// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2019 David Lechner * * Counter driver for Texas Instruments Enhanced Quadrature Encoder Pulse (eQEP) */ #include #include #include #include #include #include #include #include #include /* 32-bit registers */ #define QPOSCNT 0x0 #define QPOSINIT 0x4 #define QPOSMAX 0x8 #define QPOSCMP 0xc #define QPOSILAT 0x10 #define QPOSSLAT 0x14 #define QPOSLAT 0x18 #define QUTMR 0x1c #define QUPRD 0x20 /* 16-bit registers */ #define QWDTMR 0x0 /* 0x24 */ #define QWDPRD 0x2 /* 0x26 */ #define QDECCTL 0x4 /* 0x28 */ #define QEPCTL 0x6 /* 0x2a */ #define QCAPCTL 0x8 /* 0x2c */ #define QPOSCTL 0xa /* 0x2e */ #define QEINT 0xc /* 0x30 */ #define QFLG 0xe /* 0x32 */ #define QCLR 0x10 /* 0x34 */ #define QFRC 0x12 /* 0x36 */ #define QEPSTS 0x14 /* 0x38 */ #define QCTMR 0x16 /* 0x3a */ #define QCPRD 0x18 /* 0x3c */ #define QCTMRLAT 0x1a /* 0x3e */ #define QCPRDLAT 0x1c /* 0x40 */ #define QDECCTL_QSRC_SHIFT 14 #define QDECCTL_QSRC GENMASK(15, 14) #define QDECCTL_SOEN BIT(13) #define QDECCTL_SPSEL BIT(12) #define QDECCTL_XCR BIT(11) #define QDECCTL_SWAP BIT(10) #define QDECCTL_IGATE BIT(9) #define QDECCTL_QAP BIT(8) #define QDECCTL_QBP BIT(7) #define QDECCTL_QIP BIT(6) #define QDECCTL_QSP BIT(5) #define QEPCTL_FREE_SOFT GENMASK(15, 14) #define QEPCTL_PCRM GENMASK(13, 12) #define QEPCTL_SEI GENMASK(11, 10) #define QEPCTL_IEI GENMASK(9, 8) #define QEPCTL_SWI BIT(7) #define QEPCTL_SEL BIT(6) #define QEPCTL_IEL GENMASK(5, 4) #define QEPCTL_PHEN BIT(3) #define QEPCTL_QCLM BIT(2) #define QEPCTL_UTE BIT(1) #define QEPCTL_WDE BIT(0) /* EQEP Inputs */ enum { TI_EQEP_SIGNAL_QEPA, /* QEPA/XCLK */ TI_EQEP_SIGNAL_QEPB, /* QEPB/XDIR */ }; /* Position Counter Input Modes */ enum ti_eqep_count_func { TI_EQEP_COUNT_FUNC_QUAD_COUNT, TI_EQEP_COUNT_FUNC_DIR_COUNT, TI_EQEP_COUNT_FUNC_UP_COUNT, TI_EQEP_COUNT_FUNC_DOWN_COUNT, }; struct ti_eqep_cnt { struct counter_device counter; struct regmap *regmap32; struct regmap *regmap16; }; static struct ti_eqep_cnt *ti_eqep_count_from_counter(struct counter_device *counter) { return counter_priv(counter); } static int ti_eqep_count_read(struct counter_device *counter, struct counter_count *count, u64 *val) { struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter); u32 cnt; regmap_read(priv->regmap32, QPOSCNT, &cnt); *val = cnt; return 0; } static int ti_eqep_count_write(struct counter_device *counter, struct counter_count *count, u64 val) { struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter); u32 max; regmap_read(priv->regmap32, QPOSMAX, &max); if (val > max) return -EINVAL; return regmap_write(priv->regmap32, QPOSCNT, val); } static int ti_eqep_function_read(struct counter_device *counter, struct counter_count *count, enum counter_function *function) { struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter); u32 qdecctl; regmap_read(priv->regmap16, QDECCTL, &qdecctl); switch ((qdecctl & QDECCTL_QSRC) >> QDECCTL_QSRC_SHIFT) { case TI_EQEP_COUNT_FUNC_QUAD_COUNT: *function = COUNTER_FUNCTION_QUADRATURE_X4; break; case TI_EQEP_COUNT_FUNC_DIR_COUNT: *function = COUNTER_FUNCTION_PULSE_DIRECTION; break; case TI_EQEP_COUNT_FUNC_UP_COUNT: *function = COUNTER_FUNCTION_INCREASE; break; case TI_EQEP_COUNT_FUNC_DOWN_COUNT: *function = COUNTER_FUNCTION_DECREASE; break; } return 0; } static int ti_eqep_function_write(struct counter_device *counter, struct counter_count *count, enum counter_function function) { struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter); enum ti_eqep_count_func qsrc; switch (function) { case COUNTER_FUNCTION_QUADRATURE_X4: qsrc = TI_EQEP_COUNT_FUNC_QUAD_COUNT; break; case COUNTER_FUNCTION_PULSE_DIRECTION: qsrc = TI_EQEP_COUNT_FUNC_DIR_COUNT; break; case COUNTER_FUNCTION_INCREASE: qsrc = TI_EQEP_COUNT_FUNC_UP_COUNT; break; case COUNTER_FUNCTION_DECREASE: qsrc = TI_EQEP_COUNT_FUNC_DOWN_COUNT; break; default: /* should never reach this path */ return -EINVAL; } return regmap_write_bits(priv->regmap16, QDECCTL, QDECCTL_QSRC, qsrc << QDECCTL_QSRC_SHIFT); } static int ti_eqep_action_read(struct counter_device *counter, struct counter_count *count, struct counter_synapse *synapse, enum counter_synapse_action *action) { struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter); enum counter_function function; u32 qdecctl; int err; err = ti_eqep_function_read(counter, count, &function); if (err) return err; switch (function) { case COUNTER_FUNCTION_QUADRATURE_X4: /* In quadrature mode, the rising and falling edge of both * QEPA and QEPB trigger QCLK. */ *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES; return 0; case COUNTER_FUNCTION_PULSE_DIRECTION: /* In direction-count mode only rising edge of QEPA is counted * and QEPB gives direction. */ switch (synapse->signal->id) { case TI_EQEP_SIGNAL_QEPA: *action = COUNTER_SYNAPSE_ACTION_RISING_EDGE; return 0; case TI_EQEP_SIGNAL_QEPB: *action = COUNTER_SYNAPSE_ACTION_NONE; return 0; default: /* should never reach this path */ return -EINVAL; } case COUNTER_FUNCTION_INCREASE: case COUNTER_FUNCTION_DECREASE: /* In up/down-count modes only QEPA is counted and QEPB is not * used. */ switch (synapse->signal->id) { case TI_EQEP_SIGNAL_QEPA: err = regmap_read(priv->regmap16, QDECCTL, &qdecctl); if (err) return err; if (qdecctl & QDECCTL_XCR) *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES; else *action = COUNTER_SYNAPSE_ACTION_RISING_EDGE; return 0; case TI_EQEP_SIGNAL_QEPB: *action = COUNTER_SYNAPSE_ACTION_NONE; return 0; default: /* should never reach this path */ return -EINVAL; } default: /* should never reach this path */ return -EINVAL; } } static const struct counter_ops ti_eqep_counter_ops = { .count_read = ti_eqep_count_read, .count_write = ti_eqep_count_write, .function_read = ti_eqep_function_read, .function_write = ti_eqep_function_write, .action_read = ti_eqep_action_read, }; static int ti_eqep_position_ceiling_read(struct counter_device *counter, struct counter_count *count, u64 *ceiling) { struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter); u32 qposmax; regmap_read(priv->regmap32, QPOSMAX, &qposmax); *ceiling = qposmax; return 0; } static int ti_eqep_position_ceiling_write(struct counter_device *counter, struct counter_count *count, u64 ceiling) { struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter); if (ceiling != (u32)ceiling) return -ERANGE; regmap_write(priv->regmap32, QPOSMAX, ceiling); return 0; } static int ti_eqep_position_enable_read(struct counter_device *counter, struct counter_count *count, u8 *enable) { struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter); u32 qepctl; regmap_read(priv->regmap16, QEPCTL, &qepctl); *enable = !!(qepctl & QEPCTL_PHEN); return 0; } static int ti_eqep_position_enable_write(struct counter_device *counter, struct counter_count *count, u8 enable) { struct ti_eqep_cnt *priv = ti_eqep_count_from_counter(counter); regmap_write_bits(priv->regmap16, QEPCTL, QEPCTL_PHEN, enable ? -1 : 0); return 0; } static struct counter_comp ti_eqep_position_ext[] = { COUNTER_COMP_CEILING(ti_eqep_position_ceiling_read, ti_eqep_position_ceiling_write), COUNTER_COMP_ENABLE(ti_eqep_position_enable_read, ti_eqep_position_enable_write), }; static struct counter_signal ti_eqep_signals[] = { [TI_EQEP_SIGNAL_QEPA] = { .id = TI_EQEP_SIGNAL_QEPA, .name = "QEPA" }, [TI_EQEP_SIGNAL_QEPB] = { .id = TI_EQEP_SIGNAL_QEPB, .name = "QEPB" }, }; static const enum counter_function ti_eqep_position_functions[] = { COUNTER_FUNCTION_QUADRATURE_X4, COUNTER_FUNCTION_PULSE_DIRECTION, COUNTER_FUNCTION_INCREASE, COUNTER_FUNCTION_DECREASE, }; static const enum counter_synapse_action ti_eqep_position_synapse_actions[] = { COUNTER_SYNAPSE_ACTION_BOTH_EDGES, COUNTER_SYNAPSE_ACTION_RISING_EDGE, COUNTER_SYNAPSE_ACTION_NONE, }; static struct counter_synapse ti_eqep_position_synapses[] = { { .actions_list = ti_eqep_position_synapse_actions, .num_actions = ARRAY_SIZE(ti_eqep_position_synapse_actions), .signal = &ti_eqep_signals[TI_EQEP_SIGNAL_QEPA], }, { .actions_list = ti_eqep_position_synapse_actions, .num_actions = ARRAY_SIZE(ti_eqep_position_synapse_actions), .signal = &ti_eqep_signals[TI_EQEP_SIGNAL_QEPB], }, }; static struct counter_count ti_eqep_counts[] = { { .id = 0, .name = "QPOSCNT", .functions_list = ti_eqep_position_functions, .num_functions = ARRAY_SIZE(ti_eqep_position_functions), .synapses = ti_eqep_position_synapses, .num_synapses = ARRAY_SIZE(ti_eqep_position_synapses), .ext = ti_eqep_position_ext, .num_ext = ARRAY_SIZE(ti_eqep_position_ext), }, }; static const struct regmap_config ti_eqep_regmap32_config = { .name = "32-bit", .reg_bits = 32, .val_bits = 32, .reg_stride = 4, .max_register = QUPRD, }; static const struct regmap_config ti_eqep_regmap16_config = { .name = "16-bit", .reg_bits = 16, .val_bits = 16, .reg_stride = 2, .max_register = QCPRDLAT, }; static int ti_eqep_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct ti_eqep_cnt *priv; void __iomem *base; int err; priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(base)) return PTR_ERR(base); priv->regmap32 = devm_regmap_init_mmio(dev, base, &ti_eqep_regmap32_config); if (IS_ERR(priv->regmap32)) return PTR_ERR(priv->regmap32); priv->regmap16 = devm_regmap_init_mmio(dev, base + 0x24, &ti_eqep_regmap16_config); if (IS_ERR(priv->regmap16)) return PTR_ERR(priv->regmap16); priv->counter.name = dev_name(dev); priv->counter.parent = dev; priv->counter.ops = &ti_eqep_counter_ops; priv->counter.counts = ti_eqep_counts; priv->counter.num_counts = ARRAY_SIZE(ti_eqep_counts); priv->counter.signals = ti_eqep_signals; priv->counter.num_signals = ARRAY_SIZE(ti_eqep_signals); priv->counter.priv = priv; platform_set_drvdata(pdev, priv); /* * Need to make sure power is turned on. On AM33xx, this comes from the * parent PWMSS bus driver. On AM17xx, this comes from the PSC power * domain. */ pm_runtime_enable(dev); pm_runtime_get_sync(dev); err = counter_register(&priv->counter); if (err < 0) { pm_runtime_put_sync(dev); pm_runtime_disable(dev); return err; } return 0; } static int ti_eqep_remove(struct platform_device *pdev) { struct ti_eqep_cnt *priv = platform_get_drvdata(pdev); struct device *dev = &pdev->dev; counter_unregister(&priv->counter); pm_runtime_put_sync(dev); pm_runtime_disable(dev); return 0; } static const struct of_device_id ti_eqep_of_match[] = { { .compatible = "ti,am3352-eqep", }, { }, }; MODULE_DEVICE_TABLE(of, ti_eqep_of_match); static struct platform_driver ti_eqep_driver = { .probe = ti_eqep_probe, .remove = ti_eqep_remove, .driver = { .name = "ti-eqep-cnt", .of_match_table = ti_eqep_of_match, }, }; module_platform_driver(ti_eqep_driver); MODULE_AUTHOR("David Lechner "); MODULE_DESCRIPTION("TI eQEP counter driver"); MODULE_LICENSE("GPL v2");