+/*
+ * Custom GPIO-based PWM driver
+ *
+ * Based on w1-gpio-custom by Copyright (C) 2007 Gabor Juhos <juhosg at openwrt.org>
+ * Copyright (C) 2010 Claudio Mignanti <c.mignanti@gmail.com >
+ *
+ * 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.
+ *
+ * ---------------------------------------------------------------------------
+ *
+ * The behaviour of this driver can be altered by setting some parameters
+ * from the insmod command line.
+ *
+ * The following parameters are adjustable:
+ *
+ * bus0 These four arguments must be arrays
+ * bus1
+ * .....
+ * bus10 <id>,<pin>,<od>
+ *
+ * where:
+ *
+ * <id> ID to used as device_id for the corresponding bus (required)
+ * <pin> GPIO pin ID for PWM channel (required)
+ * *
+ * If this driver is built into the kernel, you can use the following kernel
+ * command line parameters, with the same values as the corresponding module
+ * parameters listed above:
+ *
+ * pwm-gpio-custom.bus0
+ * pwm-gpio-custom.bus1
+ * pwm-gpio-custom.bunN
+ * pwm-gpio-custom.bus10
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+
+#include <linux/pwm/pwm.h>
+
+#define DRV_NAME "pwm-gpio-custom"
+#define DRV_DESC "Custom GPIO-based pwm driver"
+#define DRV_VERSION "0.1.0"
+
+#define PFX DRV_NAME ": "
+
+#define BUS_PARAM_ID 0
+#define BUS_PARAM_PIN 1
+
+#define BUS_PARAM_REQUIRED 2
+#define BUS_PARAM_COUNT 2
+#define BUS_COUNT_MAX 10
+
+static unsigned int bus0[BUS_PARAM_COUNT] __initdata;
+static unsigned int bus1[BUS_PARAM_COUNT] __initdata;
+static unsigned int bus2[BUS_PARAM_COUNT] __initdata;
+static unsigned int bus3[BUS_PARAM_COUNT] __initdata;
+static unsigned int bus4[BUS_PARAM_COUNT] __initdata;
+static unsigned int bus5[BUS_PARAM_COUNT] __initdata;
+static unsigned int bus6[BUS_PARAM_COUNT] __initdata;
+static unsigned int bus7[BUS_PARAM_COUNT] __initdata;
+static unsigned int bus8[BUS_PARAM_COUNT] __initdata;
+static unsigned int bus9[BUS_PARAM_COUNT] __initdata;
+
+static unsigned int bus_nump[BUS_COUNT_MAX] __initdata;
+
+#define BUS_PARM_DESC " config -> id,pin"
+
+module_param_array(bus0, uint, &bus_nump[0], 0);
+MODULE_PARM_DESC(bus0, "bus0" BUS_PARM_DESC);
+module_param_array(bus1, uint, &bus_nump[1], 0);
+MODULE_PARM_DESC(bus1, "bus1" BUS_PARM_DESC);
+module_param_array(bus2, uint, &bus_nump[2], 0);
+MODULE_PARM_DESC(bus2, "bus2" BUS_PARM_DESC);
+module_param_array(bus3, uint, &bus_nump[3], 0);
+MODULE_PARM_DESC(bus3, "bus3" BUS_PARM_DESC);
+module_param_array(bus4, uint, &bus_nump[4], 0);
+MODULE_PARM_DESC(bus4, "bus4" BUS_PARM_DESC);
+module_param_array(bus5, uint, &bus_nump[5], 0);
+MODULE_PARM_DESC(bus5, "bus5" BUS_PARM_DESC);
+module_param_array(bus6, uint, &bus_nump[6], 0);
+MODULE_PARM_DESC(bus6, "bus6" BUS_PARM_DESC);
+module_param_array(bus7, uint, &bus_nump[7], 0);
+MODULE_PARM_DESC(bus7, "bus7" BUS_PARM_DESC);
+module_param_array(bus8, uint, &bus_nump[8], 0);
+MODULE_PARM_DESC(bus8, "bus8" BUS_PARM_DESC);
+module_param_array(bus9, uint, &bus_nump[9], 0);
+MODULE_PARM_DESC(bus9, "bus9" BUS_PARM_DESC);
+
+static struct platform_device *devices[BUS_COUNT_MAX];
+static unsigned int nr_devices;
+
+static void pwm_gpio_custom_cleanup(void)
+{
+ int i;
+
+ for (i = 0; i < nr_devices; i++)
+ if (devices[i])
+ platform_device_put(devices[i]);
+}
+
+static int __init pwm_gpio_custom_add_one(unsigned int id, unsigned int *params)
+{
+ struct platform_device *pdev;
+ struct gpio_pwm_platform_data pdata;
+ int err;
+
+ if (!bus_nump[id])
+ return 0;
+
+ if (bus_nump[id] < BUS_PARAM_REQUIRED) {
+ printk(KERN_ERR PFX "not enough parameters for bus%d\n", id);
+ err = -EINVAL;
+ goto err;
+ }
+
+ pdev = platform_device_alloc("gpio_pwm", params[BUS_PARAM_ID]);
+ if (!pdev) {
+ err = -ENOMEM;
+ goto err;
+ }
+
+ pdata.gpio = params[BUS_PARAM_PIN];
+
+ err = platform_device_add_data(pdev, &pdata, sizeof(pdata));
+ if (err)
+ goto err_put;
+
+ err = platform_device_add(pdev);
+ if (err)
+ goto err_put;
+
+ devices[nr_devices++] = pdev;
+ return 0;
+
+ err_put:
+ platform_device_put(pdev);
+ err:
+ return err;
+}
+
+static int __init pwm_gpio_custom_probe(void)
+{
+ int err;
+
+ nr_devices = 0;
+ printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n");
+
+ err = pwm_gpio_custom_add_one(0, bus0);
+ if (err) goto err;
+
+ err = pwm_gpio_custom_add_one(1, bus1);
+ if (err) goto err;
+
+ err = pwm_gpio_custom_add_one(2, bus2);
+ if (err) goto err;
+
+ err = pwm_gpio_custom_add_one(3, bus3);
+ if (err) goto err;
+
+ err = pwm_gpio_custom_add_one(4, bus4);
+ if (err) goto err;
+
+ err = pwm_gpio_custom_add_one(5, bus5);
+ if (err) goto err;
+
+ err = pwm_gpio_custom_add_one(6, bus6);
+ if (err) goto err;
+
+ err = pwm_gpio_custom_add_one(7, bus7);
+ if (err) goto err;
+
+ err = pwm_gpio_custom_add_one(8, bus8);
+ if (err) goto err;
+
+ err = pwm_gpio_custom_add_one(9, bus9);
+ if (err) goto err;
+
+ if (!nr_devices) {
+ printk(KERN_ERR PFX "no bus parameter(s) specified\n");
+ err = -ENODEV;
+ goto err;
+ }
+
+ return 0;
+
+err:
+ pwm_gpio_custom_cleanup();
+ return err;
+}
+
+#ifdef MODULE
+static int __init pwm_gpio_custom_init(void)
+{
+ return pwm_gpio_custom_probe();
+}
+module_init(pwm_gpio_custom_init);
+
+static void __exit pwm_gpio_custom_exit(void)
+{
+ pwm_gpio_custom_cleanup();
+}
+module_exit(pwm_gpio_custom_exit);
+#else
+subsys_initcall(pwm_gpio_custom_probe);
+#endif /* MODULE*/
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Bifferos <bifferos at yahoo.co.uk >");
+MODULE_AUTHOR("Claudio Mignanti <c.mignanti@gmail.com >");
+MODULE_DESCRIPTION(DRV_DESC);
+MODULE_VERSION(DRV_VERSION);
+