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Diffstat (limited to 'drivers/nfc/trf7970a.c')
-rw-r--r--drivers/nfc/trf7970a.c178
1 files changed, 119 insertions, 59 deletions
diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c
index eee5cc1a9220..d17c701c7888 100644
--- a/drivers/nfc/trf7970a.c
+++ b/drivers/nfc/trf7970a.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* TI TRF7970a RFID/NFC Transceiver Driver
*
@@ -6,10 +7,6 @@
* Author: Erick Macias <emacias@ti.com>
* Author: Felipe Balbi <balbi@ti.com>
* Author: Mark A. Greer <mgreer@animalcreek.com>
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 of
- * the License as published by the Free Software Foundation.
*/
#include <linux/module.h>
@@ -172,7 +169,7 @@
/* Bits determining whether its a direct command or register R/W,
* whether to use a continuous SPI transaction or not, and the actual
- * direct cmd opcode or regster address.
+ * direct cmd opcode or register address.
*/
#define TRF7970A_CMD_BIT_CTRL BIT(7)
#define TRF7970A_CMD_BIT_RW BIT(6)
@@ -275,12 +272,18 @@
#define TRF7970A_MODULATOR_EN_OOK BIT(6)
#define TRF7970A_MODULATOR_27MHZ BIT(7)
+#define TRF7970A_RX_GAIN_REDUCTION_MAX_DB 15
+#define TRF7970A_RX_GAIN_REDUCTION_DB_PER_LSB 5
#define TRF7970A_RX_SPECIAL_SETTINGS_NO_LIM BIT(0)
#define TRF7970A_RX_SPECIAL_SETTINGS_AGCR BIT(1)
-#define TRF7970A_RX_SPECIAL_SETTINGS_GD_0DB (0x0 << 2)
-#define TRF7970A_RX_SPECIAL_SETTINGS_GD_5DB (0x1 << 2)
-#define TRF7970A_RX_SPECIAL_SETTINGS_GD_10DB (0x2 << 2)
-#define TRF7970A_RX_SPECIAL_SETTINGS_GD_15DB (0x3 << 2)
+#define TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT 2
+#define TRF7970A_RX_SPECIAL_SETTINGS_GD_MAX (0x3)
+#define TRF7970A_RX_SPECIAL_SETTINGS_GD_MASK (TRF7970A_RX_SPECIAL_SETTINGS_GD_MAX << \
+ TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT)
+#define TRF7970A_RX_SPECIAL_SETTINGS_GD_0DB (0x0 << TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT)
+#define TRF7970A_RX_SPECIAL_SETTINGS_GD_5DB (0x1 << TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT)
+#define TRF7970A_RX_SPECIAL_SETTINGS_GD_10DB (0x2 << TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT)
+#define TRF7970A_RX_SPECIAL_SETTINGS_GD_15DB (0x3 << TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT)
#define TRF7970A_RX_SPECIAL_SETTINGS_HBT BIT(4)
#define TRF7970A_RX_SPECIAL_SETTINGS_M848 BIT(5)
#define TRF7970A_RX_SPECIAL_SETTINGS_C424 BIT(6)
@@ -427,7 +430,8 @@ struct trf7970a {
enum trf7970a_state state;
struct device *dev;
struct spi_device *spi;
- struct regulator *regulator;
+ struct regulator *vin_regulator;
+ struct regulator *vddio_regulator;
struct nfc_digital_dev *ddev;
u32 quirks;
bool is_initiator;
@@ -454,6 +458,8 @@ struct trf7970a {
unsigned int timeout;
bool ignore_timeout;
struct delayed_work timeout_work;
+ u8 rx_gain_reduction;
+ bool custom_rx_gain_reduction;
};
static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
@@ -553,6 +559,41 @@ static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
return ret;
}
+static int trf7970a_update_rx_gain_reduction(struct trf7970a *trf)
+{
+ int ret = 0;
+ u8 reg;
+
+ if (!trf->custom_rx_gain_reduction)
+ return 0;
+
+ ret = trf7970a_read(trf, TRF7970A_RX_SPECIAL_SETTINGS, &reg);
+ if (ret)
+ return ret;
+ reg &= ~(TRF7970A_RX_SPECIAL_SETTINGS_GD_MASK);
+ reg |= trf->rx_gain_reduction;
+
+ ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS, reg);
+
+ return ret;
+}
+
+static int trf7970a_update_iso_ctrl_register(struct trf7970a *trf, u8 iso_ctrl)
+{
+ int ret;
+
+ ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
+ if (ret)
+ return ret;
+ /*
+ * Every time the ISO_CTRL register is written, the RX special setting register is reset by
+ * the chip. When a custom gain reguduction is required, it should be rewritten now.
+ */
+ ret = trf7970a_update_rx_gain_reduction(trf);
+
+ return ret;
+}
+
static int trf7970a_read_target_proto(struct trf7970a *trf, u8 *target_proto)
{
int ret;
@@ -646,7 +687,7 @@ static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
}
static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
- unsigned int len, u8 *prefix,
+ unsigned int len, const u8 *prefix,
unsigned int prefix_len)
{
struct spi_transfer t[2];
@@ -932,8 +973,7 @@ static irqreturn_t trf7970a_irq(int irq, void *dev_id)
}
if (iso_ctrl != trf->iso_ctrl) {
- ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
- iso_ctrl);
+ ret = trf7970a_update_iso_ctrl_register(trf, iso_ctrl);
if (ret)
goto err_unlock_exit;
@@ -1037,6 +1077,11 @@ static int trf7970a_init(struct trf7970a *trf)
if (ret)
goto err_out;
+ /* Set the gain reduction after soft init */
+ ret = trf7970a_update_rx_gain_reduction(trf);
+ if (ret)
+ goto err_out;
+
ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
if (ret)
goto err_out;
@@ -1156,7 +1201,7 @@ static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
dev_err(trf->dev, "%s - Invalid request: %d %d\n",
__func__, trf->state, on);
ret = -EINVAL;
- /* FALLTHROUGH */
+ fallthrough;
case TRF7970A_ST_IDLE:
case TRF7970A_ST_IDLE_RX_BLOCKED:
case TRF7970A_ST_WAIT_FOR_RX_DATA:
@@ -1311,7 +1356,7 @@ static int trf7970a_in_config_framing(struct trf7970a *trf, int framing)
}
if (iso_ctrl != trf->iso_ctrl) {
- ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
+ ret = trf7970a_update_iso_ctrl_register(trf, iso_ctrl);
if (ret)
return ret;
@@ -1385,15 +1430,15 @@ static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
case ISO15693_CMD_WRITE_DSFID:
case ISO15693_CMD_LOCK_DSFID:
return 1;
- break;
default:
return 0;
}
}
-static int trf7970a_per_cmd_config(struct trf7970a *trf, struct sk_buff *skb)
+static int trf7970a_per_cmd_config(struct trf7970a *trf,
+ const struct sk_buff *skb)
{
- u8 *req = skb->data;
+ const u8 *req = skb->data;
u8 special_fcn_reg1, iso_ctrl;
int ret;
@@ -1443,7 +1488,7 @@ static int trf7970a_per_cmd_config(struct trf7970a *trf, struct sk_buff *skb)
}
if (iso_ctrl != trf->iso_ctrl) {
- ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
+ ret = trf7970a_update_iso_ctrl_register(trf, iso_ctrl);
if (ret)
return ret;
@@ -1607,8 +1652,7 @@ static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
*/
if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) &&
(trf->iso_ctrl_tech != trf->iso_ctrl)) {
- ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
- trf->iso_ctrl_tech);
+ ret = trf7970a_update_iso_ctrl_register(trf, trf->iso_ctrl_tech);
trf->iso_ctrl = trf->iso_ctrl_tech;
}
@@ -1656,7 +1700,7 @@ static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing)
trf->framing = framing;
if (iso_ctrl != trf->iso_ctrl) {
- ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
+ ret = trf7970a_update_iso_ctrl_register(trf, iso_ctrl);
if (ret)
return ret;
@@ -1757,6 +1801,10 @@ static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
if (ret)
goto out_err;
+ ret = trf7970a_update_rx_gain_reduction(trf);
+ if (ret)
+ goto out_err;
+
ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
if (ret)
@@ -1795,7 +1843,7 @@ out_err:
static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
nfc_digital_cmd_complete_t cb, void *arg)
{
- struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
+ const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
dev_dbg(trf->dev, "Listen - state: %d, timeout: %d ms\n",
trf->state, timeout);
@@ -1807,7 +1855,7 @@ static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
u16 timeout, nfc_digital_cmd_complete_t cb,
void *arg)
{
- struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
+ const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
int ret;
dev_dbg(trf->dev, "Listen MD - state: %d, timeout: %d ms\n",
@@ -1828,7 +1876,7 @@ static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
static int trf7970a_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
{
- struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
+ const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
dev_dbg(trf->dev, "Get RF Tech - state: %d, rf_tech: %d\n",
trf->state, trf->md_rf_tech);
@@ -1865,7 +1913,7 @@ static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
mutex_unlock(&trf->lock);
}
-static struct nfc_digital_ops trf7970a_nfc_ops = {
+static const struct nfc_digital_ops trf7970a_nfc_ops = {
.in_configure_hw = trf7970a_in_configure_hw,
.in_send_cmd = trf7970a_send_cmd,
.tg_configure_hw = trf7970a_tg_configure_hw,
@@ -1886,7 +1934,7 @@ static int trf7970a_power_up(struct trf7970a *trf)
if (trf->state != TRF7970A_ST_PWR_OFF)
return 0;
- ret = regulator_enable(trf->regulator);
+ ret = regulator_enable(trf->vin_regulator);
if (ret) {
dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
return ret;
@@ -1929,7 +1977,7 @@ static int trf7970a_power_down(struct trf7970a *trf)
if (trf->en2_gpiod && !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW))
gpiod_set_value_cansleep(trf->en2_gpiod, 0);
- ret = regulator_disable(trf->regulator);
+ ret = regulator_disable(trf->vin_regulator);
if (ret)
dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
ret);
@@ -1947,6 +1995,10 @@ static int trf7970a_startup(struct trf7970a *trf)
if (ret)
return ret;
+ ret = trf7970a_update_rx_gain_reduction(trf);
+ if (ret)
+ return ret;
+
pm_runtime_set_active(trf->dev);
pm_runtime_enable(trf->dev);
pm_runtime_mark_last_busy(trf->dev);
@@ -1963,7 +2015,7 @@ static void trf7970a_shutdown(struct trf7970a *trf)
case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
case TRF7970A_ST_LISTENING:
trf7970a_send_err_upstream(trf, -ECANCELED);
- /* FALLTHROUGH */
+ fallthrough;
case TRF7970A_ST_IDLE:
case TRF7970A_ST_IDLE_RX_BLOCKED:
trf7970a_switch_rf_off(trf);
@@ -1978,7 +2030,7 @@ static void trf7970a_shutdown(struct trf7970a *trf)
trf7970a_power_down(trf);
}
-static int trf7970a_get_autosuspend_delay(struct device_node *np)
+static int trf7970a_get_autosuspend_delay(const struct device_node *np)
{
int autosuspend_delay, ret;
@@ -1991,10 +2043,11 @@ static int trf7970a_get_autosuspend_delay(struct device_node *np)
static int trf7970a_probe(struct spi_device *spi)
{
- struct device_node *np = spi->dev.of_node;
+ const struct device_node *np = spi->dev.of_node;
struct trf7970a *trf;
int uvolts, autosuspend_delay, ret;
u32 clk_freq = TRF7970A_13MHZ_CLOCK_FREQUENCY;
+ u32 rx_gain_reduction_db;
if (!np) {
dev_err(&spi->dev, "No Device Tree entry\n");
@@ -2056,6 +2109,20 @@ static int trf7970a_probe(struct spi_device *spi)
trf->modulator_sys_clk_ctrl = 0;
}
+ if (of_property_read_u32(np, "ti,rx-gain-reduction-db", &rx_gain_reduction_db) == 0) {
+ if (rx_gain_reduction_db > TRF7970A_RX_GAIN_REDUCTION_MAX_DB) {
+ dev_warn(trf->dev, "RX Gain reduction too high. Ignored\n");
+ } else if ((rx_gain_reduction_db % TRF7970A_RX_GAIN_REDUCTION_DB_PER_LSB)) {
+ dev_warn(trf->dev, "RX Gain must be set in 5 dB increments. Ignored\n");
+ } else {
+ dev_dbg(trf->dev, "RX gain set to -%udB\n", rx_gain_reduction_db);
+ trf->rx_gain_reduction = ((rx_gain_reduction_db /
+ TRF7970A_RX_GAIN_REDUCTION_DB_PER_LSB) <<
+ TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT);
+ trf->custom_rx_gain_reduction = true;
+ }
+ }
+
ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
trf7970a_irq,
IRQF_TRIGGER_RISING | IRQF_ONESHOT,
@@ -2068,37 +2135,37 @@ static int trf7970a_probe(struct spi_device *spi)
mutex_init(&trf->lock);
INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
- trf->regulator = devm_regulator_get(&spi->dev, "vin");
- if (IS_ERR(trf->regulator)) {
- ret = PTR_ERR(trf->regulator);
+ trf->vin_regulator = devm_regulator_get(&spi->dev, "vin");
+ if (IS_ERR(trf->vin_regulator)) {
+ ret = PTR_ERR(trf->vin_regulator);
dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
goto err_destroy_lock;
}
- ret = regulator_enable(trf->regulator);
+ ret = regulator_enable(trf->vin_regulator);
if (ret) {
dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
goto err_destroy_lock;
}
- uvolts = regulator_get_voltage(trf->regulator);
+ uvolts = regulator_get_voltage(trf->vin_regulator);
if (uvolts > 4000000)
trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
- trf->regulator = devm_regulator_get(&spi->dev, "vdd-io");
- if (IS_ERR(trf->regulator)) {
- ret = PTR_ERR(trf->regulator);
+ trf->vddio_regulator = devm_regulator_get(&spi->dev, "vdd-io");
+ if (IS_ERR(trf->vddio_regulator)) {
+ ret = PTR_ERR(trf->vddio_regulator);
dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret);
- goto err_destroy_lock;
+ goto err_disable_vin_regulator;
}
- ret = regulator_enable(trf->regulator);
+ ret = regulator_enable(trf->vddio_regulator);
if (ret) {
dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret);
- goto err_destroy_lock;
+ goto err_disable_vin_regulator;
}
- if (regulator_get_voltage(trf->regulator) == 1800000) {
+ if (regulator_get_voltage(trf->vddio_regulator) == 1800000) {
trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW;
dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n");
}
@@ -2111,7 +2178,7 @@ static int trf7970a_probe(struct spi_device *spi)
if (!trf->ddev) {
dev_err(trf->dev, "Can't allocate NFC digital device\n");
ret = -ENOMEM;
- goto err_disable_regulator;
+ goto err_disable_vddio_regulator;
}
nfc_digital_set_parent_dev(trf->ddev, trf->dev);
@@ -2140,14 +2207,16 @@ err_shutdown:
trf7970a_shutdown(trf);
err_free_ddev:
nfc_digital_free_device(trf->ddev);
-err_disable_regulator:
- regulator_disable(trf->regulator);
+err_disable_vddio_regulator:
+ regulator_disable(trf->vddio_regulator);
+err_disable_vin_regulator:
+ regulator_disable(trf->vin_regulator);
err_destroy_lock:
mutex_destroy(&trf->lock);
return ret;
}
-static int trf7970a_remove(struct spi_device *spi)
+static void trf7970a_remove(struct spi_device *spi)
{
struct trf7970a *trf = spi_get_drvdata(spi);
@@ -2160,11 +2229,10 @@ static int trf7970a_remove(struct spi_device *spi)
nfc_digital_unregister_device(trf->ddev);
nfc_digital_free_device(trf->ddev);
- regulator_disable(trf->regulator);
+ regulator_disable(trf->vddio_regulator);
+ regulator_disable(trf->vin_regulator);
mutex_destroy(&trf->lock);
-
- return 0;
}
#ifdef CONFIG_PM_SLEEP
@@ -2173,8 +2241,6 @@ static int trf7970a_suspend(struct device *dev)
struct spi_device *spi = to_spi_device(dev);
struct trf7970a *trf = spi_get_drvdata(spi);
- dev_dbg(dev, "Suspend\n");
-
mutex_lock(&trf->lock);
trf7970a_shutdown(trf);
@@ -2190,8 +2256,6 @@ static int trf7970a_resume(struct device *dev)
struct trf7970a *trf = spi_get_drvdata(spi);
int ret;
- dev_dbg(dev, "Resume\n");
-
mutex_lock(&trf->lock);
ret = trf7970a_startup(trf);
@@ -2209,8 +2273,6 @@ static int trf7970a_pm_runtime_suspend(struct device *dev)
struct trf7970a *trf = spi_get_drvdata(spi);
int ret;
- dev_dbg(dev, "Runtime suspend\n");
-
mutex_lock(&trf->lock);
ret = trf7970a_power_down(trf);
@@ -2226,8 +2288,6 @@ static int trf7970a_pm_runtime_resume(struct device *dev)
struct trf7970a *trf = spi_get_drvdata(spi);
int ret;
- dev_dbg(dev, "Runtime resume\n");
-
ret = trf7970a_power_up(trf);
if (!ret)
pm_runtime_mark_last_busy(dev);
@@ -2242,7 +2302,7 @@ static const struct dev_pm_ops trf7970a_pm_ops = {
trf7970a_pm_runtime_resume, NULL)
};
-static const struct of_device_id trf7970a_of_match[] = {
+static const struct of_device_id trf7970a_of_match[] __maybe_unused = {
{.compatible = "ti,trf7970a",},
{},
};
generated by cgit (git 2.34.1) at 2025-12-25 01:33:59 +0000