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NFC: trf7970a: add device tree option for 27MHz clock

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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>
This commit is contained in:
Geoff Lansberry 2016-12-21 23:18:32 -05:00 committed by Samuel Ortiz
parent 2891f2d5c1
commit 837eb4d21e
2 changed files with 41 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Documentation/devicetree/bindings/net/nfc/trf7970a.txt
View File

@ -21,6 +21,7 @@ Optional SoC Specific Properties:
- t5t-rmb-extra-byte-quirk: Specify that the trf7970a has the erratum - t5t-rmb-extra-byte-quirk: Specify that the trf7970a has the erratum
where an extra byte is returned by Read Multiple Block commands issued where an extra byte is returned by Read Multiple Block commands issued
to Type 5 tags. 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): 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; irq-status-read-quirk;
en2-rf-quirk; en2-rf-quirk;
t5t-rmb-extra-byte-quirk; t5t-rmb-extra-byte-quirk;
clock-frequency = <27120000>;
status = "okay"; status = "okay";
}; };
}; };

50
drivers/nfc/trf7970a.c
View File

@ -124,6 +124,9 @@
NFC_PROTO_ISO15693_MASK | NFC_PROTO_NFC_DEP_MASK) NFC_PROTO_ISO15693_MASK | NFC_PROTO_NFC_DEP_MASK)
#define TRF7970A_AUTOSUSPEND_DELAY 30000 /* 30 seconds */ #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 #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; 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) if (ret)
goto err_out; goto err_out;
trf->modulator_sys_clk_ctrl = 0;
ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS, ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 | TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32); 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) { switch (tech) {
case NFC_DIGITAL_RF_TECH_106A: case NFC_DIGITAL_RF_TECH_106A:
trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106; 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; trf->guard_time = TRF7970A_GUARD_TIME_NFCA;
break; break;
case NFC_DIGITAL_RF_TECH_106B: case NFC_DIGITAL_RF_TECH_106B:
trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106; 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; trf->guard_time = TRF7970A_GUARD_TIME_NFCB;
break; break;
case NFC_DIGITAL_RF_TECH_212F: case NFC_DIGITAL_RF_TECH_212F:
trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212; 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; trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
break; break;
case NFC_DIGITAL_RF_TECH_424F: case NFC_DIGITAL_RF_TECH_424F:
trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424; 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; trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
break; break;
case NFC_DIGITAL_RF_TECH_ISO15693: case NFC_DIGITAL_RF_TECH_ISO15693:
trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648; 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; trf->guard_time = TRF7970A_GUARD_TIME_15693;
break; break;
default: 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 | trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
TRF7970A_ISO_CTRL_NFC_CE | TRF7970A_ISO_CTRL_NFC_CE |
TRF7970A_ISO_CTRL_NFC_CE_14443A; 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; break;
case NFC_DIGITAL_RF_TECH_212F: case NFC_DIGITAL_RF_TECH_212F:
trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE | trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
TRF7970A_ISO_CTRL_NFC_NFCF_212; 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; break;
case NFC_DIGITAL_RF_TECH_424F: case NFC_DIGITAL_RF_TECH_424F:
trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE | trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
TRF7970A_ISO_CTRL_NFC_NFCF_424; 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; break;
default: default:
dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech); 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 device_node *np = spi->dev.of_node;
struct trf7970a *trf; struct trf7970a *trf;
int uvolts, autosuspend_delay, ret; int uvolts, autosuspend_delay, ret;
u32 clk_freq = TRF7970A_13MHZ_CLOCK_FREQUENCY;
if (!np) { if (!np) {
dev_err(&spi->dev, "No Device Tree entry\n"); 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")) if (of_property_read_bool(np, "en2-rf-quirk"))
trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW; trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;