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[PATCH v3 1/3] NFC: trf7970a: add device tree option for 27MHz clock

Started byGeoff Lansberry <geoff@kuvee.com>
First post2016-12-22 05:20 +0100
Last post2016-12-23 00:10 +0100
Articles 4 — 2 participants

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  [PATCH v3 1/3] NFC: trf7970a: add device tree option for 27MHz clock Geoff Lansberry <geoff@kuvee.com> - 2016-12-22 05:20 +0100
    [PATCH v3 2/3] NFC: trf7970a: Add device tree option of 1.8 Volt IO voltage Geoff Lansberry <geoff@kuvee.com> - 2016-12-22 05:20 +0100
      Re: [PATCH v3 2/3] NFC: trf7970a: Add device tree option of 1.8 Volt  IO voltage Rob Herring <robh@kernel.org> - 2016-12-23 00:10 +0100
    Re: [PATCH v3 1/3] NFC: trf7970a: add device tree option for 27MHz  clock Rob Herring <robh@kernel.org> - 2016-12-23 00:10 +0100

#1546148 — [PATCH v3 1/3] NFC: trf7970a: add device tree option for 27MHz clock

FromGeoff Lansberry <geoff@kuvee.com>
Date2016-12-22 05:20 +0100
Subject[PATCH v3 1/3] NFC: trf7970a: add device tree option for 27MHz clock
Message-ID<sR31f-4py-1@gated-at.bofh.it>
The TRF7970A has configuration options to support hardware designs
which use a 27.12MHz clock. This commit adds a device tree option
'clock-frequency' to support configuring the this chip for default
13.56MHz clock or the optional 27.12MHz clock.

Signed-off-by: Geoff Lansberry <geoff@kuvee.com>
---
 .../devicetree/bindings/net/nfc/trf7970a.txt       |  2 +
 drivers/nfc/trf7970a.c                             | 50 +++++++++++++++++-----
 2 files changed, 41 insertions(+), 11 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
index 32b35a0..8b01fc81 100644
--- a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
+++ b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
@@ -21,6 +21,7 @@ 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.
+- 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):
 
@@ -43,6 +44,7 @@ Example (for ARM-based BeagleBone with TRF7970A on SPI1):
 		irq-status-read-quirk;
 		en2-rf-quirk;
 		t5t-rmb-extra-byte-quirk;
+		clock-frequency = <27120000>;
 		status = "okay";
 	};
 };
diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c
index 26c9dbb..b1cd4ef 100644
--- a/drivers/nfc/trf7970a.c
+++ b/drivers/nfc/trf7970a.c
@@ -124,6 +124,9 @@
 		 NFC_PROTO_ISO15693_MASK | NFC_PROTO_NFC_DEP_MASK)
 
 #define TRF7970A_AUTOSUSPEND_DELAY		30000 /* 30 seconds */
+#define TRF7970A_13MHZ_CLOCK_FREQUENCY		13560000
+#define TRF7970A_27MHZ_CLOCK_FREQUENCY		27120000
+
 
 #define TRF7970A_RX_SKB_ALLOC_SIZE		256
 
@@ -1056,12 +1059,11 @@ static int trf7970a_init(struct trf7970a *trf)
 
 	trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
 
-	ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL, 0);
+	ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
+			trf->modulator_sys_clk_ctrl);
 	if (ret)
 		goto err_out;
 
-	trf->modulator_sys_clk_ctrl = 0;
-
 	ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
 			TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
 			TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
@@ -1181,27 +1183,37 @@ static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech)
 	switch (tech) {
 	case NFC_DIGITAL_RF_TECH_106A:
 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106;
-		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_OOK;
+		trf->modulator_sys_clk_ctrl =
+			(trf->modulator_sys_clk_ctrl & 0xf8) |
+			TRF7970A_MODULATOR_DEPTH_OOK;
 		trf->guard_time = TRF7970A_GUARD_TIME_NFCA;
 		break;
 	case NFC_DIGITAL_RF_TECH_106B:
 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106;
-		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
+		trf->modulator_sys_clk_ctrl =
+			(trf->modulator_sys_clk_ctrl & 0xf8) |
+			TRF7970A_MODULATOR_DEPTH_ASK10;
 		trf->guard_time = TRF7970A_GUARD_TIME_NFCB;
 		break;
 	case NFC_DIGITAL_RF_TECH_212F:
 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212;
-		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
+		trf->modulator_sys_clk_ctrl =
+			(trf->modulator_sys_clk_ctrl & 0xf8) |
+			TRF7970A_MODULATOR_DEPTH_ASK10;
 		trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
 		break;
 	case NFC_DIGITAL_RF_TECH_424F:
 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424;
-		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
+		trf->modulator_sys_clk_ctrl =
+			(trf->modulator_sys_clk_ctrl & 0xf8) |
+			TRF7970A_MODULATOR_DEPTH_ASK10;
 		trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
 		break;
 	case NFC_DIGITAL_RF_TECH_ISO15693:
 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
-		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_OOK;
+		trf->modulator_sys_clk_ctrl =
+			(trf->modulator_sys_clk_ctrl & 0xf8) |
+			TRF7970A_MODULATOR_DEPTH_OOK;
 		trf->guard_time = TRF7970A_GUARD_TIME_15693;
 		break;
 	default:
@@ -1571,17 +1583,23 @@ static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
 			TRF7970A_ISO_CTRL_NFC_CE |
 			TRF7970A_ISO_CTRL_NFC_CE_14443A;
-		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_OOK;
+		trf->modulator_sys_clk_ctrl =
+			(trf->modulator_sys_clk_ctrl & 0xf8) |
+			TRF7970A_MODULATOR_DEPTH_OOK;
 		break;
 	case NFC_DIGITAL_RF_TECH_212F:
 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
 			TRF7970A_ISO_CTRL_NFC_NFCF_212;
-		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
+		trf->modulator_sys_clk_ctrl =
+			(trf->modulator_sys_clk_ctrl & 0xf8) |
+			TRF7970A_MODULATOR_DEPTH_ASK10;
 		break;
 	case NFC_DIGITAL_RF_TECH_424F:
 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
 			TRF7970A_ISO_CTRL_NFC_NFCF_424;
-		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
+		trf->modulator_sys_clk_ctrl =
+			(trf->modulator_sys_clk_ctrl & 0xf8) |
+			TRF7970A_MODULATOR_DEPTH_ASK10;
 		break;
 	default:
 		dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
@@ -1987,6 +2005,7 @@ static int trf7970a_probe(struct spi_device *spi)
 	struct device_node *np = spi->dev.of_node;
 	struct trf7970a *trf;
 	int uvolts, autosuspend_delay, ret;
+	u32 clk_freq = TRF7970A_13MHZ_CLOCK_FREQUENCY;
 
 	if (!np) {
 		dev_err(&spi->dev, "No Device Tree entry\n");
@@ -2043,6 +2062,15 @@ static int trf7970a_probe(struct spi_device *spi)
 		return ret;
 	}
 
+	of_property_read_u32(np, "clock-frequency", &clk_freq);
+	if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) ||
+		(clk_freq != TRF7970A_13MHZ_CLOCK_FREQUENCY)) {
+		dev_err(trf->dev,
+			"clock-frequency (%u Hz) unsupported\n",
+			clk_freq);
+		return -EINVAL;
+	}
+
 	if (of_property_read_bool(np, "en2-rf-quirk"))
 		trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
 
-- 
2.7.4

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#1546154 — [PATCH v3 2/3] NFC: trf7970a: Add device tree option of 1.8 Volt IO voltage

FromGeoff Lansberry <geoff@kuvee.com>
Date2016-12-22 05:20 +0100
Subject[PATCH v3 2/3] NFC: trf7970a: Add device tree option of 1.8 Volt IO voltage
Message-ID<sR31f-4py-15@gated-at.bofh.it>
In reply to#1546148
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.

Signed-off-by: Geoff Lansberry <geoff@kuvee.com>
---
 .../devicetree/bindings/net/nfc/trf7970a.txt       |  2 ++
 drivers/nfc/trf7970a.c                             | 26 +++++++++++++++++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
index 8b01fc81..b5777d8 100644
--- a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
+++ b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
@@ -21,6 +21,7 @@ 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):
@@ -40,6 +41,7 @@ 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;
diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c
index b1cd4ef..e3c72c6 100644
--- a/drivers/nfc/trf7970a.c
+++ b/drivers/nfc/trf7970a.c
@@ -444,6 +444,7 @@ struct trf7970a {
 	u8				iso_ctrl_tech;
 	u8				modulator_sys_clk_ctrl;
 	u8				special_fcn_reg1;
+	u8				io_ctrl;
 	unsigned int			guard_time;
 	int				technology;
 	int				framing;
@@ -1051,6 +1052,11 @@ static int trf7970a_init(struct trf7970a *trf)
 	if (ret)
 		goto err_out;
 
+	ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
+			trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
+	if (ret)
+		goto err_out;
+
 	ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
 	if (ret)
 		goto err_out;
@@ -1767,7 +1773,7 @@ static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
 		goto out_err;
 
 	ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
-			TRF7970A_REG_IO_CTRL_VRS(0x1));
+			trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
 	if (ret)
 		goto out_err;
 
@@ -2105,6 +2111,24 @@ 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;
+	}
+
+	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 |
-- 
2.7.4

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#1546642 — Re: [PATCH v3 2/3] NFC: trf7970a: Add device tree option of 1.8 Volt IO voltage

FromRob Herring <robh@kernel.org>
Date2016-12-23 00:10 +0100
SubjectRe: [PATCH v3 2/3] NFC: trf7970a: Add device tree option of 1.8 Volt IO voltage
Message-ID<sRkEO-7kw-31@gated-at.bofh.it>
In reply to#1546154
On Wed, Dec 21, 2016 at 11:18:33PM -0500, Geoff Lansberry wrote:
> 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.
> 
> Signed-off-by: Geoff Lansberry <geoff@kuvee.com>
> ---
>  .../devicetree/bindings/net/nfc/trf7970a.txt       |  2 ++

Acked-by: Rob Herring <robh@kernel.org>

>  drivers/nfc/trf7970a.c                             | 26 +++++++++++++++++++++-
>  2 files changed, 27 insertions(+), 1 deletion(-)

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#1546641 — Re: [PATCH v3 1/3] NFC: trf7970a: add device tree option for 27MHz clock

FromRob Herring <robh@kernel.org>
Date2016-12-23 00:10 +0100
SubjectRe: [PATCH v3 1/3] NFC: trf7970a: add device tree option for 27MHz clock
Message-ID<sRkEN-7kw-7@gated-at.bofh.it>
In reply to#1546148
On Wed, Dec 21, 2016 at 11:18:32PM -0500, Geoff Lansberry wrote:
> The TRF7970A has configuration options to support hardware designs
> which use a 27.12MHz clock. This commit adds a device tree option
> 'clock-frequency' to support configuring the this chip for default
> 13.56MHz clock or the optional 27.12MHz clock.
> 
> Signed-off-by: Geoff Lansberry <geoff@kuvee.com>
> ---
>  .../devicetree/bindings/net/nfc/trf7970a.txt       |  2 +

Acked-by: Rob Herring <robh@kernel.org>

>  drivers/nfc/trf7970a.c                             | 50 +++++++++++++++++-----
>  2 files changed, 41 insertions(+), 11 deletions(-)

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