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![William Breathitt Gray](/assets/img/avatar_default.png)
Counter subsystem symbols are only relevant to counter drivers. A COUNTER namespace is created to control the availability of these symbols to modules that import this namespace explicitly. Cc: Patrick Havelange <patrick.havelange@essensium.com> Cc: Jarkko Nikula <jarkko.nikula@linux.intel.com> Cc: Oleksij Rempel <linux@rempel-privat.de> Cc: Pengutronix Kernel Team <kernel@pengutronix.de> Cc: Kamel Bouhara <kamel.bouhara@bootlin.com> Cc: Fabrice Gasnier <fabrice.gasnier@foss.st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Acked-by: David Lechner <david@lechnology.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20220815220321.74161-1-william.gray@linaro.org/ Signed-off-by: William Breathitt Gray <william.gray@linaro.org> Link: https://lore.kernel.org/r/8a756df96c24946547a7ece5caa5f654809c5e7f.1664318353.git.william.gray@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
459 lines
11 KiB
C
459 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2019 David Lechner <david@lechnology.com>
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*
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* Counter driver for Texas Instruments Enhanced Quadrature Encoder Pulse (eQEP)
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*/
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#include <linux/bitops.h>
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#include <linux/counter.h>
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#include <linux/kernel.h>
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#include <linux/mod_devicetable.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/pm_runtime.h>
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#include <linux/regmap.h>
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#include <linux/types.h>
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/* 32-bit registers */
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#define QPOSCNT 0x0
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#define QPOSINIT 0x4
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#define QPOSMAX 0x8
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#define QPOSCMP 0xc
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#define QPOSILAT 0x10
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#define QPOSSLAT 0x14
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#define QPOSLAT 0x18
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#define QUTMR 0x1c
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#define QUPRD 0x20
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/* 16-bit registers */
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#define QWDTMR 0x0 /* 0x24 */
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#define QWDPRD 0x2 /* 0x26 */
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#define QDECCTL 0x4 /* 0x28 */
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#define QEPCTL 0x6 /* 0x2a */
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#define QCAPCTL 0x8 /* 0x2c */
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#define QPOSCTL 0xa /* 0x2e */
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#define QEINT 0xc /* 0x30 */
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#define QFLG 0xe /* 0x32 */
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#define QCLR 0x10 /* 0x34 */
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#define QFRC 0x12 /* 0x36 */
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#define QEPSTS 0x14 /* 0x38 */
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#define QCTMR 0x16 /* 0x3a */
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#define QCPRD 0x18 /* 0x3c */
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#define QCTMRLAT 0x1a /* 0x3e */
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#define QCPRDLAT 0x1c /* 0x40 */
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#define QDECCTL_QSRC_SHIFT 14
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#define QDECCTL_QSRC GENMASK(15, 14)
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#define QDECCTL_SOEN BIT(13)
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#define QDECCTL_SPSEL BIT(12)
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#define QDECCTL_XCR BIT(11)
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#define QDECCTL_SWAP BIT(10)
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#define QDECCTL_IGATE BIT(9)
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#define QDECCTL_QAP BIT(8)
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#define QDECCTL_QBP BIT(7)
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#define QDECCTL_QIP BIT(6)
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#define QDECCTL_QSP BIT(5)
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#define QEPCTL_FREE_SOFT GENMASK(15, 14)
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#define QEPCTL_PCRM GENMASK(13, 12)
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#define QEPCTL_SEI GENMASK(11, 10)
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#define QEPCTL_IEI GENMASK(9, 8)
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#define QEPCTL_SWI BIT(7)
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#define QEPCTL_SEL BIT(6)
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#define QEPCTL_IEL GENMASK(5, 4)
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#define QEPCTL_PHEN BIT(3)
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#define QEPCTL_QCLM BIT(2)
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#define QEPCTL_UTE BIT(1)
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#define QEPCTL_WDE BIT(0)
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/* EQEP Inputs */
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enum {
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TI_EQEP_SIGNAL_QEPA, /* QEPA/XCLK */
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TI_EQEP_SIGNAL_QEPB, /* QEPB/XDIR */
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};
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/* Position Counter Input Modes */
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enum ti_eqep_count_func {
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TI_EQEP_COUNT_FUNC_QUAD_COUNT,
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TI_EQEP_COUNT_FUNC_DIR_COUNT,
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TI_EQEP_COUNT_FUNC_UP_COUNT,
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TI_EQEP_COUNT_FUNC_DOWN_COUNT,
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};
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struct ti_eqep_cnt {
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struct counter_device counter;
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struct regmap *regmap32;
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struct regmap *regmap16;
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};
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static struct ti_eqep_cnt *ti_eqep_count_from_counter(struct counter_device *counter)
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{
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return counter_priv(counter);
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}
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static int ti_eqep_count_read(struct counter_device *counter,
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struct counter_count *count, u64 *val)
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{
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struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);
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u32 cnt;
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regmap_read(priv->regmap32, QPOSCNT, &cnt);
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*val = cnt;
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return 0;
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}
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static int ti_eqep_count_write(struct counter_device *counter,
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struct counter_count *count, u64 val)
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{
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struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);
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u32 max;
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regmap_read(priv->regmap32, QPOSMAX, &max);
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if (val > max)
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return -EINVAL;
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return regmap_write(priv->regmap32, QPOSCNT, val);
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}
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static int ti_eqep_function_read(struct counter_device *counter,
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struct counter_count *count,
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enum counter_function *function)
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{
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struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);
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u32 qdecctl;
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regmap_read(priv->regmap16, QDECCTL, &qdecctl);
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switch ((qdecctl & QDECCTL_QSRC) >> QDECCTL_QSRC_SHIFT) {
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case TI_EQEP_COUNT_FUNC_QUAD_COUNT:
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*function = COUNTER_FUNCTION_QUADRATURE_X4;
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break;
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case TI_EQEP_COUNT_FUNC_DIR_COUNT:
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*function = COUNTER_FUNCTION_PULSE_DIRECTION;
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break;
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case TI_EQEP_COUNT_FUNC_UP_COUNT:
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*function = COUNTER_FUNCTION_INCREASE;
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break;
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case TI_EQEP_COUNT_FUNC_DOWN_COUNT:
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*function = COUNTER_FUNCTION_DECREASE;
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break;
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}
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return 0;
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}
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static int ti_eqep_function_write(struct counter_device *counter,
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struct counter_count *count,
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enum counter_function function)
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{
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struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);
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enum ti_eqep_count_func qsrc;
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switch (function) {
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case COUNTER_FUNCTION_QUADRATURE_X4:
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qsrc = TI_EQEP_COUNT_FUNC_QUAD_COUNT;
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break;
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case COUNTER_FUNCTION_PULSE_DIRECTION:
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qsrc = TI_EQEP_COUNT_FUNC_DIR_COUNT;
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break;
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case COUNTER_FUNCTION_INCREASE:
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qsrc = TI_EQEP_COUNT_FUNC_UP_COUNT;
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break;
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case COUNTER_FUNCTION_DECREASE:
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qsrc = TI_EQEP_COUNT_FUNC_DOWN_COUNT;
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break;
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default:
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/* should never reach this path */
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return -EINVAL;
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}
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return regmap_write_bits(priv->regmap16, QDECCTL, QDECCTL_QSRC,
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qsrc << QDECCTL_QSRC_SHIFT);
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}
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static int ti_eqep_action_read(struct counter_device *counter,
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struct counter_count *count,
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struct counter_synapse *synapse,
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enum counter_synapse_action *action)
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{
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struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);
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enum counter_function function;
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u32 qdecctl;
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int err;
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err = ti_eqep_function_read(counter, count, &function);
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if (err)
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return err;
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switch (function) {
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case COUNTER_FUNCTION_QUADRATURE_X4:
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/* In quadrature mode, the rising and falling edge of both
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* QEPA and QEPB trigger QCLK.
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*/
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*action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
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return 0;
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case COUNTER_FUNCTION_PULSE_DIRECTION:
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/* In direction-count mode only rising edge of QEPA is counted
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* and QEPB gives direction.
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*/
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switch (synapse->signal->id) {
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case TI_EQEP_SIGNAL_QEPA:
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*action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
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return 0;
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case TI_EQEP_SIGNAL_QEPB:
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*action = COUNTER_SYNAPSE_ACTION_NONE;
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return 0;
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default:
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/* should never reach this path */
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return -EINVAL;
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}
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case COUNTER_FUNCTION_INCREASE:
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case COUNTER_FUNCTION_DECREASE:
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/* In up/down-count modes only QEPA is counted and QEPB is not
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* used.
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*/
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switch (synapse->signal->id) {
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case TI_EQEP_SIGNAL_QEPA:
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err = regmap_read(priv->regmap16, QDECCTL, &qdecctl);
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if (err)
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return err;
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if (qdecctl & QDECCTL_XCR)
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*action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
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else
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*action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
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return 0;
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case TI_EQEP_SIGNAL_QEPB:
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*action = COUNTER_SYNAPSE_ACTION_NONE;
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return 0;
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default:
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/* should never reach this path */
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return -EINVAL;
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}
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default:
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/* should never reach this path */
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return -EINVAL;
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}
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}
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static const struct counter_ops ti_eqep_counter_ops = {
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.count_read = ti_eqep_count_read,
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.count_write = ti_eqep_count_write,
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.function_read = ti_eqep_function_read,
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.function_write = ti_eqep_function_write,
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.action_read = ti_eqep_action_read,
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};
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static int ti_eqep_position_ceiling_read(struct counter_device *counter,
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struct counter_count *count,
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u64 *ceiling)
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{
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struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);
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u32 qposmax;
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regmap_read(priv->regmap32, QPOSMAX, &qposmax);
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*ceiling = qposmax;
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return 0;
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}
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static int ti_eqep_position_ceiling_write(struct counter_device *counter,
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struct counter_count *count,
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u64 ceiling)
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{
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struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);
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if (ceiling != (u32)ceiling)
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return -ERANGE;
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regmap_write(priv->regmap32, QPOSMAX, ceiling);
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return 0;
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}
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static int ti_eqep_position_enable_read(struct counter_device *counter,
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struct counter_count *count, u8 *enable)
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{
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struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);
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u32 qepctl;
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regmap_read(priv->regmap16, QEPCTL, &qepctl);
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*enable = !!(qepctl & QEPCTL_PHEN);
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return 0;
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}
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static int ti_eqep_position_enable_write(struct counter_device *counter,
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struct counter_count *count, u8 enable)
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{
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struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter);
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regmap_write_bits(priv->regmap16, QEPCTL, QEPCTL_PHEN, enable ? -1 : 0);
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return 0;
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}
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static struct counter_comp ti_eqep_position_ext[] = {
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COUNTER_COMP_CEILING(ti_eqep_position_ceiling_read,
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ti_eqep_position_ceiling_write),
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COUNTER_COMP_ENABLE(ti_eqep_position_enable_read,
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ti_eqep_position_enable_write),
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};
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static struct counter_signal ti_eqep_signals[] = {
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[TI_EQEP_SIGNAL_QEPA] = {
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.id = TI_EQEP_SIGNAL_QEPA,
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.name = "QEPA"
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},
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[TI_EQEP_SIGNAL_QEPB] = {
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.id = TI_EQEP_SIGNAL_QEPB,
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.name = "QEPB"
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},
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};
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static const enum counter_function ti_eqep_position_functions[] = {
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COUNTER_FUNCTION_QUADRATURE_X4,
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COUNTER_FUNCTION_PULSE_DIRECTION,
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COUNTER_FUNCTION_INCREASE,
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COUNTER_FUNCTION_DECREASE,
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};
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static const enum counter_synapse_action ti_eqep_position_synapse_actions[] = {
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COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
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COUNTER_SYNAPSE_ACTION_RISING_EDGE,
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COUNTER_SYNAPSE_ACTION_NONE,
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};
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static struct counter_synapse ti_eqep_position_synapses[] = {
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{
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.actions_list = ti_eqep_position_synapse_actions,
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.num_actions = ARRAY_SIZE(ti_eqep_position_synapse_actions),
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.signal = &ti_eqep_signals[TI_EQEP_SIGNAL_QEPA],
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},
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{
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.actions_list = ti_eqep_position_synapse_actions,
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.num_actions = ARRAY_SIZE(ti_eqep_position_synapse_actions),
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.signal = &ti_eqep_signals[TI_EQEP_SIGNAL_QEPB],
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},
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};
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static struct counter_count ti_eqep_counts[] = {
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{
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.id = 0,
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.name = "QPOSCNT",
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.functions_list = ti_eqep_position_functions,
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.num_functions = ARRAY_SIZE(ti_eqep_position_functions),
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.synapses = ti_eqep_position_synapses,
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.num_synapses = ARRAY_SIZE(ti_eqep_position_synapses),
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.ext = ti_eqep_position_ext,
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.num_ext = ARRAY_SIZE(ti_eqep_position_ext),
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},
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};
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static const struct regmap_config ti_eqep_regmap32_config = {
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.name = "32-bit",
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.reg_bits = 32,
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.val_bits = 32,
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.reg_stride = 4,
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.max_register = QUPRD,
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};
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static const struct regmap_config ti_eqep_regmap16_config = {
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.name = "16-bit",
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.reg_bits = 16,
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.val_bits = 16,
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.reg_stride = 2,
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.max_register = QCPRDLAT,
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};
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static int ti_eqep_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct counter_device *counter;
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struct ti_eqep_cnt *priv;
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void __iomem *base;
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int err;
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counter = devm_counter_alloc(dev, sizeof(*priv));
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if (!counter)
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return -ENOMEM;
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priv = counter_priv(counter);
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base = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(base))
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return PTR_ERR(base);
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priv->regmap32 = devm_regmap_init_mmio(dev, base,
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&ti_eqep_regmap32_config);
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if (IS_ERR(priv->regmap32))
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return PTR_ERR(priv->regmap32);
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priv->regmap16 = devm_regmap_init_mmio(dev, base + 0x24,
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&ti_eqep_regmap16_config);
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if (IS_ERR(priv->regmap16))
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return PTR_ERR(priv->regmap16);
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counter->name = dev_name(dev);
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counter->parent = dev;
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counter->ops = &ti_eqep_counter_ops;
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counter->counts = ti_eqep_counts;
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counter->num_counts = ARRAY_SIZE(ti_eqep_counts);
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counter->signals = ti_eqep_signals;
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counter->num_signals = ARRAY_SIZE(ti_eqep_signals);
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platform_set_drvdata(pdev, counter);
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/*
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* Need to make sure power is turned on. On AM33xx, this comes from the
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* parent PWMSS bus driver. On AM17xx, this comes from the PSC power
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* domain.
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*/
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pm_runtime_enable(dev);
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pm_runtime_get_sync(dev);
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err = counter_add(counter);
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if (err < 0) {
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pm_runtime_put_sync(dev);
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pm_runtime_disable(dev);
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return err;
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}
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return 0;
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}
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static int ti_eqep_remove(struct platform_device *pdev)
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{
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struct counter_device *counter = platform_get_drvdata(pdev);
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struct device *dev = &pdev->dev;
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counter_unregister(counter);
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pm_runtime_put_sync(dev);
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pm_runtime_disable(dev);
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return 0;
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}
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static const struct of_device_id ti_eqep_of_match[] = {
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{ .compatible = "ti,am3352-eqep", },
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{ },
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};
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MODULE_DEVICE_TABLE(of, ti_eqep_of_match);
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static struct platform_driver ti_eqep_driver = {
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.probe = ti_eqep_probe,
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.remove = ti_eqep_remove,
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.driver = {
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.name = "ti-eqep-cnt",
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.of_match_table = ti_eqep_of_match,
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},
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};
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module_platform_driver(ti_eqep_driver);
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MODULE_AUTHOR("David Lechner <david@lechnology.com>");
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MODULE_DESCRIPTION("TI eQEP counter driver");
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MODULE_LICENSE("GPL v2");
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MODULE_IMPORT_NS(COUNTER);
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