diff options
Diffstat (limited to 'drivers/macintosh')
| -rw-r--r-- | drivers/macintosh/windfarm_ad7417_sensor.c | 347 |
1 files changed, 347 insertions, 0 deletions
diff --git a/drivers/macintosh/windfarm_ad7417_sensor.c b/drivers/macintosh/windfarm_ad7417_sensor.c new file mode 100644 index 00000000000..ac3f243b9c5 --- /dev/null +++ b/drivers/macintosh/windfarm_ad7417_sensor.c @@ -0,0 +1,347 @@ +/* + * 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 __devinit 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 __devinit 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 __devinit 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 __devexit 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 __devinit 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 __devexit 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"); + |