On 2016-12-20 17:16, Geoff Lansberry wrote:
> From: Geoff Lansberry <geoff@xxxxxxxxx>
>
> 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.
> ---
> .../devicetree/bindings/net/nfc/trf7970a.txt | 4 ++
> drivers/nfc/trf7970a.c | 50 +++++++++++++++++-----
> 2 files changed, 43 insertions(+), 11 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
> index 32b35a0..e262ac1 100644
> --- a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
> +++ b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt
> @@ -21,6 +21,8 @@ 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
> +
You're adding an empty line here that is removed in the next patch.
>
> Example (for ARM-based BeagleBone with TRF7970A on SPI1):
>
> @@ -43,6 +45,8 @@ Example (for ARM-based BeagleBone with TRF7970A on SPI1):
> irq-status-read-quirk;
> en2-rf-quirk;
> t5t-rmb-extra-byte-quirk;
> + vdd_io_1v8;
This does not belong here, and so no need to remove in the next patch.
> + clock-frequency = <27120000>;
> status = "okay";
> };
> };
> diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c
> index 26c9dbb..4e051e9 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 = 13560000;
Use TRF7970A_13MHZ_CLOCK_FREQUENCY here?
>
> 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_27MHZ_CLOCK_FREQUENCY)) {
Two comparisons with 27MHz, missing 13MHz.
> + 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;
>
>
