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powerpc/windfarm: Add ad7417 sensor
For user by the upcoming windfarm_pm72 and windfarm_rm31 Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Benjamin Herrenschmidt
parent
33e6820b76
commit
850dc32168
347
drivers/macintosh/windfarm_ad7417_sensor.c
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347
drivers/macintosh/windfarm_ad7417_sensor.c
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@ -0,0 +1,347 @@
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/*
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* Windfarm PowerMac thermal control. AD7417 sensors
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*
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* Copyright 2012 Benjamin Herrenschmidt, IBM Corp.
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*
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* Released under the term of the GNU GPL v2.
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*/
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#include <linux/types.h>
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/delay.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/wait.h>
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#include <linux/i2c.h>
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#include <asm/prom.h>
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#include <asm/machdep.h>
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#include <asm/io.h>
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#include <asm/sections.h>
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#include "windfarm.h"
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#include "windfarm_mpu.h"
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#define VERSION "1.0"
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struct wf_ad7417_priv {
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struct kref ref;
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struct i2c_client *i2c;
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u8 config;
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u8 cpu;
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const struct mpu_data *mpu;
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struct wf_sensor sensors[5];
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struct mutex lock;
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};
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static int wf_ad7417_temp_get(struct wf_sensor *sr, s32 *value)
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{
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struct wf_ad7417_priv *pv = sr->priv;
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u8 buf[2];
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s16 raw;
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int rc;
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*value = 0;
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mutex_lock(&pv->lock);
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/* Read temp register */
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buf[0] = 0;
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rc = i2c_master_send(pv->i2c, buf, 1);
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if (rc < 0)
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goto error;
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rc = i2c_master_recv(pv->i2c, buf, 2);
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if (rc < 0)
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goto error;
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/* Read a a 16-bit signed value */
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raw = be16_to_cpup((__le16 *)buf);
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/* Convert 8.8-bit to 16.16 fixed point */
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*value = ((s32)raw) << 8;
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mutex_unlock(&pv->lock);
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return 0;
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error:
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mutex_unlock(&pv->lock);
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return -1;
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}
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/*
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* Scaling factors for the AD7417 ADC converters (except
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* for the CPU diode which is obtained from the EEPROM).
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* Those values are obtained from the property list of
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* the darwin driver
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*/
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#define ADC_12V_CURRENT_SCALE 0x0320 /* _AD2 */
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#define ADC_CPU_VOLTAGE_SCALE 0x00a0 /* _AD3 */
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#define ADC_CPU_CURRENT_SCALE 0x1f40 /* _AD4 */
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static void wf_ad7417_adc_convert(struct wf_ad7417_priv *pv,
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int chan, s32 raw, s32 *value)
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{
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switch(chan) {
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case 1: /* Diode */
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*value = (raw * (s32)pv->mpu->mdiode +
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((s32)pv->mpu->bdiode << 12)) >> 2;
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break;
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case 2: /* 12v current */
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*value = raw * ADC_12V_CURRENT_SCALE;
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break;
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case 3: /* core voltage */
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*value = raw * ADC_CPU_VOLTAGE_SCALE;
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break;
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case 4: /* core current */
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*value = raw * ADC_CPU_CURRENT_SCALE;
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break;
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}
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}
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static int wf_ad7417_adc_get(struct wf_sensor *sr, s32 *value)
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{
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struct wf_ad7417_priv *pv = sr->priv;
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int chan = sr - pv->sensors;
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int i, rc;
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u8 buf[2];
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u16 raw;
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*value = 0;
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mutex_lock(&pv->lock);
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for (i = 0; i < 10; i++) {
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/* Set channel */
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buf[0] = 1;
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buf[1] = (pv->config & 0x1f) | (chan << 5);
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rc = i2c_master_send(pv->i2c, buf, 2);
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if (rc < 0)
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goto error;
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/* Wait for conversion */
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msleep(1);
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/* Switch to data register */
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buf[0] = 4;
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rc = i2c_master_send(pv->i2c, buf, 1);
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if (rc < 0)
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goto error;
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/* Read result */
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rc = i2c_master_recv(pv->i2c, buf, 2);
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if (rc < 0)
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goto error;
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/* Read a a 16-bit signed value */
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raw = be16_to_cpup((__le16 *)buf) >> 6;
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wf_ad7417_adc_convert(pv, chan, raw, value);
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dev_vdbg(&pv->i2c->dev, "ADC chan %d [%s]"
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" raw value: 0x%x, conv to: 0x%08x\n",
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chan, sr->name, raw, *value);
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mutex_unlock(&pv->lock);
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return 0;
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error:
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dev_dbg(&pv->i2c->dev,
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"Error reading ADC, try %d...\n", i);
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if (i < 9)
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msleep(10);
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}
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mutex_unlock(&pv->lock);
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return -1;
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}
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static void wf_ad7417_release(struct kref *ref)
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{
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struct wf_ad7417_priv *pv = container_of(ref,
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struct wf_ad7417_priv, ref);
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kfree(pv);
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}
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static void wf_ad7417_sensor_release(struct wf_sensor *sr)
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{
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struct wf_ad7417_priv *pv = sr->priv;
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kfree(sr->name);
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kref_put(&pv->ref, wf_ad7417_release);
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}
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static const struct wf_sensor_ops wf_ad7417_temp_ops = {
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.get_value = wf_ad7417_temp_get,
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.release = wf_ad7417_sensor_release,
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.owner = THIS_MODULE,
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};
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static const struct wf_sensor_ops wf_ad7417_adc_ops = {
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.get_value = wf_ad7417_adc_get,
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.release = wf_ad7417_sensor_release,
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.owner = THIS_MODULE,
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};
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static void __devinit wf_ad7417_add_sensor(struct wf_ad7417_priv *pv,
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int index, const char *name,
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const struct wf_sensor_ops *ops)
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{
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pv->sensors[index].name = kasprintf(GFP_KERNEL, "%s-%d", name, pv->cpu);
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pv->sensors[index].priv = pv;
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pv->sensors[index].ops = ops;
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if (!wf_register_sensor(&pv->sensors[index]))
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kref_get(&pv->ref);
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}
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static void __devinit wf_ad7417_init_chip(struct wf_ad7417_priv *pv)
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{
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int rc;
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u8 buf[2];
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u8 config = 0;
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/*
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* Read ADC the configuration register and cache it. We
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* also make sure Config2 contains proper values, I've seen
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* cases where we got stale grabage in there, thus preventing
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* proper reading of conv. values
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*/
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/* Clear Config2 */
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buf[0] = 5;
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buf[1] = 0;
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i2c_master_send(pv->i2c, buf, 2);
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/* Read & cache Config1 */
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buf[0] = 1;
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rc = i2c_master_send(pv->i2c, buf, 1);
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if (rc > 0) {
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rc = i2c_master_recv(pv->i2c, buf, 1);
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if (rc > 0) {
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config = buf[0];
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dev_dbg(&pv->i2c->dev, "ADC config reg: %02x\n",
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config);
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/* Disable shutdown mode */
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config &= 0xfe;
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buf[0] = 1;
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buf[1] = config;
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rc = i2c_master_send(pv->i2c, buf, 2);
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}
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}
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if (rc <= 0)
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dev_err(&pv->i2c->dev, "Error reading ADC config\n");
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pv->config = config;
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}
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static int __devinit wf_ad7417_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct wf_ad7417_priv *pv;
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const struct mpu_data *mpu;
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const char *loc;
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int cpu_nr;
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loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
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if (!loc) {
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dev_warn(&client->dev, "Missing hwsensor-location property!\n");
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return -ENXIO;
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}
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/*
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* Identify which CPU we belong to by looking at the first entry
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* in the hwsensor-location list
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*/
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if (!strncmp(loc, "CPU A", 5))
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cpu_nr = 0;
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else if (!strncmp(loc, "CPU B", 5))
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cpu_nr = 1;
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else {
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pr_err("wf_ad7417: Can't identify location %s\n", loc);
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return -ENXIO;
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}
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mpu = wf_get_mpu(cpu_nr);
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if (!mpu) {
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dev_err(&client->dev, "Failed to retrieve MPU data\n");
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return -ENXIO;
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}
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pv = kzalloc(sizeof(struct wf_ad7417_priv), GFP_KERNEL);
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if (pv == NULL)
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return -ENODEV;
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kref_init(&pv->ref);
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mutex_init(&pv->lock);
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pv->i2c = client;
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pv->cpu = cpu_nr;
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pv->mpu = mpu;
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dev_set_drvdata(&client->dev, pv);
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/* Initialize the chip */
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wf_ad7417_init_chip(pv);
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/*
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* We cannot rely on Apple device-tree giving us child
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* node with the names of the individual sensors so we
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* just hard code what we know about them
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*/
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wf_ad7417_add_sensor(pv, 0, "cpu-amb-temp", &wf_ad7417_temp_ops);
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wf_ad7417_add_sensor(pv, 1, "cpu-diode-temp", &wf_ad7417_adc_ops);
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wf_ad7417_add_sensor(pv, 2, "cpu-12v-current", &wf_ad7417_adc_ops);
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wf_ad7417_add_sensor(pv, 3, "cpu-voltage", &wf_ad7417_adc_ops);
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wf_ad7417_add_sensor(pv, 4, "cpu-current", &wf_ad7417_adc_ops);
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return 0;
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}
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static int __devexit wf_ad7417_remove(struct i2c_client *client)
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{
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struct wf_ad7417_priv *pv = dev_get_drvdata(&client->dev);
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int i;
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/* Mark client detached */
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pv->i2c = NULL;
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/* Release sensor */
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for (i = 0; i < 5; i++)
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wf_unregister_sensor(&pv->sensors[i]);
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kref_put(&pv->ref, wf_ad7417_release);
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return 0;
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}
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static const struct i2c_device_id wf_ad7417_id[] = {
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{ "MAC,ad7417", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, wf_ad7417_id);
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static struct i2c_driver wf_ad7417_driver = {
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.driver = {
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.name = "wf_ad7417",
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},
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.probe = wf_ad7417_probe,
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.remove = wf_ad7417_remove,
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.id_table = wf_ad7417_id,
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};
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static int __devinit wf_ad7417_init(void)
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{
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/* This is only supported on these machines */
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if (!of_machine_is_compatible("PowerMac7,2") &&
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!of_machine_is_compatible("PowerMac7,3") &&
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!of_machine_is_compatible("RackMac3,1"))
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return -ENODEV;
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return i2c_add_driver(&wf_ad7417_driver);
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}
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static void __devexit wf_ad7417_exit(void)
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{
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i2c_del_driver(&wf_ad7417_driver);
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}
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module_init(wf_ad7417_init);
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module_exit(wf_ad7417_exit);
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MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
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MODULE_DESCRIPTION("ad7417 sensor driver for PowerMacs");
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MODULE_LICENSE("GPL");
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