On Mon, Apr 18, 2016 at 8:07 PM, Julian Calaby
<julian.calaby@xxxxxxxxx <mailto:julian.calaby@xxxxxxxxx>> wrote:
Hi Geoff,
On Tue, Apr 19, 2016 at 5:48 AM, Geoff Lansberry <geoff@xxxxxxxxx
<mailto:geoff@xxxxxxxxx>> wrote:
> Signed-off-by: Geoff Lansberry <geoff@xxxxxxxxx
<mailto:geoff@xxxxxxxxx>>
Can't you just use the cs-gpios property? This should require no
driver changes.
This is described here:
https://www.kernel.org/doc/Documentation/devicetree/bindings/spi/spi-bus.txt
Thanks,
Julian Calaby
> ---
> .../devicetree/bindings/net/nfc/trf7970a.txt | 2 ++
> drivers/nfc/trf7970a.c | 33 ++++++++++++++++++++--
> 2 files changed, 33 insertions(+), 2 deletions(-)
>
> diff --git
a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
> index 32b35a0..09c5056 100644
> --- a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
> +++ b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
> @@ -7,6 +7,7 @@ Required properties:
> - interrupts: A single interrupt specifier.
> - ti,enable-gpios: Two GPIO entries used for 'EN' and 'EN2'
pins on the
> TRF7970A.
> +- ti,ss-gpio: GPIO entry used for active low SS (spi slave
select) on the TRF7970A
> - vin-supply: Regulator for supply voltage to VIN pin
>
> Optional SoC Specific Properties:
> @@ -37,6 +38,7 @@ Example (for ARM-based BeagleBone with
TRF7970A on SPI1):
> interrupts = <14 0>;
> ti,enable-gpios = <&gpio2 2 GPIO_ACTIVE_LOW>,
> <&gpio2 5 GPIO_ACTIVE_LOW>;
> + ti,ss-gpio = <&gpio2 4 GPIO_ACTIVE_HIGH>;
> vin-supply = <&ldo3_reg>;
> vin-voltage-override = <5000000>;
> autosuspend-delay = <30000>;
> diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c
> index 10842b7..2c3530a 100644
> --- a/drivers/nfc/trf7970a.c
> +++ b/drivers/nfc/trf7970a.c
> @@ -450,6 +450,7 @@ struct trf7970a {
> bool adjust_resp_len;
> int en2_gpio;
> int en_gpio;
> + int ss_gpio;
> struct mutex lock;
> unsigned int timeout;
> bool ignore_timeout;
> @@ -462,9 +463,11 @@ static int trf7970a_cmd(struct trf7970a
*trf, u8 opcode)
> u8 cmd = TRF7970A_CMD_BIT_CTRL |
TRF7970A_CMD_BIT_OPCODE(opcode);
> int ret;
>
> + gpio_set_value(trf->ss_gpio, 0);
> dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
>
> ret = spi_write(trf->spi, &cmd, 1);
> + gpio_set_value(trf->ss_gpio, 1);
> if (ret)
> dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n",
__func__, cmd,
> ret);
> @@ -476,7 +479,9 @@ static int trf7970a_read(struct trf7970a
*trf, u8 reg, u8 *val)
> u8 addr = TRF7970A_CMD_BIT_RW | reg;
> int ret;
>
> + gpio_set_value(trf->ss_gpio, 0);
> ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
> + gpio_set_value(trf->ss_gpio, 1);
> if (ret)
> dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n",
__func__, addr,
> ret);
> @@ -493,6 +498,7 @@ static int trf7970a_read_cont(struct
trf7970a *trf, u8 reg, u8 *buf, size_t len)
> struct spi_message m;
> int ret;
>
> + gpio_set_value(trf->ss_gpio, 0);
> dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
>
> spi_message_init(&m);
> @@ -508,6 +514,7 @@ static int trf7970a_read_cont(struct
trf7970a *trf, u8 reg, u8 *buf, size_t len)
> spi_message_add_tail(&t[1], &m);
>
> ret = spi_sync(trf->spi, &m);
> + gpio_set_value(trf->ss_gpio, 1);
> if (ret)
> dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n",
__func__, addr,
> ret);
> @@ -519,9 +526,11 @@ static int trf7970a_write(struct trf7970a
*trf, u8 reg, u8 val)
> u8 buf[2] = { reg, val };
> int ret;
>
> + gpio_set_value(trf->ss_gpio, 0);
> dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
>
> ret = spi_write(trf->spi, buf, 2);
> + gpio_set_value(trf->ss_gpio, 1);
> if (ret)
> dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret:
%d\n", __func__,
> buf[0], buf[1], ret);
> @@ -535,6 +544,7 @@ static int trf7970a_read_irqstatus(struct
trf7970a *trf, u8 *status)
> u8 buf[2];
> u8 addr;
>
> + gpio_set_value(trf->ss_gpio, 0);
> addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
>
> if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ) {
> @@ -544,6 +554,7 @@ static int trf7970a_read_irqstatus(struct
trf7970a *trf, u8 *status)
> ret = spi_write_then_read(trf->spi, &addr, 1,
buf, 1);
> }
>
> + gpio_set_value(trf->ss_gpio, 1);
> if (ret)
> dev_err(trf->dev, "%s - irqstatus: Status read
failed: %d\n",
> __func__, ret);
> @@ -559,6 +570,7 @@ static int trf7970a_read_target_proto(struct
trf7970a *trf, u8 *target_proto)
> u8 buf[2];
> u8 addr;
>
> + gpio_set_value(trf->ss_gpio, 0);
> addr = TRF79070A_NFC_TARGET_PROTOCOL | TRF7970A_CMD_BIT_RW |
> TRF7970A_CMD_BIT_CONTINUOUS;
>
> @@ -569,6 +581,7 @@ static int trf7970a_read_target_proto(struct
trf7970a *trf, u8 *target_proto)
> else
> *target_proto = buf[0];
>
> + gpio_set_value(trf->ss_gpio, 1);
> return ret;
> }
>
> @@ -663,6 +676,7 @@ static int trf7970a_transmit(struct trf7970a
*trf, struct sk_buff *skb,
> print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
> 16, 1, skb->data, len, false);
>
> + gpio_set_value(trf->ss_gpio, 0);
> spi_message_init(&m);
>
> memset(&t, 0, sizeof(t));
> @@ -679,7 +693,7 @@ static int trf7970a_transmit(struct trf7970a
*trf, struct sk_buff *skb,
> if (ret) {
> dev_err(trf->dev, "%s - Can't send tx data:
%d\n", __func__,
> ret);
> - return ret;
> + goto out_err;
> }
>
> skb_pull(skb, len);
> @@ -706,7 +720,9 @@ static int trf7970a_transmit(struct trf7970a
*trf, struct sk_buff *skb,
>
> schedule_delayed_work(&trf->timeout_work,
msecs_to_jiffies(timeout));
>
> - return 0;
> +out_err:
> + gpio_set_value(trf->ss_gpio, 1);
> + return ret;
> }
>
> static void trf7970a_fill_fifo(struct trf7970a *trf)
> @@ -2039,6 +2055,19 @@ static int trf7970a_probe(struct
spi_device *spi)
> return ret;
> }
>
> + trf->ss_gpio = of_get_named_gpio(np, "ti,ss-gpio", 0);
> + if (!gpio_is_valid(trf->ss_gpio)) {
> + dev_err(trf->dev, "No SS GPIO property\n");
> + return trf->ss_gpio;
> + }
> +
> + ret = devm_gpio_request_one(trf->dev, trf->ss_gpio,
> + GPIOF_DIR_OUT | GPIOF_INIT_HIGH,
"trf7970a SS");
> + if (ret) {
> + dev_err(trf->dev, "Can't request SS GPIO: %d\n",
ret);
> + return ret;
> + }
> +
> if (of_property_read_bool(np, "en2-rf-quirk"))
> trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
>
> --
> 1.9.1
>
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--
Julian Calaby
Email: julian.calaby@xxxxxxxxx <mailto:julian.calaby@xxxxxxxxx>
Profile: http://www.google.com/profiles/julian.calaby/
--
Geoff Lansberry
Engineering Guy
Kuvée, Inc
125 Kingston St., 3rd Floor
Boston, MA 02111
1-617-290-1118 (m)
geoff.lansberry (skype)
http://www.kuvee.com
<http://www.kuvee.com>
