--- /dev/null
+/*
+ * Windfarm PowerMac thermal control. AD7417 sensors
+ *
+ * Copyright 2012 Benjamin Herrenschmidt, IBM Corp.
+ *
+ * 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/i2c.h>
+#include <asm/prom.h>
+#include <asm/machdep.h>
+#include <asm/io.h>
+#include <asm/sections.h>
+
+#include "windfarm.h"
+#include "windfarm_mpu.h"
+
+#define VERSION "1.0"
+
+struct wf_ad7417_priv {
+ struct kref ref;
+ struct i2c_client *i2c;
+ u8 config;
+ u8 cpu;
+ const struct mpu_data *mpu;
+ struct wf_sensor sensors[5];
+ struct mutex lock;
+};
+
+static int wf_ad7417_temp_get(struct wf_sensor *sr, s32 *value)
+{
+ struct wf_ad7417_priv *pv = sr->priv;
+ u8 buf[2];
+ s16 raw;
+ int rc;
+
+ *value = 0;
+ mutex_lock(&pv->lock);
+
+ /* Read temp register */
+ buf[0] = 0;
+ rc = i2c_master_send(pv->i2c, buf, 1);
+ if (rc < 0)
+ goto error;
+ rc = i2c_master_recv(pv->i2c, buf, 2);
+ if (rc < 0)
+ goto error;
+
+ /* Read a a 16-bit signed value */
+ raw = be16_to_cpup((__le16 *)buf);
+
+ /* Convert 8.8-bit to 16.16 fixed point */
+ *value = ((s32)raw) << 8;
+
+ mutex_unlock(&pv->lock);
+ return 0;
+
+error:
+ mutex_unlock(&pv->lock);
+ return -1;
+}
+
+/*
+ * Scaling factors for the AD7417 ADC converters (except
+ * for the CPU diode which is obtained from the EEPROM).
+ * Those values are obtained from the property list of
+ * the darwin driver
+ */
+#define ADC_12V_CURRENT_SCALE 0x0320 /* _AD2 */
+#define ADC_CPU_VOLTAGE_SCALE 0x00a0 /* _AD3 */
+#define ADC_CPU_CURRENT_SCALE 0x1f40 /* _AD4 */
+
+static void wf_ad7417_adc_convert(struct wf_ad7417_priv *pv,
+ int chan, s32 raw, s32 *value)
+{
+ switch(chan) {
+ case 1: /* Diode */
+ *value = (raw * (s32)pv->mpu->mdiode +
+ ((s32)pv->mpu->bdiode << 12)) >> 2;
+ break;
+ case 2: /* 12v current */
+ *value = raw * ADC_12V_CURRENT_SCALE;
+ break;
+ case 3: /* core voltage */
+ *value = raw * ADC_CPU_VOLTAGE_SCALE;
+ break;
+ case 4: /* core current */
+ *value = raw * ADC_CPU_CURRENT_SCALE;
+ break;
+ }
+}
+
+static int wf_ad7417_adc_get(struct wf_sensor *sr, s32 *value)
+{
+ struct wf_ad7417_priv *pv = sr->priv;
+ int chan = sr - pv->sensors;
+ int i, rc;
+ u8 buf[2];
+ u16 raw;
+
+ *value = 0;
+ mutex_lock(&pv->lock);
+ for (i = 0; i < 10; i++) {
+ /* Set channel */
+ buf[0] = 1;
+ buf[1] = (pv->config & 0x1f) | (chan << 5);
+ rc = i2c_master_send(pv->i2c, buf, 2);
+ if (rc < 0)
+ goto error;
+
+ /* Wait for conversion */
+ msleep(1);
+
+ /* Switch to data register */
+ buf[0] = 4;
+ rc = i2c_master_send(pv->i2c, buf, 1);
+ if (rc < 0)
+ goto error;
+
+ /* Read result */
+ rc = i2c_master_recv(pv->i2c, buf, 2);
+ if (rc < 0)
+ goto error;
+
+ /* Read a a 16-bit signed value */
+ raw = be16_to_cpup((__le16 *)buf) >> 6;
+ wf_ad7417_adc_convert(pv, chan, raw, value);
+
+ dev_vdbg(&pv->i2c->dev, "ADC chan %d [%s]"
+ " raw value: 0x%x, conv to: 0x%08x\n",
+ chan, sr->name, raw, *value);
+
+ mutex_unlock(&pv->lock);
+ return 0;
+
+ error:
+ dev_dbg(&pv->i2c->dev,
+ "Error reading ADC, try %d...\n", i);
+ if (i < 9)
+ msleep(10);
+ }
+ mutex_unlock(&pv->lock);
+ return -1;
+}
+
+static void wf_ad7417_release(struct kref *ref)
+{
+ struct wf_ad7417_priv *pv = container_of(ref,
+ struct wf_ad7417_priv, ref);
+ kfree(pv);
+}
+
+static void wf_ad7417_sensor_release(struct wf_sensor *sr)
+{
+ struct wf_ad7417_priv *pv = sr->priv;
+
+ kfree(sr->name);
+ kref_put(&pv->ref, wf_ad7417_release);
+}
+
+static const struct wf_sensor_ops wf_ad7417_temp_ops = {
+ .get_value = wf_ad7417_temp_get,
+ .release = wf_ad7417_sensor_release,
+ .owner = THIS_MODULE,
+};
+
+static const struct wf_sensor_ops wf_ad7417_adc_ops = {
+ .get_value = wf_ad7417_adc_get,
+ .release = wf_ad7417_sensor_release,
+ .owner = THIS_MODULE,
+};
+
+static void wf_ad7417_add_sensor(struct wf_ad7417_priv *pv,
+ int index, const char *name,
+ const struct wf_sensor_ops *ops)
+{
+ pv->sensors[index].name = kasprintf(GFP_KERNEL, "%s-%d", name, pv->cpu);
+ pv->sensors[index].priv = pv;
+ pv->sensors[index].ops = ops;
+ if (!wf_register_sensor(&pv->sensors[index]))
+ kref_get(&pv->ref);
+}
+
+static void wf_ad7417_init_chip(struct wf_ad7417_priv *pv)
+{
+ int rc;
+ u8 buf[2];
+ u8 config = 0;
+
+ /*
+ * Read ADC the configuration register and cache it. We
+ * also make sure Config2 contains proper values, I've seen
+ * cases where we got stale grabage in there, thus preventing
+ * proper reading of conv. values
+ */
+
+ /* Clear Config2 */
+ buf[0] = 5;
+ buf[1] = 0;
+ i2c_master_send(pv->i2c, buf, 2);
+
+ /* Read & cache Config1 */
+ buf[0] = 1;
+ rc = i2c_master_send(pv->i2c, buf, 1);
+ if (rc > 0) {
+ rc = i2c_master_recv(pv->i2c, buf, 1);
+ if (rc > 0) {
+ config = buf[0];
+
+ dev_dbg(&pv->i2c->dev, "ADC config reg: %02x\n",
+ config);
+
+ /* Disable shutdown mode */
+ config &= 0xfe;
+ buf[0] = 1;
+ buf[1] = config;
+ rc = i2c_master_send(pv->i2c, buf, 2);
+ }
+ }
+ if (rc <= 0)
+ dev_err(&pv->i2c->dev, "Error reading ADC config\n");
+
+ pv->config = config;
+}
+
+static int wf_ad7417_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct wf_ad7417_priv *pv;
+ const struct mpu_data *mpu;
+ const char *loc;
+ int cpu_nr;
+
+ loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
+ if (!loc) {
+ dev_warn(&client->dev, "Missing hwsensor-location property!\n");
+ return -ENXIO;
+ }
+
+ /*
+ * Identify which CPU we belong to by looking at the first entry
+ * in the hwsensor-location list
+ */
+ if (!strncmp(loc, "CPU A", 5))
+ cpu_nr = 0;
+ else if (!strncmp(loc, "CPU B", 5))
+ cpu_nr = 1;
+ else {
+ pr_err("wf_ad7417: Can't identify location %s\n", loc);
+ return -ENXIO;
+ }
+ mpu = wf_get_mpu(cpu_nr);
+ if (!mpu) {
+ dev_err(&client->dev, "Failed to retrieve MPU data\n");
+ return -ENXIO;
+ }
+
+ pv = kzalloc(sizeof(struct wf_ad7417_priv), GFP_KERNEL);
+ if (pv == NULL)
+ return -ENODEV;
+
+ kref_init(&pv->ref);
+ mutex_init(&pv->lock);
+ pv->i2c = client;
+ pv->cpu = cpu_nr;
+ pv->mpu = mpu;
+ dev_set_drvdata(&client->dev, pv);
+
+ /* Initialize the chip */
+ wf_ad7417_init_chip(pv);
+
+ /*
+ * We cannot rely on Apple device-tree giving us child
+ * node with the names of the individual sensors so we
+ * just hard code what we know about them
+ */
+ wf_ad7417_add_sensor(pv, 0, "cpu-amb-temp", &wf_ad7417_temp_ops);
+ wf_ad7417_add_sensor(pv, 1, "cpu-diode-temp", &wf_ad7417_adc_ops);
+ wf_ad7417_add_sensor(pv, 2, "cpu-12v-current", &wf_ad7417_adc_ops);
+ wf_ad7417_add_sensor(pv, 3, "cpu-voltage", &wf_ad7417_adc_ops);
+ wf_ad7417_add_sensor(pv, 4, "cpu-current", &wf_ad7417_adc_ops);
+
+ return 0;
+}
+
+static int wf_ad7417_remove(struct i2c_client *client)
+{
+ struct wf_ad7417_priv *pv = dev_get_drvdata(&client->dev);
+ int i;
+
+ /* Mark client detached */
+ pv->i2c = NULL;
+
+ /* Release sensor */
+ for (i = 0; i < 5; i++)
+ wf_unregister_sensor(&pv->sensors[i]);
+
+ kref_put(&pv->ref, wf_ad7417_release);
+
+ return 0;
+}
+
+static const struct i2c_device_id wf_ad7417_id[] = {
+ { "MAC,ad7417", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, wf_ad7417_id);
+
+static struct i2c_driver wf_ad7417_driver = {
+ .driver = {
+ .name = "wf_ad7417",
+ },
+ .probe = wf_ad7417_probe,
+ .remove = wf_ad7417_remove,
+ .id_table = wf_ad7417_id,
+};
+
+static int wf_ad7417_init(void)
+{
+ /* This is only supported on these machines */
+ if (!of_machine_is_compatible("PowerMac7,2") &&
+ !of_machine_is_compatible("PowerMac7,3") &&
+ !of_machine_is_compatible("RackMac3,1"))
+ return -ENODEV;
+
+ return i2c_add_driver(&wf_ad7417_driver);
+}
+
+static void wf_ad7417_exit(void)
+{
+ i2c_del_driver(&wf_ad7417_driver);
+}
+
+module_init(wf_ad7417_init);
+module_exit(wf_ad7417_exit);
+
+MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
+MODULE_DESCRIPTION("ad7417 sensor driver for PowerMacs");
+MODULE_LICENSE("GPL");
+
Code Review / kvmfornfv.git / blobdiff