[UPSTREAM] Attempt at improving ADC access
Balaji Rao
balajirrao at openmoko.org
Thu Oct 16 20:58:03 CEST 2008
On Thu, Oct 16, 2008 at 06:31:47AM -0200, Werner Almesberger wrote:
> Balaji Rao wrote:
> > Ah, now I remember! From the proposed sync callback, we wouldn't know
> > which completion to complete as we wouldn't be passed the adc_request
> > object. We could very well look at the queue head, but that would not be
> > a clean way to do it. What do you say ?
>
> How about passing the request ? Or a void pointer that's passed to
> the callback function, which then does with it whatever it wants,
> i.e., the usual
>
> ..., void (*fn)(void *arg), void *arg, ...
>
> idiom.
How does this look now ?
diff --git a/drivers/i2c/chips/pcf50633.c b/drivers/i2c/chips/pcf50633.c
index 13b3158..8eeaf46 100644
--- a/drivers/i2c/chips/pcf50633.c
+++ b/drivers/i2c/chips/pcf50633.c
@@ -117,6 +117,16 @@ enum pcf50633_suspend_states {
PCF50633_SS_COMPLETED_RESUME,
};
+struct adc_request {
+ int mux;
+ int avg;
+ int result;
+ void (*callback)(struct pcf50633_data *, void *, int);
+ void *callback_param;
+
+ /* Used in case of sync requests */
+ struct completion completion;
+};
struct pcf50633_data {
struct i2c_client *client;
@@ -160,14 +170,10 @@ struct pcf50633_data {
int coldplug_done; /* cleared by probe, set by first work service */
int flag_bat_voltage_read; /* ipc to /sys batt voltage read func */
- int charger_adc_result_raw;
- enum charger_type charger_type;
-
/* we have a FIFO of ADC measurement requests that are used only by
* the workqueue service code after the ADC completion interrupt
*/
- int adc_queue_mux[MAX_ADC_FIFO_DEPTH]; /* which ADC input to use */
- int adc_queue_avg[MAX_ADC_FIFO_DEPTH]; /* amount of averaging */
+ struct adc_request *adc_queue[MAX_ADC_FIFO_DEPTH]; /* amount of averaging */
int adc_queue_head; /* head owned by foreground code */
int adc_queue_tail; /* tail owned by service code */
@@ -299,7 +305,7 @@ static void async_adc_read_setup(struct pcf50633_data *pcf,
}
-static u_int16_t async_adc_complete(struct pcf50633_data *pcf)
+static u_int16_t adc_read_result(struct pcf50633_data *pcf)
{
u_int16_t ret = (__reg_read(pcf, PCF50633_REG_ADCS1) << 2) |
(__reg_read(pcf, PCF50633_REG_ADCS3) &
@@ -555,9 +561,14 @@ static int interpret_charger_type_from_adc(struct pcf50633_data *pcf,
-static void configure_pmu_for_charger(struct pcf50633_data *pcf,
- enum charger_type type)
+static void
+configure_pmu_for_charger(struct pcf50633_data *pcf,
+ void *unused, int adc_result_raw)
{
+ int type;
+
+ type = interpret_charger_type_from_adc(
+ pcf, adc_result_raw);
switch (type) {
case CHARGER_TYPE_NONE:
pcf50633_usb_curlim_set(pcf, 0);
@@ -605,16 +616,16 @@ static void trigger_next_adc_job_if_any(struct pcf50633_data *pcf)
if (pcf->adc_queue_head == pcf->adc_queue_tail)
return;
async_adc_read_setup(pcf,
- pcf->adc_queue_mux[pcf->adc_queue_tail],
- pcf->adc_queue_avg[pcf->adc_queue_tail]);
+ pcf->adc_queue[pcf->adc_queue_tail]->mux,
+ pcf->adc_queue[pcf->adc_queue_tail]->avg);
}
-static void add_request_to_adc_queue(struct pcf50633_data *pcf,
- int mux, int avg)
+
+static void
+adc_add_request_to_queue(struct pcf50633_data *pcf, struct adc_request *req)
{
int old_head = pcf->adc_queue_head;
- pcf->adc_queue_mux[pcf->adc_queue_head] = mux;
- pcf->adc_queue_avg[pcf->adc_queue_head] = avg;
+ pcf->adc_queue[pcf->adc_queue_head] = req;
pcf->adc_queue_head = (pcf->adc_queue_head + 1) &
(MAX_ADC_FIFO_DEPTH - 1);
@@ -624,6 +635,65 @@ static void add_request_to_adc_queue(struct pcf50633_data *pcf,
trigger_next_adc_job_if_any(pcf);
}
+static void
+__adc_sync_read_callback(struct pcf50633_data *pcf, void *param, int result)
+{
+ struct adc_request *req;
+
+ /*We know here that the passed param is an adc_request object */
+ req = (struct adc_request *)param;
+
+ req->result = result;
+ complete(&req->completion);
+}
+
+int adc_sync_read(struct pcf50633_data *pcf, int mux, int avg)
+{
+
+ struct adc_request *req;
+ int result;
+
+ /* req is freed when the result is ready, in pcf50633_work*/
+ req = kmalloc(sizeof(*req), GFP_KERNEL);
+ if (!req)
+ return -ENOMEM;
+
+ req->mux = mux;
+ req->avg = avg;
+ req->callback = __adc_sync_read_callback;
+ req->callback_param = req;
+ init_completion(&req->completion);
+
+ adc_add_request_to_queue(pcf, req);
+
+ wait_for_completion(&req->completion);
+ result = req->result;
+ kfree(req);
+
+ return result;
+}
+
+int adc_async_read(struct pcf50633_data *pcf, int mux, int avg,
+ void (*callback)(struct pcf50633_data *, void *,int),
+ void *callback_param)
+{
+ struct adc_request *req;
+
+ /* req is freed when the result is ready, in pcf50633_work*/
+ req = kmalloc(sizeof(*req), GFP_KERNEL);
+ if (!req)
+ return -ENOMEM;
+
+ req->mux = mux;
+ req->avg = avg;
+ req->callback = callback;
+ req->callback_param = callback_param;
+
+ adc_add_request_to_queue(pcf, req);
+
+ return 0;
+}
+
/*
* we get run to handle servicing the async notification from USB stack that
* we got enumerated and allowed to draw a particular amount of current
@@ -744,8 +814,10 @@ static void pcf50633_work_nobat(struct work_struct *work)
pcf->jiffies_last_bat_ins = jiffies;
/* figure out our charging stance */
- add_request_to_adc_queue(pcf, PCF50633_ADCC1_MUX_ADCIN1,
- PCF50633_ADCC1_AVERAGE_16);
+ (void)adc_async_read(pcf, PCF50633_ADCC1_MUX_ADCIN1,
+ PCF50633_ADCC1_AVERAGE_16,
+ configure_pmu_for_charger,
+ NULL);
goto bail;
}
@@ -768,6 +840,7 @@ static void pcf50633_work(struct work_struct *work)
u_int8_t pcfirq[5];
int ret;
int tail;
+ struct adc_request *req;
mutex_lock(&pcf->working_lock);
pcf->working = 1;
@@ -873,8 +946,9 @@ static void pcf50633_work(struct work_struct *work)
}
/* figure out our initial charging stance */
- add_request_to_adc_queue(pcf, PCF50633_ADCC1_MUX_ADCIN1,
- PCF50633_ADCC1_AVERAGE_16);
+ (void)adc_async_read(pcf, PCF50633_ADCC1_MUX_ADCIN1,
+ PCF50633_ADCC1_AVERAGE_16,
+ configure_pmu_for_charger, NULL);
pcf->coldplug_done = 1;
}
@@ -912,8 +986,9 @@ static void pcf50633_work(struct work_struct *work)
PCF50633_FEAT_MBC, PMU_EVT_USB_INSERT);
msleep(500); /* debounce, allow to see any ID resistor */
/* completion irq will figure out our charging stance */
- add_request_to_adc_queue(pcf, PCF50633_ADCC1_MUX_ADCIN1,
- PCF50633_ADCC1_AVERAGE_16);
+ (void)adc_async_read(pcf, PCF50633_ADCC1_MUX_ADCIN1,
+ PCF50633_ADCC1_AVERAGE_16,
+ configure_pmu_for_charger, NULL);
}
if (pcfirq[0] & PCF50633_INT1_USBREM &&
!(pcfirq[0] & PCF50633_INT1_USBINS)) {
@@ -938,8 +1013,9 @@ static void pcf50633_work(struct work_struct *work)
pcf->last_curlim_set = 0;
/* completion irq will figure out our charging stance */
- add_request_to_adc_queue(pcf, PCF50633_ADCC1_MUX_ADCIN1,
- PCF50633_ADCC1_AVERAGE_16);
+ (void)adc_async_read(pcf, PCF50633_ADCC1_MUX_ADCIN1,
+ PCF50633_ADCC1_AVERAGE_16,
+ configure_pmu_for_charger, NULL);
}
}
if (pcfirq[0] & PCF50633_INT1_ALARM) {
@@ -1080,21 +1156,11 @@ static void pcf50633_work(struct work_struct *work)
tail = pcf->adc_queue_tail;
pcf->adc_queue_tail = (pcf->adc_queue_tail + 1) &
(MAX_ADC_FIFO_DEPTH - 1);
+ req = pcf->adc_queue[tail];
+ req->callback(pcf, req->callback_param,
+ adc_read_result(pcf));
+ kfree(req);
- switch (pcf->adc_queue_mux[tail]) {
- case PCF50633_ADCC1_MUX_BATSNS_RES: /* battery voltage */
- pcf->flag_bat_voltage_read = async_adc_complete(pcf);
- break;
- case PCF50633_ADCC1_MUX_ADCIN1: /* charger type */
- pcf->charger_adc_result_raw = async_adc_complete(pcf);
- pcf->charger_type = interpret_charger_type_from_adc(
- pcf, pcf->charger_adc_result_raw);
- configure_pmu_for_charger(pcf, pcf->charger_type);
- break;
- default:
- async_adc_complete(pcf);
- break;
- }
trigger_next_adc_job_if_any(pcf);
}
if (pcfirq[2] & PCF50633_INT3_ONKEY1S) {
@@ -1271,22 +1337,17 @@ static u_int8_t battvolt_scale(u_int16_t battvolt)
u_int16_t pcf50633_battvolt(struct pcf50633_data *pcf)
{
- int count = 10;
+ int ret;
- pcf->flag_bat_voltage_read = -1;
- add_request_to_adc_queue(pcf, PCF50633_ADCC1_MUX_BATSNS_RES,
+ ret = adc_sync_read(pcf, PCF50633_ADCC1_MUX_BATSNS_RES,
PCF50633_ADCC1_AVERAGE_16);
- while ((count--) && (pcf->flag_bat_voltage_read < 0))
- msleep(1);
-
- if (count < 0) { /* timeout somehow */
- DEBUGPC("pcf50633_battvolt timeout :-(\n");
- return -1;
- }
+ if (ret < 0)
+ return ret;
- return adc_to_batt_millivolts(pcf->flag_bat_voltage_read);
+ return adc_to_batt_millivolts(ret);
}
+
EXPORT_SYMBOL_GPL(pcf50633_battvolt);
static ssize_t show_battvolt(struct device *dev, struct device_attribute *attr,
@@ -1904,6 +1965,8 @@ static ssize_t show_charger_type(struct device *dev,
{
struct i2c_client *client = to_i2c_client(dev);
struct pcf50633_data *pcf = i2c_get_clientdata(client);
+ int adc_raw_result, charger_type;
+
static const char *names_charger_type[] = {
[CHARGER_TYPE_NONE] = "none",
[CHARGER_TYPE_HOSTUSB] = "host/500mA usb",
@@ -1917,8 +1980,11 @@ static ssize_t show_charger_type(struct device *dev,
};
int mode = pcf50633_reg_read(pcf, PCF50633_REG_MBCC7) & PCF56033_MBCC7_USB_MASK;
+ adc_raw_result = adc_sync_read(pcf, PCF50633_ADCC1_MUX_ADCIN1,
+ PCF50633_ADCC1_AVERAGE_16);
+ charger_type = interpret_charger_type_from_adc(pcf, adc_raw_result);
return sprintf(buf, "%s mode %s\n",
- names_charger_type[pcf->charger_type],
+ names_charger_type[charger_type],
names_charger_modes[mode]);
}
@@ -1947,8 +2013,14 @@ static ssize_t show_charger_adc(struct device *dev,
{
struct i2c_client *client = to_i2c_client(dev);
struct pcf50633_data *pcf = i2c_get_clientdata(client);
+ int result;
+
+ result = adc_sync_read(pcf, PCF50633_ADCC1_MUX_ADCIN1,
+ PCF50633_ADCC1_AVERAGE_16);
+ if (result < 0)
+ return result;
- return sprintf(buf, "%d\n", pcf->charger_adc_result_raw);
+ return sprintf(buf, "%d\n", result);
}
static DEVICE_ATTR(charger_adc, 0444, show_charger_adc, NULL);
diff --git a/include/linux/pcf50633.h b/include/linux/pcf50633.h
index b484f06..91016f9 100644
--- a/include/linux/pcf50633.h
+++ b/include/linux/pcf50633.h
@@ -109,6 +109,14 @@ extern int
pcf50633_onoff_set(struct pcf50633_data *pcf,
enum pcf50633_regulator_id reg, int on);
+extern int
+pcf50633_adc_async_read(struct pcf50633_data *pcf, int mux, int avg,
+ void *callback_param,
+ void (*callback)(struct pcf50633_data *, void *, int));
+
+extern int
+pcf50633_adc_sync_read(struct pcf50633_data *pcf, int mux, int avg);
+
extern void
pcf50633_backlight_resume(struct pcf50633_data *pcf);
More information about the openmoko-kernel
mailing list
