diff options
| -rw-r--r-- | drivers/mfd/wm831x-auxadc.c | 254 | ||||
| -rw-r--r-- | include/linux/mfd/wm831x/core.h | 13 |
2 files changed, 188 insertions, 79 deletions
diff --git a/drivers/mfd/wm831x-auxadc.c b/drivers/mfd/wm831x-auxadc.c index 2fc9531b243..87210954a06 100644 --- a/drivers/mfd/wm831x-auxadc.c +++ b/drivers/mfd/wm831x-auxadc.c @@ -17,6 +17,7 @@ #include <linux/delay.h> #include <linux/mfd/core.h> #include <linux/slab.h> +#include <linux/list.h> #include <linux/mfd/wm831x/core.h> #include <linux/mfd/wm831x/pdata.h> @@ -25,19 +26,139 @@ #include <linux/mfd/wm831x/otp.h> #include <linux/mfd/wm831x/regulator.h> -/** - * wm831x_auxadc_read: Read a value from the WM831x AUXADC - * - * @wm831x: Device to read from. - * @input: AUXADC input to read. - */ -int wm831x_auxadc_read(struct wm831x *wm831x, enum wm831x_auxadc input) +struct wm831x_auxadc_req { + struct list_head list; + enum wm831x_auxadc input; + int val; + struct completion done; +}; + +static int wm831x_auxadc_read_irq(struct wm831x *wm831x, + enum wm831x_auxadc input) { - int ret, src, irq_masked, timeout; + struct wm831x_auxadc_req *req; + int ret; + bool ena = false; + + req = kzalloc(sizeof(*req), GFP_KERNEL); + if (!req) + return -ENOMEM; + + init_completion(&req->done); + req->input = input; + req->val = -ETIMEDOUT; + + mutex_lock(&wm831x->auxadc_lock); + + /* Enqueue the request */ + list_add(&req->list, &wm831x->auxadc_pending); + + ena = !wm831x->auxadc_active; + + if (ena) { + ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL, + WM831X_AUX_ENA, WM831X_AUX_ENA); + if (ret != 0) { + dev_err(wm831x->dev, "Failed to enable AUXADC: %d\n", + ret); + goto out; + } + } + + /* Enable the conversion if not already running */ + if (!(wm831x->auxadc_active & (1 << input))) { + ret = wm831x_set_bits(wm831x, WM831X_AUXADC_SOURCE, + 1 << input, 1 << input); + if (ret != 0) { + dev_err(wm831x->dev, + "Failed to set AUXADC source: %d\n", ret); + goto out; + } + + wm831x->auxadc_active |= 1 << input; + } + + /* We convert at the fastest rate possible */ + if (ena) { + ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL, + WM831X_AUX_CVT_ENA | + WM831X_AUX_RATE_MASK, + WM831X_AUX_CVT_ENA | + WM831X_AUX_RATE_MASK); + if (ret != 0) { + dev_err(wm831x->dev, "Failed to start AUXADC: %d\n", + ret); + goto out; + } + } + + mutex_unlock(&wm831x->auxadc_lock); + + /* Wait for an interrupt */ + wait_for_completion_timeout(&req->done, msecs_to_jiffies(500)); + + mutex_lock(&wm831x->auxadc_lock); + + list_del(&req->list); + ret = req->val; + +out: + mutex_unlock(&wm831x->auxadc_lock); + + kfree(req); + + return ret; +} + +static irqreturn_t wm831x_auxadc_irq(int irq, void *irq_data) +{ + struct wm831x *wm831x = irq_data; + struct wm831x_auxadc_req *req; + int ret, input, val; + + ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA); + if (ret < 0) { + dev_err(wm831x->dev, + "Failed to read AUXADC data: %d\n", ret); + return IRQ_NONE; + } + + input = ((ret & WM831X_AUX_DATA_SRC_MASK) + >> WM831X_AUX_DATA_SRC_SHIFT) - 1; + + if (input == 14) + input = WM831X_AUX_CAL; - /* Are we using the interrupt? */ - irq_masked = wm831x_reg_read(wm831x, WM831X_INTERRUPT_STATUS_1_MASK); - irq_masked &= WM831X_AUXADC_DATA_EINT; + val = ret & WM831X_AUX_DATA_MASK; + + mutex_lock(&wm831x->auxadc_lock); + + /* Disable this conversion, we're about to complete all users */ + wm831x_set_bits(wm831x, WM831X_AUXADC_SOURCE, + 1 << input, 0); + wm831x->auxadc_active &= ~(1 << input); + + /* Turn off the entire convertor if idle */ + if (!wm831x->auxadc_active) + wm831x_reg_write(wm831x, WM831X_AUXADC_CONTROL, 0); + + /* Wake up any threads waiting for this request */ + list_for_each_entry(req, &wm831x->auxadc_pending, list) { + if (req->input == input) { + req->val = val; + complete(&req->done); + } + } + + mutex_unlock(&wm831x->auxadc_lock); + + return IRQ_HANDLED; +} + +static int wm831x_auxadc_read_polled(struct wm831x *wm831x, + enum wm831x_auxadc input) +{ + int ret, src, timeout; mutex_lock(&wm831x->auxadc_lock); @@ -57,9 +178,6 @@ int wm831x_auxadc_read(struct wm831x *wm831x, enum wm831x_auxadc input) goto out; } - /* Clear any notification from a very late arriving interrupt */ - try_wait_for_completion(&wm831x->auxadc_done); - ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL, WM831X_AUX_CVT_ENA, WM831X_AUX_CVT_ENA); if (ret < 0) { @@ -67,59 +185,42 @@ int wm831x_auxadc_read(struct wm831x *wm831x, enum wm831x_auxadc input) goto disable; } - if (irq_masked) { - /* If we're not using interrupts then poll the - * interrupt status register */ - timeout = 5; - while (timeout) { - msleep(1); - - ret = wm831x_reg_read(wm831x, - WM831X_INTERRUPT_STATUS_1); - if (ret < 0) { - dev_err(wm831x->dev, - "ISR 1 read failed: %d\n", ret); - goto disable; - } - - /* Did it complete? */ - if (ret & WM831X_AUXADC_DATA_EINT) { - wm831x_reg_write(wm831x, - WM831X_INTERRUPT_STATUS_1, - WM831X_AUXADC_DATA_EINT); - break; - } else { - dev_err(wm831x->dev, - "AUXADC conversion timeout\n"); - ret = -EBUSY; - goto disable; - } - } + /* If we're not using interrupts then poll the + * interrupt status register */ + timeout = 5; + while (timeout) { + msleep(1); - ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA); + ret = wm831x_reg_read(wm831x, + WM831X_INTERRUPT_STATUS_1); if (ret < 0) { dev_err(wm831x->dev, - "Failed to read AUXADC data: %d\n", ret); + "ISR 1 read failed: %d\n", ret); goto disable; } - wm831x->auxadc_data = ret; - - } else { - /* If we are using interrupts then wait for the - * interrupt to complete. Use an extremely long - * timeout to handle situations with heavy load where - * the notification of the interrupt may be delayed by - * threaded IRQ handling. */ - if (!wait_for_completion_timeout(&wm831x->auxadc_done, - msecs_to_jiffies(500))) { - dev_err(wm831x->dev, "Timed out waiting for AUXADC\n"); + /* Did it complete? */ + if (ret & WM831X_AUXADC_DATA_EINT) { + wm831x_reg_write(wm831x, + WM831X_INTERRUPT_STATUS_1, + WM831X_AUXADC_DATA_EINT); + break; + } else { + dev_err(wm831x->dev, + "AUXADC conversion timeout\n"); ret = -EBUSY; goto disable; } } - src = ((wm831x->auxadc_data & WM831X_AUX_DATA_SRC_MASK) + ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA); + if (ret < 0) { + dev_err(wm831x->dev, + "Failed to read AUXADC data: %d\n", ret); + goto disable; + } + + src = ((ret & WM831X_AUX_DATA_SRC_MASK) >> WM831X_AUX_DATA_SRC_SHIFT) - 1; if (src == 14) @@ -130,7 +231,7 @@ int wm831x_auxadc_read(struct wm831x *wm831x, enum wm831x_auxadc input) src, input); ret = -EINVAL; } else { - ret = wm831x->auxadc_data & WM831X_AUX_DATA_MASK; + ret &= WM831X_AUX_DATA_MASK; } disable: @@ -139,26 +240,18 @@ out: mutex_unlock(&wm831x->auxadc_lock); return ret; } -EXPORT_SYMBOL_GPL(wm831x_auxadc_read); -static irqreturn_t wm831x_auxadc_irq(int irq, void *irq_data) +/** + * wm831x_auxadc_read: Read a value from the WM831x AUXADC + * + * @wm831x: Device to read from. + * @input: AUXADC input to read. + */ +int wm831x_auxadc_read(struct wm831x *wm831x, enum wm831x_auxadc input) { - struct wm831x *wm831x = irq_data; - int ret; - - ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA); - if (ret < 0) { - dev_err(wm831x->dev, - "Failed to read AUXADC data: %d\n", ret); - wm831x->auxadc_data = 0xffff; - } else { - wm831x->auxadc_data = ret; - } - - complete(&wm831x->auxadc_done); - - return IRQ_HANDLED; + return wm831x->auxadc_read(wm831x, input); } +EXPORT_SYMBOL_GPL(wm831x_auxadc_read); /** * wm831x_auxadc_read_uv: Read a voltage from the WM831x AUXADC @@ -185,15 +278,22 @@ void wm831x_auxadc_init(struct wm831x *wm831x) int ret; mutex_init(&wm831x->auxadc_lock); - init_completion(&wm831x->auxadc_done); + INIT_LIST_HEAD(&wm831x->auxadc_pending); + + if (wm831x->irq && wm831x->irq_base) { + wm831x->auxadc_read = wm831x_auxadc_read_irq; - if (wm831x->irq_base) { ret = request_threaded_irq(wm831x->irq_base + WM831X_IRQ_AUXADC_DATA, NULL, wm831x_auxadc_irq, 0, "auxadc", wm831x); - if (ret < 0) + if (ret < 0) { dev_err(wm831x->dev, "AUXADC IRQ request failed: %d\n", ret); + wm831x->auxadc_read = NULL; + } } + + if (!wm831x->auxadc_read) + wm831x->auxadc_read = wm831x_auxadc_read_polled; } diff --git a/include/linux/mfd/wm831x/core.h b/include/linux/mfd/wm831x/core.h index 592e4fd6ab3..9fa14cdc159 100644 --- a/include/linux/mfd/wm831x/core.h +++ b/include/linux/mfd/wm831x/core.h @@ -17,6 +17,7 @@ #include <linux/completion.h> #include <linux/interrupt.h> +#include <linux/list.h> /* * Register values. @@ -249,6 +250,12 @@ enum wm831x_parent { WM8326 = 0x8326, }; +struct wm831x; +enum wm831x_auxadc; + +typedef int (*wm831x_auxadc_read_fn)(struct wm831x *wm831x, + enum wm831x_auxadc input); + struct wm831x { struct mutex io_lock; @@ -277,8 +284,9 @@ struct wm831x { int gpio_update[WM831X_NUM_GPIO_REGS]; struct mutex auxadc_lock; - struct completion auxadc_done; - u16 auxadc_data; + struct list_head auxadc_pending; + u16 auxadc_active; + wm831x_auxadc_read_fn auxadc_read; /* The WM831x has a security key blocking access to certain * registers. The mutex is taken by the accessors for locking @@ -305,5 +313,6 @@ void wm831x_device_exit(struct wm831x *wm831x); int wm831x_device_suspend(struct wm831x *wm831x); int wm831x_irq_init(struct wm831x *wm831x, int irq); void wm831x_irq_exit(struct wm831x *wm831x); +void wm831x_auxadc_init(struct wm831x *wm831x); #endif |