Input: cyttsp - obtain regulators

The CYTTSP TMA340 chips have two supplies: VCPIN and
VDD for analog and digital voltage respectively.
Add some minimal code to obtain and enable these
regulators if need be.

Reviewed-by: Javier Martinez Canillas <javier@dowhile0.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210526230352.1433537-3-linus.walleij@linaro.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/touchscreen/cyttsp_core.c b/drivers/input/touchscreen/cyttsp_core.c
index 106dd49..d9debcd 100644 (file)
--- a/drivers/input/touchscreen/cyttsp_core.c
+++ b/drivers/input/touchscreen/cyttsp_core.c
@@ -22,6 +22,7 @@
 #include <linux/slab.h>
 #include <linux/property.h>
 #include <linux/gpio/consumer.h>
+#include <linux/regulator/consumer.h>
 
 #include "cyttsp_core.h"
 
@@ -608,6 +609,14 @@ static int cyttsp_parse_properties(struct cyttsp *ts)
        return 0;
 }
 
+static void cyttsp_disable_regulators(void *_ts)
+{
+       struct cyttsp *ts = _ts;
+
+       regulator_bulk_disable(ARRAY_SIZE(ts->regulators),
+                              ts->regulators);
+}
+
 struct cyttsp *cyttsp_probe(const struct cyttsp_bus_ops *bus_ops,
                            struct device *dev, int irq, size_t xfer_buf_size)
 {
@@ -628,6 +637,32 @@ struct cyttsp *cyttsp_probe(const struct cyttsp_bus_ops *bus_ops,
        ts->bus_ops = bus_ops;
        ts->irq = irq;
 
+       /*
+        * VCPIN is the analog voltage supply
+        * VDD is the digital voltage supply
+        */
+       ts->regulators[0].supply = "vcpin";
+       ts->regulators[1].supply = "vdd";
+       error = devm_regulator_bulk_get(dev, ARRAY_SIZE(ts->regulators),
+                                       ts->regulators);
+       if (error) {
+               dev_err(dev, "Failed to get regulators: %d\n", error);
+               return ERR_PTR(error);
+       }
+
+       error = regulator_bulk_enable(ARRAY_SIZE(ts->regulators),
+                                     ts->regulators);
+       if (error) {
+               dev_err(dev, "Cannot enable regulators: %d\n", error);
+               return ERR_PTR(error);
+       }
+
+       error = devm_add_action_or_reset(dev, cyttsp_disable_regulators, ts);
+       if (error) {
+               dev_err(dev, "failed to install chip disable handler\n");
+               return ERR_PTR(error);
+       }
+
        ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
        if (IS_ERR(ts->reset_gpio)) {
                error = PTR_ERR(ts->reset_gpio);

diff --git a/drivers/input/touchscreen/cyttsp_core.h b/drivers/input/touchscreen/cyttsp_core.h
index 9bc4fe7..8eba9d8 100644 (file)
--- a/drivers/input/touchscreen/cyttsp_core.h
+++ b/drivers/input/touchscreen/cyttsp_core.h
@@ -23,6 +23,7 @@
 #include <linux/types.h>
 #include <linux/device.h>
 #include <linux/input/cyttsp.h>
+#include <linux/regulator/consumer.h>
 
 #define CY_NUM_RETRY           16 /* max number of retries for read ops */
 
@@ -122,6 +123,7 @@ struct cyttsp {
        enum cyttsp_state state;
        bool suspended;
 
+       struct regulator_bulk_data regulators[2];
        struct gpio_desc *reset_gpio;
        bool use_hndshk;
        u8 act_dist;