Thanks Mark.   Should I resubmit patches with the requested edits today, or wait a bit for more comments?  What is the desired etiquette?

On Dec 20, 2016, at 9:23 PM, Mark Greer [off-list ref] wrote:

quoted

On Tue, Dec 20, 2016 at 11:16:31AM -0500, Geoff Lansberry wrote:
From: Geoff Lansberry <redacted>

The TRF7970A has configuration options for supporting hardware designs
with 1.8 Volt or 3.3 Volt IO.   This commit adds a device tree option,
using a fixed regulator binding, for setting the io voltage to match
the hardware configuration. If no option is supplied it defaults to
3.3 volt configuration.

Sign-off ??  Same comment for you other patches.

<time passes>

Okay I see you have it at the end of the patch.  It should be here.
'git commit -s' is your friend.

quoted

---
.../devicetree/bindings/net/nfc/trf7970a.txt       |  4 ++--
drivers/nfc/trf7970a.c                             | 28 +++++++++++++++++++++-
2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
index e262ac1..b5777d8 100644
--- a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
+++ b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt

@@ -21,9 +21,9 @@ Optional SoC Specific Properties:
- t5t-rmb-extra-byte-quirk: Specify that the trf7970a has the erratum
  where an extra byte is returned by Read Multiple Block commands issued
  to Type 5 tags.
+- vdd-io-supply: Regulator specifying voltage for vdd-io
- clock-frequency: Set to specify that the input frequency to the trf7970a is 13560000Hz or 27120000Hz

-

Example (for ARM-based BeagleBone with TRF7970A on SPI1):

&spi1 {

@@ -41,11 +41,11 @@ Example (for ARM-based BeagleBone with TRF7970A on SPI1):
                 <&gpio2 5 GPIO_ACTIVE_LOW>;
       vin-supply = <&ldo3_reg>;
       vin-voltage-override = <5000000>;
+        vdd-io-supply = <&ldo2_reg>;
       autosuspend-delay = <30000>;
       irq-status-read-quirk;
       en2-rf-quirk;
       t5t-rmb-extra-byte-quirk;
-        vdd_io_1v8;

It was already mentioned but this shouldn't have been added in the
previous patch so it shouldn't be here now.

quoted

       clock-frequency = <27120000>;
       status = "okay";
   };

diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c
index 4e051e9..8a88195 100644
--- a/drivers/nfc/trf7970a.c
+++ b/drivers/nfc/trf7970a.c

quoted

@@ -2062,6 +2068,7 @@ static int trf7970a_probe(struct spi_device *spi)
       return ret;
   }

+

Please don't add an extra blank line.

quoted

   of_property_read_u32(np, "clock-frequency", &clk_freq);
   if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) ||
       (clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY)) {

@@ -2105,6 +2112,25 @@ static int trf7970a_probe(struct spi_device *spi)
   if (uvolts > 4000000)
       trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;

+    trf->regulator = devm_regulator_get(&spi->dev, "vdd-io");
+    if (IS_ERR(trf->regulator)) {
+        ret = PTR_ERR(trf->regulator);
+        dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret);
+        goto err_destroy_lock;
+    }
+
+    ret = regulator_enable(trf->regulator);
+    if (ret) {
+        dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret);
+        goto err_destroy_lock;
+    }
+
+

Please don't add an extra blank line.

quoted

+    if (regulator_get_voltage(trf->regulator) == 1800000) {
+        trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW;
+        dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n");
+    }
+
   trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
           TRF7970A_SUPPORTED_PROTOCOLS,
           NFC_DIGITAL_DRV_CAPS_IN_CRC |
-- 
Signed-off-by: Geoff Lansberry <redacted>

Your 'Signed-off-by:' goes at the end of the commit description not here.

Overall, I think you did the right thing (unless someone disagrees).
Just some minor issues.

Mark
--