527 lines
13 KiB
C
527 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Intel Quadrature Encoder Peripheral driver
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*
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* Copyright (C) 2019-2021 Intel Corporation
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*
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* Author: Felipe Balbi (Intel)
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* Author: Jarkko Nikula <jarkko.nikula@linux.intel.com>
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* Author: Raymond Tan <raymond.tan@intel.com>
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*/
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#include <linux/counter.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/pci.h>
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#include <linux/pm_runtime.h>
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#define INTEL_QEPCON 0x00
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#define INTEL_QEPFLT 0x04
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#define INTEL_QEPCOUNT 0x08
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#define INTEL_QEPMAX 0x0c
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#define INTEL_QEPWDT 0x10
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#define INTEL_QEPCAPDIV 0x14
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#define INTEL_QEPCNTR 0x18
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#define INTEL_QEPCAPBUF 0x1c
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#define INTEL_QEPINT_STAT 0x20
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#define INTEL_QEPINT_MASK 0x24
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/* QEPCON */
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#define INTEL_QEPCON_EN BIT(0)
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#define INTEL_QEPCON_FLT_EN BIT(1)
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#define INTEL_QEPCON_EDGE_A BIT(2)
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#define INTEL_QEPCON_EDGE_B BIT(3)
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#define INTEL_QEPCON_EDGE_INDX BIT(4)
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#define INTEL_QEPCON_SWPAB BIT(5)
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#define INTEL_QEPCON_OP_MODE BIT(6)
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#define INTEL_QEPCON_PH_ERR BIT(7)
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#define INTEL_QEPCON_COUNT_RST_MODE BIT(8)
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#define INTEL_QEPCON_INDX_GATING_MASK GENMASK(10, 9)
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#define INTEL_QEPCON_INDX_GATING(n) (((n) & 3) << 9)
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#define INTEL_QEPCON_INDX_PAL_PBL INTEL_QEPCON_INDX_GATING(0)
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#define INTEL_QEPCON_INDX_PAL_PBH INTEL_QEPCON_INDX_GATING(1)
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#define INTEL_QEPCON_INDX_PAH_PBL INTEL_QEPCON_INDX_GATING(2)
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#define INTEL_QEPCON_INDX_PAH_PBH INTEL_QEPCON_INDX_GATING(3)
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#define INTEL_QEPCON_CAP_MODE BIT(11)
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#define INTEL_QEPCON_FIFO_THRE_MASK GENMASK(14, 12)
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#define INTEL_QEPCON_FIFO_THRE(n) ((((n) - 1) & 7) << 12)
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#define INTEL_QEPCON_FIFO_EMPTY BIT(15)
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/* QEPFLT */
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#define INTEL_QEPFLT_MAX_COUNT(n) ((n) & 0x1fffff)
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/* QEPINT */
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#define INTEL_QEPINT_FIFOCRIT BIT(5)
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#define INTEL_QEPINT_FIFOENTRY BIT(4)
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#define INTEL_QEPINT_QEPDIR BIT(3)
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#define INTEL_QEPINT_QEPRST_UP BIT(2)
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#define INTEL_QEPINT_QEPRST_DOWN BIT(1)
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#define INTEL_QEPINT_WDT BIT(0)
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#define INTEL_QEPINT_MASK_ALL GENMASK(5, 0)
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#define INTEL_QEP_CLK_PERIOD_NS 10
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struct intel_qep {
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struct mutex lock;
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struct device *dev;
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void __iomem *regs;
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bool enabled;
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/* Context save registers */
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u32 qepcon;
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u32 qepflt;
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u32 qepmax;
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};
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static inline u32 intel_qep_readl(struct intel_qep *qep, u32 offset)
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{
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return readl(qep->regs + offset);
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}
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static inline void intel_qep_writel(struct intel_qep *qep,
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u32 offset, u32 value)
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{
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writel(value, qep->regs + offset);
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}
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static void intel_qep_init(struct intel_qep *qep)
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{
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u32 reg;
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reg = intel_qep_readl(qep, INTEL_QEPCON);
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reg &= ~INTEL_QEPCON_EN;
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intel_qep_writel(qep, INTEL_QEPCON, reg);
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qep->enabled = false;
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/*
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* Make sure peripheral is disabled by flushing the write with
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* a dummy read
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*/
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reg = intel_qep_readl(qep, INTEL_QEPCON);
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reg &= ~(INTEL_QEPCON_OP_MODE | INTEL_QEPCON_FLT_EN);
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reg |= INTEL_QEPCON_EDGE_A | INTEL_QEPCON_EDGE_B |
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INTEL_QEPCON_EDGE_INDX | INTEL_QEPCON_COUNT_RST_MODE;
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intel_qep_writel(qep, INTEL_QEPCON, reg);
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intel_qep_writel(qep, INTEL_QEPINT_MASK, INTEL_QEPINT_MASK_ALL);
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}
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static int intel_qep_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 intel_qep *const qep = counter_priv(counter);
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pm_runtime_get_sync(qep->dev);
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*val = intel_qep_readl(qep, INTEL_QEPCOUNT);
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pm_runtime_put(qep->dev);
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return 0;
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}
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static const enum counter_function intel_qep_count_functions[] = {
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COUNTER_FUNCTION_QUADRATURE_X4,
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};
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static int intel_qep_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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*function = COUNTER_FUNCTION_QUADRATURE_X4;
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return 0;
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}
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static const enum counter_synapse_action intel_qep_synapse_actions[] = {
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COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
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};
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static int intel_qep_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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*action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
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return 0;
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}
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static const struct counter_ops intel_qep_counter_ops = {
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.count_read = intel_qep_count_read,
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.function_read = intel_qep_function_read,
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.action_read = intel_qep_action_read,
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};
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#define INTEL_QEP_SIGNAL(_id, _name) { \
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.id = (_id), \
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.name = (_name), \
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}
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static struct counter_signal intel_qep_signals[] = {
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INTEL_QEP_SIGNAL(0, "Phase A"),
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INTEL_QEP_SIGNAL(1, "Phase B"),
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INTEL_QEP_SIGNAL(2, "Index"),
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};
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#define INTEL_QEP_SYNAPSE(_signal_id) { \
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.actions_list = intel_qep_synapse_actions, \
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.num_actions = ARRAY_SIZE(intel_qep_synapse_actions), \
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.signal = &intel_qep_signals[(_signal_id)], \
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}
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static struct counter_synapse intel_qep_count_synapses[] = {
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INTEL_QEP_SYNAPSE(0),
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INTEL_QEP_SYNAPSE(1),
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INTEL_QEP_SYNAPSE(2),
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};
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static int intel_qep_ceiling_read(struct counter_device *counter,
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struct counter_count *count, u64 *ceiling)
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{
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struct intel_qep *qep = counter_priv(counter);
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pm_runtime_get_sync(qep->dev);
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*ceiling = intel_qep_readl(qep, INTEL_QEPMAX);
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pm_runtime_put(qep->dev);
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return 0;
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}
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static int intel_qep_ceiling_write(struct counter_device *counter,
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struct counter_count *count, u64 max)
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{
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struct intel_qep *qep = counter_priv(counter);
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int ret = 0;
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/* Intel QEP ceiling configuration only supports 32-bit values */
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if (max != (u32)max)
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return -ERANGE;
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mutex_lock(&qep->lock);
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if (qep->enabled) {
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ret = -EBUSY;
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goto out;
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}
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pm_runtime_get_sync(qep->dev);
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intel_qep_writel(qep, INTEL_QEPMAX, max);
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pm_runtime_put(qep->dev);
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out:
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mutex_unlock(&qep->lock);
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return ret;
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}
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static int intel_qep_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 intel_qep *qep = counter_priv(counter);
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*enable = qep->enabled;
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return 0;
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}
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static int intel_qep_enable_write(struct counter_device *counter,
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struct counter_count *count, u8 val)
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{
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struct intel_qep *qep = counter_priv(counter);
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u32 reg;
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bool changed;
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mutex_lock(&qep->lock);
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changed = val ^ qep->enabled;
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if (!changed)
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goto out;
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pm_runtime_get_sync(qep->dev);
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reg = intel_qep_readl(qep, INTEL_QEPCON);
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if (val) {
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/* Enable peripheral and keep runtime PM always on */
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reg |= INTEL_QEPCON_EN;
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pm_runtime_get_noresume(qep->dev);
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} else {
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/* Let runtime PM be idle and disable peripheral */
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pm_runtime_put_noidle(qep->dev);
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reg &= ~INTEL_QEPCON_EN;
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}
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intel_qep_writel(qep, INTEL_QEPCON, reg);
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pm_runtime_put(qep->dev);
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qep->enabled = val;
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out:
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mutex_unlock(&qep->lock);
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return 0;
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}
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static int intel_qep_spike_filter_ns_read(struct counter_device *counter,
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struct counter_count *count,
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u64 *length)
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{
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struct intel_qep *qep = counter_priv(counter);
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u32 reg;
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pm_runtime_get_sync(qep->dev);
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reg = intel_qep_readl(qep, INTEL_QEPCON);
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if (!(reg & INTEL_QEPCON_FLT_EN)) {
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pm_runtime_put(qep->dev);
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return 0;
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}
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reg = INTEL_QEPFLT_MAX_COUNT(intel_qep_readl(qep, INTEL_QEPFLT));
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pm_runtime_put(qep->dev);
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*length = (reg + 2) * INTEL_QEP_CLK_PERIOD_NS;
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return 0;
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}
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static int intel_qep_spike_filter_ns_write(struct counter_device *counter,
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struct counter_count *count,
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u64 length)
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{
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struct intel_qep *qep = counter_priv(counter);
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u32 reg;
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bool enable;
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int ret = 0;
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/*
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* Spike filter length is (MAX_COUNT + 2) clock periods.
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* Disable filter when userspace writes 0, enable for valid
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* nanoseconds values and error out otherwise.
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*/
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do_div(length, INTEL_QEP_CLK_PERIOD_NS);
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if (length == 0) {
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enable = false;
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length = 0;
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} else if (length >= 2) {
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enable = true;
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length -= 2;
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} else {
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return -EINVAL;
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}
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if (length > INTEL_QEPFLT_MAX_COUNT(length))
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return -ERANGE;
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mutex_lock(&qep->lock);
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if (qep->enabled) {
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ret = -EBUSY;
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goto out;
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}
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pm_runtime_get_sync(qep->dev);
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reg = intel_qep_readl(qep, INTEL_QEPCON);
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if (enable)
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reg |= INTEL_QEPCON_FLT_EN;
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else
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reg &= ~INTEL_QEPCON_FLT_EN;
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intel_qep_writel(qep, INTEL_QEPFLT, length);
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intel_qep_writel(qep, INTEL_QEPCON, reg);
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pm_runtime_put(qep->dev);
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out:
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mutex_unlock(&qep->lock);
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return ret;
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}
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static int intel_qep_preset_enable_read(struct counter_device *counter,
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struct counter_count *count,
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u8 *preset_enable)
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{
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struct intel_qep *qep = counter_priv(counter);
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u32 reg;
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pm_runtime_get_sync(qep->dev);
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reg = intel_qep_readl(qep, INTEL_QEPCON);
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pm_runtime_put(qep->dev);
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*preset_enable = !(reg & INTEL_QEPCON_COUNT_RST_MODE);
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return 0;
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}
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static int intel_qep_preset_enable_write(struct counter_device *counter,
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struct counter_count *count, u8 val)
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{
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struct intel_qep *qep = counter_priv(counter);
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u32 reg;
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int ret = 0;
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mutex_lock(&qep->lock);
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if (qep->enabled) {
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ret = -EBUSY;
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goto out;
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}
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pm_runtime_get_sync(qep->dev);
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reg = intel_qep_readl(qep, INTEL_QEPCON);
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if (val)
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reg &= ~INTEL_QEPCON_COUNT_RST_MODE;
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else
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reg |= INTEL_QEPCON_COUNT_RST_MODE;
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intel_qep_writel(qep, INTEL_QEPCON, reg);
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pm_runtime_put(qep->dev);
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out:
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mutex_unlock(&qep->lock);
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return ret;
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}
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static struct counter_comp intel_qep_count_ext[] = {
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COUNTER_COMP_ENABLE(intel_qep_enable_read, intel_qep_enable_write),
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COUNTER_COMP_CEILING(intel_qep_ceiling_read, intel_qep_ceiling_write),
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COUNTER_COMP_PRESET_ENABLE(intel_qep_preset_enable_read,
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intel_qep_preset_enable_write),
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COUNTER_COMP_COUNT_U64("spike_filter_ns",
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intel_qep_spike_filter_ns_read,
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intel_qep_spike_filter_ns_write),
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};
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static struct counter_count intel_qep_counter_count[] = {
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{
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.id = 0,
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.name = "Channel 1 Count",
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.functions_list = intel_qep_count_functions,
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.num_functions = ARRAY_SIZE(intel_qep_count_functions),
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.synapses = intel_qep_count_synapses,
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.num_synapses = ARRAY_SIZE(intel_qep_count_synapses),
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.ext = intel_qep_count_ext,
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.num_ext = ARRAY_SIZE(intel_qep_count_ext),
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},
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};
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static int intel_qep_probe(struct pci_dev *pci, const struct pci_device_id *id)
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{
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struct counter_device *counter;
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struct intel_qep *qep;
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struct device *dev = &pci->dev;
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void __iomem *regs;
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int ret;
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counter = devm_counter_alloc(dev, sizeof(*qep));
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if (!counter)
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return -ENOMEM;
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qep = counter_priv(counter);
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ret = pcim_enable_device(pci);
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if (ret)
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return ret;
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pci_set_master(pci);
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ret = pcim_iomap_regions(pci, BIT(0), pci_name(pci));
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if (ret)
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return ret;
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regs = pcim_iomap_table(pci)[0];
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if (!regs)
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return -ENOMEM;
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qep->dev = dev;
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qep->regs = regs;
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mutex_init(&qep->lock);
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intel_qep_init(qep);
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pci_set_drvdata(pci, qep);
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counter->name = pci_name(pci);
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counter->parent = dev;
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counter->ops = &intel_qep_counter_ops;
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counter->counts = intel_qep_counter_count;
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counter->num_counts = ARRAY_SIZE(intel_qep_counter_count);
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counter->signals = intel_qep_signals;
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counter->num_signals = ARRAY_SIZE(intel_qep_signals);
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qep->enabled = false;
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pm_runtime_put(dev);
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pm_runtime_allow(dev);
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ret = devm_counter_add(&pci->dev, counter);
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if (ret < 0)
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return dev_err_probe(&pci->dev, ret, "Failed to add counter\n");
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return 0;
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}
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static void intel_qep_remove(struct pci_dev *pci)
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{
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struct intel_qep *qep = pci_get_drvdata(pci);
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struct device *dev = &pci->dev;
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pm_runtime_forbid(dev);
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if (!qep->enabled)
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pm_runtime_get(dev);
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intel_qep_writel(qep, INTEL_QEPCON, 0);
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}
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static int __maybe_unused intel_qep_suspend(struct device *dev)
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{
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struct pci_dev *pdev = to_pci_dev(dev);
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struct intel_qep *qep = pci_get_drvdata(pdev);
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qep->qepcon = intel_qep_readl(qep, INTEL_QEPCON);
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qep->qepflt = intel_qep_readl(qep, INTEL_QEPFLT);
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qep->qepmax = intel_qep_readl(qep, INTEL_QEPMAX);
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return 0;
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}
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static int __maybe_unused intel_qep_resume(struct device *dev)
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{
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struct pci_dev *pdev = to_pci_dev(dev);
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struct intel_qep *qep = pci_get_drvdata(pdev);
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/*
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* Make sure peripheral is disabled when restoring registers and
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* control register bits that are writable only when the peripheral
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* is disabled
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*/
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intel_qep_writel(qep, INTEL_QEPCON, 0);
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intel_qep_readl(qep, INTEL_QEPCON);
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intel_qep_writel(qep, INTEL_QEPFLT, qep->qepflt);
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intel_qep_writel(qep, INTEL_QEPMAX, qep->qepmax);
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intel_qep_writel(qep, INTEL_QEPINT_MASK, INTEL_QEPINT_MASK_ALL);
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/* Restore all other control register bits except enable status */
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intel_qep_writel(qep, INTEL_QEPCON, qep->qepcon & ~INTEL_QEPCON_EN);
|
|
intel_qep_readl(qep, INTEL_QEPCON);
|
|
|
|
/* Restore enable status */
|
|
intel_qep_writel(qep, INTEL_QEPCON, qep->qepcon);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static UNIVERSAL_DEV_PM_OPS(intel_qep_pm_ops,
|
|
intel_qep_suspend, intel_qep_resume, NULL);
|
|
|
|
static const struct pci_device_id intel_qep_id_table[] = {
|
|
/* EHL */
|
|
{ PCI_VDEVICE(INTEL, 0x4bc3), },
|
|
{ PCI_VDEVICE(INTEL, 0x4b81), },
|
|
{ PCI_VDEVICE(INTEL, 0x4b82), },
|
|
{ PCI_VDEVICE(INTEL, 0x4b83), },
|
|
{ } /* Terminating Entry */
|
|
};
|
|
MODULE_DEVICE_TABLE(pci, intel_qep_id_table);
|
|
|
|
static struct pci_driver intel_qep_driver = {
|
|
.name = "intel-qep",
|
|
.id_table = intel_qep_id_table,
|
|
.probe = intel_qep_probe,
|
|
.remove = intel_qep_remove,
|
|
.driver = {
|
|
.pm = &intel_qep_pm_ops,
|
|
}
|
|
};
|
|
|
|
module_pci_driver(intel_qep_driver);
|
|
|
|
MODULE_AUTHOR("Felipe Balbi (Intel)");
|
|
MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@linux.intel.com>");
|
|
MODULE_AUTHOR("Raymond Tan <raymond.tan@intel.com>");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_DESCRIPTION("Intel Quadrature Encoder Peripheral driver");
|
|
MODULE_IMPORT_NS(COUNTER);
|