/*
   * Windfarm PowerMac thermal control. SMU based controls
   *
   * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
   *                    <benh@kernel.crashing.org>
   *
   * Released under the term of the GNU GPL v2.
   */
  
  #include <linux/types.h>
  #include <linux/errno.h>
  #include <linux/kernel.h>
  #include <linux/delay.h>
  #include <linux/slab.h>
  #include <linux/init.h>
  #include <linux/wait.h>
  #include <linux/completion.h>
  #include <asm/prom.h>
  #include <asm/machdep.h>
  #include <asm/io.h>
  #include <asm/sections.h>
  #include <asm/smu.h>
  
  #include "windfarm.h"
  
  #define VERSION "0.4"
  
  #undef DEBUG
  
  #ifdef DEBUG
  #define DBG(args...)	printk(args)
  #else
  #define DBG(args...)	do { } while(0)
  #endif
  
  static int smu_supports_new_fans_ops = 1;
  
  /*
   * SMU fans control object
   */
  
  static LIST_HEAD(smu_fans);
  
  struct smu_fan_control {
  	struct list_head	link;
  	int    			fan_type;	/* 0 = rpm, 1 = pwm */
  	u32			reg;		/* index in SMU */
  	s32			value;		/* current value */
  	s32			min, max;	/* min/max values */
  	struct wf_control	ctrl;
  };
  #define to_smu_fan(c) container_of(c, struct smu_fan_control, ctrl)
  
  static int smu_set_fan(int pwm, u8 id, u16 value)
  {
  	struct smu_cmd cmd;
  	u8 buffer[16];
  	DECLARE_COMPLETION_ONSTACK(comp);
  	int rc;
  
  	/* Fill SMU command structure */
  	cmd.cmd = SMU_CMD_FAN_COMMAND;
  
  	/* The SMU has an "old" and a "new" way of setting the fan speed
  	 * Unfortunately, I found no reliable way to know which one works
  	 * on a given machine model. After some investigations it appears
  	 * that MacOS X just tries the new one, and if it fails fallbacks
  	 * to the old ones ... Ugh.
  	 */
   retry:
  	if (smu_supports_new_fans_ops) {
  		buffer[0] = 0x30;
  		buffer[1] = id;
  		*((u16 *)(&buffer[2])) = value;
  		cmd.data_len = 4;
  	} else {
  		if (id > 7)
  			return -EINVAL;
  		/* Fill argument buffer */
  		memset(buffer, 0, 16);
  		buffer[0] = pwm ? 0x10 : 0x00;
  		buffer[1] = 0x01 << id;
  		*((u16 *)&buffer[2 + id * 2]) = value;
  		cmd.data_len = 14;
  	}
  
  	cmd.reply_len = 16;
  	cmd.data_buf = cmd.reply_buf = buffer;
  	cmd.status = 0;
  	cmd.done = smu_done_complete;
  	cmd.misc = &comp;
  
  	rc = smu_queue_cmd(&cmd);
  	if (rc)
  		return rc;
  	wait_for_completion(&comp);
  
  	/* Handle fallback (see coment above) */
  	if (cmd.status != 0 && smu_supports_new_fans_ops) {
  		printk(KERN_WARNING "windfarm: SMU failed new fan command "
  		       "falling back to old method
  ");
  		smu_supports_new_fans_ops = 0;
  		goto retry;
  	}
  
  	return cmd.status;
  }
  
  static void smu_fan_release(struct wf_control *ct)
  {
  	struct smu_fan_control *fct = to_smu_fan(ct);
  
  	kfree(fct);
  }
  
  static int smu_fan_set(struct wf_control *ct, s32 value)
  {
  	struct smu_fan_control *fct = to_smu_fan(ct);
  
  	if (value < fct->min)
  		value = fct->min;
  	if (value > fct->max)
  		value = fct->max;
  	fct->value = value;
  
  	return smu_set_fan(fct->fan_type, fct->reg, value);
  }
  
  static int smu_fan_get(struct wf_control *ct, s32 *value)
  {
  	struct smu_fan_control *fct = to_smu_fan(ct);
  	*value = fct->value; /* todo: read from SMU */
  	return 0;
  }
  
  static s32 smu_fan_min(struct wf_control *ct)
  {
  	struct smu_fan_control *fct = to_smu_fan(ct);
  	return fct->min;
  }
  
  static s32 smu_fan_max(struct wf_control *ct)
  {
  	struct smu_fan_control *fct = to_smu_fan(ct);
  	return fct->max;
  }
  
  static struct wf_control_ops smu_fan_ops = {
  	.set_value	= smu_fan_set,
  	.get_value	= smu_fan_get,
  	.get_min	= smu_fan_min,
  	.get_max	= smu_fan_max,
  	.release	= smu_fan_release,
  	.owner		= THIS_MODULE,
  };
  
  static struct smu_fan_control *smu_fan_create(struct device_node *node,
  					      int pwm_fan)
  {
  	struct smu_fan_control *fct;
  	const s32 *v;
  	const u32 *reg;
  	const char *l;
  
  	fct = kmalloc(sizeof(struct smu_fan_control), GFP_KERNEL);
  	if (fct == NULL)
  		return NULL;
  	fct->ctrl.ops = &smu_fan_ops;
  	l = of_get_property(node, "location", NULL);
  	if (l == NULL)
  		goto fail;
  
  	fct->fan_type = pwm_fan;
  	fct->ctrl.type = pwm_fan ? WF_CONTROL_PWM_FAN : WF_CONTROL_RPM_FAN;
  
  	/* We use the name & location here the same way we do for SMU sensors,
  	 * see the comment in windfarm_smu_sensors.c. The locations are a bit
  	 * less consistent here between the iMac and the desktop models, but
  	 * that is good enough for our needs for now at least.
  	 *
  	 * One problem though is that Apple seem to be inconsistent with case
  	 * and the kernel doesn't have strcasecmp =P
  	 */
  
  	fct->ctrl.name = NULL;
  
  	/* Names used on desktop models */
  	if (!strcmp(l, "Rear Fan 0") || !strcmp(l, "Rear Fan") ||
  	    !strcmp(l, "Rear fan 0") || !strcmp(l, "Rear fan") ||
  	    !strcmp(l, "CPU A EXHAUST"))
  		fct->ctrl.name = "cpu-rear-fan-0";
  	else if (!strcmp(l, "Rear Fan 1") || !strcmp(l, "Rear fan 1") ||
  		 !strcmp(l, "CPU B EXHAUST"))
  		fct->ctrl.name = "cpu-rear-fan-1";
  	else if (!strcmp(l, "Front Fan 0") || !strcmp(l, "Front Fan") ||
  		 !strcmp(l, "Front fan 0") || !strcmp(l, "Front fan") ||
  		 !strcmp(l, "CPU A INTAKE"))
  		fct->ctrl.name = "cpu-front-fan-0";
  	else if (!strcmp(l, "Front Fan 1") || !strcmp(l, "Front fan 1") ||
  		 !strcmp(l, "CPU B INTAKE"))
  		fct->ctrl.name = "cpu-front-fan-1";
  	else if (!strcmp(l, "CPU A PUMP"))
  		fct->ctrl.name = "cpu-pump-0";
  	else if (!strcmp(l, "CPU B PUMP"))
  		fct->ctrl.name = "cpu-pump-1";
  	else if (!strcmp(l, "Slots Fan") || !strcmp(l, "Slots fan") ||
  		 !strcmp(l, "EXPANSION SLOTS INTAKE"))
  		fct->ctrl.name = "slots-fan";
  	else if (!strcmp(l, "Drive Bay") || !strcmp(l, "Drive bay") ||
  		 !strcmp(l, "DRIVE BAY A INTAKE"))
  		fct->ctrl.name = "drive-bay-fan";
  	else if (!strcmp(l, "BACKSIDE"))
  		fct->ctrl.name = "backside-fan";
  
  	/* Names used on iMac models */
  	if (!strcmp(l, "System Fan") || !strcmp(l, "System fan"))
  		fct->ctrl.name = "system-fan";
  	else if (!strcmp(l, "CPU Fan") || !strcmp(l, "CPU fan"))
  		fct->ctrl.name = "cpu-fan";
  	else if (!strcmp(l, "Hard Drive") || !strcmp(l, "Hard drive"))
  		fct->ctrl.name = "drive-bay-fan";
  	else if (!strcmp(l, "HDD Fan")) /* seen on iMac G5 iSight */
  		fct->ctrl.name = "hard-drive-fan";
  	else if (!strcmp(l, "ODD Fan")) /* same */
  		fct->ctrl.name = "optical-drive-fan";
  
  	/* Unrecognized fan, bail out */
  	if (fct->ctrl.name == NULL)
  		goto fail;
  
  	/* Get min & max values*/
  	v = of_get_property(node, "min-value", NULL);
  	if (v == NULL)
  		goto fail;
  	fct->min = *v;
  	v = of_get_property(node, "max-value", NULL);
  	if (v == NULL)
  		goto fail;
  	fct->max = *v;
  
  	/* Get "reg" value */
  	reg = of_get_property(node, "reg", NULL);
  	if (reg == NULL)
  		goto fail;
  	fct->reg = *reg;
  
  	if (wf_register_control(&fct->ctrl))
  		goto fail;
  
  	return fct;
   fail:
  	kfree(fct);
  	return NULL;
  }
  
  
  static int __init smu_controls_init(void)
  {
  	struct device_node *smu, *fans, *fan;
  
  	if (!smu_present())
  		return -ENODEV;
  
  	smu = of_find_node_by_type(NULL, "smu");
  	if (smu == NULL)
  		return -ENODEV;
  
  	/* Look for RPM fans */
  	for (fans = NULL; (fans = of_get_next_child(smu, fans)) != NULL;)
  		if (!strcmp(fans->name, "rpm-fans") ||
  		    of_device_is_compatible(fans, "smu-rpm-fans"))
  			break;
  	for (fan = NULL;
  	     fans && (fan = of_get_next_child(fans, fan)) != NULL;) {
  		struct smu_fan_control *fct;
  
  		fct = smu_fan_create(fan, 0);
  		if (fct == NULL) {
  			printk(KERN_WARNING "windfarm: Failed to create SMU "
  			       "RPM fan %s
  ", fan->name);
  			continue;
  		}
  		list_add(&fct->link, &smu_fans);
  	}
  	of_node_put(fans);
  
  
  	/* Look for PWM fans */
  	for (fans = NULL; (fans = of_get_next_child(smu, fans)) != NULL;)
  		if (!strcmp(fans->name, "pwm-fans"))
  			break;
  	for (fan = NULL;
  	     fans && (fan = of_get_next_child(fans, fan)) != NULL;) {
  		struct smu_fan_control *fct;
  
  		fct = smu_fan_create(fan, 1);
  		if (fct == NULL) {
  			printk(KERN_WARNING "windfarm: Failed to create SMU "
  			       "PWM fan %s
  ", fan->name);
  			continue;
  		}
  		list_add(&fct->link, &smu_fans);
  	}
  	of_node_put(fans);
  	of_node_put(smu);
  
  	return 0;
  }
  
  static void __exit smu_controls_exit(void)
  {
  	struct smu_fan_control *fct;
  
  	while (!list_empty(&smu_fans)) {
  		fct = list_entry(smu_fans.next, struct smu_fan_control, link);
  		list_del(&fct->link);
  		wf_unregister_control(&fct->ctrl);
  	}
  }
  
  
  module_init(smu_controls_init);
  module_exit(smu_controls_exit);
  
  MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
  MODULE_DESCRIPTION("SMU control objects for PowerMacs thermal control");
  MODULE_LICENSE("GPL");