diff options
| author | Geoff Lansberry <geoff@kuvee.com> | 2016-12-21 23:18:32 -0500 |
|---|---|---|
| committer | Samuel Ortiz <sameo@linux.intel.com> | 2017-04-05 11:03:47 +0200 |
| commit | 837eb4d21ecde7bde7a1fe523594fdf509055f3f (patch) | |
| tree | d0ec2d6e158ecc238c25beda6186f1c6b022d3b7 /drivers/nfc/trf7970a.c | |
| parent | 2891f2d5c13b7386331250d59920bdf8a54bfccb (diff) | |
NFC: trf7970a: add device tree option for 27MHz clock
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.
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Geoff Lansberry <geoff@kuvee.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Diffstat (limited to 'drivers/nfc/trf7970a.c')
| -rw-r--r-- | drivers/nfc/trf7970a.c | 50 |
1 files changed, 39 insertions, 11 deletions
diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c index 75079fb16f22..ecb786283ffa 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); @@ -1990,6 +2008,7 @@ 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"); @@ -2045,6 +2064,15 @@ static int trf7970a_probe(struct spi_device *spi) } } + 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; |