summaryrefslogtreecommitdiffstats
path: root/drivers/nfc
diff options
context:
space:
mode:
authorGeoff Lansberry <geoff@kuvee.com>2016-12-21 23:18:32 -0500
committerSamuel Ortiz <sameo@linux.intel.com>2017-04-05 11:03:47 +0200
commit837eb4d21ecde7bde7a1fe523594fdf509055f3f (patch)
treed0ec2d6e158ecc238c25beda6186f1c6b022d3b7 /drivers/nfc
parent2891f2d5c13b7386331250d59920bdf8a54bfccb (diff)
downloadlinux-837eb4d21ecde7bde7a1fe523594fdf509055f3f.tar.bz2
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')
-rw-r--r--drivers/nfc/trf7970a.c50
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;