EDP: adding power-supply depletion driver

Power-supply depletion driver.

Bug 1274376

Change-Id: I1e18db9bb06a18bb1cc6446fe36ce8422bae67cf
Signed-off-by: Sivaram Nair <sivaramn@nvidia.com>
Reviewed-on: http://git-master/r/226227
GVS: Gerrit_Virtual_Submit
Reviewed-by: Juha Tukkinen <jtukkinen@nvidia.com>

2 files changed, 300 insertions, 0 deletions

diff --git a/drivers/edp/Makefile b/drivers/edp/Makefile
index 2694ad82e2ce..a3799cb07293 100644
--- a/drivers/edp/Makefile
+++ b/drivers/edp/Makefile
@@ -8,4 +8,5 @@ obj-y			+= edp_overage.o
 obj-y			+= edp_priority.o
 obj-y			+= edp_temporal.o
 obj-y			+= edp_sysfs.o
+obj-y			+= psy_depletion.o
 obj-y			+= tegra_core.o
diff --git a/drivers/edp/psy_depletion.c b/drivers/edp/psy_depletion.c
new file mode 100644
index 000000000000..d9eeac5d3fed
--- /dev/null
+++ b/drivers/edp/psy_depletion.c
@@ -0,0 +1,299 @@
+/*
+ * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/edp.h>
+#include <linux/edpdev.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+#define DEPL_INTERVAL	60000
+
+struct depl_driver {
+	struct edp_client client;
+	struct psy_depletion_platform_data *pdata;
+	struct delayed_work work;
+	struct edp_manager *manager;
+	struct power_supply *psy;
+};
+
+static int depl_psy_get_property(struct depl_driver *drv,
+		enum power_supply_property psp, int *val)
+{
+	union power_supply_propval pv;
+
+	if (drv->psy->get_property(drv->psy, psp, &pv))
+		return -EFAULT;
+	*val = pv.intval;
+	return 0;
+}
+
+static int depl_psy_ocv(struct depl_driver *drv)
+{
+	int val;
+	if (depl_psy_get_property(drv, POWER_SUPPLY_PROP_VOLTAGE_OCV, &val))
+		return drv->pdata->vsys_min;
+	return val;
+}
+
+static int depl_psy_capacity(struct depl_driver *drv)
+{
+	int val;
+	if (depl_psy_get_property(drv, POWER_SUPPLY_PROP_CAPACITY, &val))
+		return 0;
+	return val;
+}
+
+static unsigned int depl_psy_temp(struct depl_driver *drv)
+{
+	int val;
+	if (depl_psy_get_property(drv, POWER_SUPPLY_PROP_TEMP, &val))
+		return 25;
+	return max(0, val);
+}
+
+static inline unsigned int depl_maximum(struct depl_driver *drv)
+{
+	return drv->client.states[0];
+}
+
+/* Given two points (x1, y1) and (x2, y2), find the y coord of x */
+static int depl_interpolate(int x, int x1, int y1, int x2, int y2)
+{
+	if (x1 == x2)
+		return y1;
+	return (y2 * (x - x1) - y1 * (x - x2)) / (x2 - x1);
+}
+
+/* Calc RBAT for current capacity (SOC) */
+static int depl_rbat(struct depl_driver *drv)
+{
+	struct psy_depletion_rbat_lut *p;
+	struct psy_depletion_rbat_lut *q;
+	unsigned int capacity;
+	int rbat;
+
+	capacity = depl_psy_capacity(drv);
+	p = drv->pdata->rbat_lut;
+
+	while (p->capacity > capacity)
+		p++;
+
+	if (p == drv->pdata->rbat_lut)
+		return p->rbat;
+
+	q = p - 1;
+
+	rbat = depl_interpolate(capacity, p->capacity, p->rbat,
+			q->capacity, q->rbat);
+	rbat += drv->pdata->r_const;
+
+	pr_debug("capacity : %u\n", capacity);
+	pr_debug("rbat     : %d\n", rbat);
+
+	return rbat;
+}
+
+static s64 depl_ibat_possible(struct depl_driver *drv, s64 ocv, s64 rbat)
+{
+	return div64_s64(1000 * (ocv - drv->pdata->vsys_min), rbat);
+}
+
+/* Calc IBAT for a given temperature */
+static int depl_ibat(struct depl_driver *drv, unsigned int temp)
+{
+	struct psy_depletion_ibat_lut *p;
+	struct psy_depletion_ibat_lut *q;
+	int ibat;
+
+	p = drv->pdata->ibat_lut;
+	while (p->ibat && p->temp > temp)
+		p++;
+
+	if (p == drv->pdata->ibat_lut || !p->ibat)
+		return p->ibat;
+
+	q = p - 1;
+	ibat = depl_interpolate(temp, p->temp, p->ibat, q->temp, q->ibat);
+
+	pr_debug("temp     : %d\n", temp);
+	pr_debug("ibat     : %d\n", ibat);
+
+	return ibat;
+}
+
+static s64 depl_pbat(s64 ocv, s64 ibat, s64 rbat)
+{
+	s64 pbat;
+	pbat = ocv - div64_s64(ibat * rbat, 1000);
+	pbat = div64_s64(pbat * ibat, 1000000);
+	return pbat;
+}
+
+static unsigned int depl_calc(struct depl_driver *drv)
+{
+	s64 ocv;
+	s64 rbat;
+	s64 ibat_pos;
+	s64 ibat_tbat;
+	s64 ibat_lcm;
+	s64 pbat_lcm;
+	s64 pbat_nom;
+	s64 pbat_gain;
+	s64 depl;
+
+	ocv = depl_psy_ocv(drv);
+	rbat = depl_rbat(drv);
+
+	ibat_pos = depl_ibat_possible(drv, ocv, rbat);
+	ibat_tbat = depl_ibat(drv, depl_psy_temp(drv));
+	ibat_lcm = min(ibat_pos, ibat_tbat);
+
+	pbat_lcm = depl_pbat(ocv, ibat_lcm, rbat);
+	pbat_nom = depl_pbat(drv->pdata->vcharge, drv->pdata->ibat_nom, rbat);
+	pbat_gain = div64_s64(drv->manager->max * 1000, pbat_nom);
+
+	depl = drv->manager->max - div64_s64(pbat_gain * pbat_lcm, 1000);
+
+	pr_debug("ocv      : %lld\n", ocv);
+	pr_debug("ibat_pos : %lld\n", ibat_pos);
+	pr_debug("ibat_tbat: %lld\n", ibat_tbat);
+	pr_debug("ibat_lcm : %lld\n", ibat_lcm);
+	pr_debug("pbat_lcm : %lld\n", pbat_lcm);
+	pr_debug("pbat_nom : %lld\n", pbat_nom);
+	pr_debug("pbat_gain: %lld\n", pbat_gain);
+	pr_debug("depletion: %lld\n", depl);
+
+	depl = clamp_t(s64, depl, 0, depl_maximum(drv));
+	return depl;
+}
+
+static void depl_update(struct work_struct *work)
+{
+	struct depl_driver *drv;
+	struct edp_client *c;
+	unsigned int depl;
+	unsigned int i;
+
+	drv = container_of(work, struct depl_driver, work.work);
+	c = &drv->client;
+	depl = depl_calc(drv);
+
+	i = c->num_states - 1;
+	while (i && c->states[i] < depl)
+		i--;
+
+	edp_update_client_request(c, i, NULL);
+
+	schedule_delayed_work(to_delayed_work(work),
+			msecs_to_jiffies(DEPL_INTERVAL));
+}
+
+/* Nothing to do */
+static void depl_edp_callback(unsigned int new_state, void *priv_data)
+{
+}
+
+static void depl_shutdown(struct platform_device *pdev)
+{
+	struct depl_driver *drv = platform_get_drvdata(pdev);
+	cancel_delayed_work_sync(&drv->work);
+}
+
+static int depl_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	depl_shutdown(pdev);
+	return 0;
+}
+
+static int depl_resume(struct platform_device *pdev)
+{
+	struct depl_driver *drv = platform_get_drvdata(pdev);
+	schedule_delayed_work(&drv->work, 0);
+	return 0;
+}
+
+static __devinit int depl_probe(struct platform_device *pdev)
+{
+	struct depl_driver *drv;
+	struct edp_manager *m;
+	struct edp_client *c;
+	int r = -EFAULT;
+
+	if (!pdev->dev.platform_data)
+		return -EINVAL;
+
+	m = edp_get_manager("battery");
+	if (!m) {
+		dev_err(&pdev->dev, "could not get EDP manager\n");
+		return -ENODEV;
+	}
+
+	drv = devm_kzalloc(&pdev->dev, sizeof(*drv), GFP_KERNEL);
+	if (!drv)
+		return -ENOMEM;
+
+	drv->pdata = pdev->dev.platform_data;
+	drv->manager = m;
+	drv->psy = power_supply_get_by_name(drv->pdata->power_supply);
+	if (!drv->psy)
+		goto fail;
+
+	c = &drv->client;
+	strncpy(c->name, "depletion", EDP_NAME_LEN - 1);
+	c->name[EDP_NAME_LEN - 1] = 0;
+	c->priority = EDP_MAX_PRIO;
+	c->throttle = depl_edp_callback;
+	c->notify_promotion = depl_edp_callback;
+	c->states = drv->pdata->states;
+	c->num_states = drv->pdata->num_states;
+	c->e0_index = drv->pdata->e0_index;
+
+	r = edp_register_client(m, c);
+	if (r) {
+		dev_err(&pdev->dev, "failed to register: %d\n", r);
+		goto fail;
+	}
+
+	platform_set_drvdata(pdev, drv);
+	INIT_DELAYED_WORK_DEFERRABLE(&drv->work, depl_update);
+	schedule_delayed_work(&drv->work, 0);
+	return 0;
+
+fail:
+	devm_kfree(&pdev->dev, drv);
+	return r;
+}
+
+static struct platform_driver depl_driver = {
+	.probe = depl_probe,
+	.shutdown = depl_shutdown,
+	.suspend = depl_suspend,
+	.resume = depl_resume,
+	.driver = {
+		.name = "psy_depletion",
+		.owner = THIS_MODULE
+	}
+};
+
+static __init int depl_init(void)
+{
+	return platform_driver_register(&depl_driver);
+}
+late_initcall(depl_init);