chip.base = -1;
+       imx->chip.npwm = 1;
+
+       imx->clk_enabled = 0;
+
+       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;
+       }
+
+       imx->mmio_base = ioremap(r->start, resource_size(r));
+       if (imx->mmio_base == NULL) {
+               dev_err(&pdev->dev, "failed to ioremap() registers\n");
+               ret = -ENODEV;
+               goto err_free_mem;
+       }
+
+       ret = pwmchip_add(&imx->chip);
+       if (ret < 0)
+               goto err_iounmap;
+
+       platform_set_drvdata(pdev, imx);
+       return 0;
+
+err_iounmap:
+       iounmap(imx->mmio_base);
+err_free_mem:
+       release_mem_region(r->start, resource_size(r));
+err_free_clk:
+       clk_put(imx->clk);
+err_free:
+       kfree(imx);
+       return ret;
+}
+
+static int __devexit imx_pwm_remove(struct platform_device *pdev)
+{
+       struct imx_chip *imx;
+       struct resource *r;
+       int ret;
+
+       imx = platform_get_drvdata(pdev);
+       if (imx == NULL)
+               return -ENODEV;
+
+       ret = pwmchip_remove(&imx->chip);
+       if (ret)
+               return ret;
+
+       iounmap(imx->mmio_base);
+
+       r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       release_mem_region(r->start, resource_size(r));
+
+       clk_put(imx->clk);
+
+       kfree(imx);
+       return 0;
+}
+
+static struct platform_driver imx_pwm_driver = {
+       .driver         = {
+               .name   = "mxc_pwm",
+       },
+       .probe          = imx_pwm_probe,
+       .remove         = __devexit_p(imx_pwm_remove),
+};
+
+static int __init imx_pwm_init(void)
+{
+       return platform_driver_register(&imx_pwm_driver);
+}
+arch_initcall(imx_pwm_init);
+
+static void __exit imx_pwm_exit(void)
+{
+       platform_driver_unregister(&imx_pwm_driver);
+}
+module_exit(imx_pwm_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");