162306a36Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0-or-later 262306a36Sopenharmony_ci/* 362306a36Sopenharmony_ci * Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com> 462306a36Sopenharmony_ci */ 562306a36Sopenharmony_ci 662306a36Sopenharmony_ci#include <linux/clk.h> 762306a36Sopenharmony_ci#include <linux/i2c.h> 862306a36Sopenharmony_ci#include <linux/iopoll.h> 962306a36Sopenharmony_ci#include <linux/interrupt.h> 1062306a36Sopenharmony_ci#include <linux/io.h> 1162306a36Sopenharmony_ci#include <linux/module.h> 1262306a36Sopenharmony_ci#include <linux/platform_device.h> 1362306a36Sopenharmony_ci 1462306a36Sopenharmony_ci#define UNIPHIER_FI2C_CR 0x00 /* control register */ 1562306a36Sopenharmony_ci#define UNIPHIER_FI2C_CR_MST BIT(3) /* master mode */ 1662306a36Sopenharmony_ci#define UNIPHIER_FI2C_CR_STA BIT(2) /* start condition */ 1762306a36Sopenharmony_ci#define UNIPHIER_FI2C_CR_STO BIT(1) /* stop condition */ 1862306a36Sopenharmony_ci#define UNIPHIER_FI2C_CR_NACK BIT(0) /* do not return ACK */ 1962306a36Sopenharmony_ci#define UNIPHIER_FI2C_DTTX 0x04 /* TX FIFO */ 2062306a36Sopenharmony_ci#define UNIPHIER_FI2C_DTTX_CMD BIT(8) /* send command (slave addr) */ 2162306a36Sopenharmony_ci#define UNIPHIER_FI2C_DTTX_RD BIT(0) /* read transaction */ 2262306a36Sopenharmony_ci#define UNIPHIER_FI2C_DTRX 0x04 /* RX FIFO */ 2362306a36Sopenharmony_ci#define UNIPHIER_FI2C_SLAD 0x0c /* slave address */ 2462306a36Sopenharmony_ci#define UNIPHIER_FI2C_CYC 0x10 /* clock cycle control */ 2562306a36Sopenharmony_ci#define UNIPHIER_FI2C_LCTL 0x14 /* clock low period control */ 2662306a36Sopenharmony_ci#define UNIPHIER_FI2C_SSUT 0x18 /* restart/stop setup time control */ 2762306a36Sopenharmony_ci#define UNIPHIER_FI2C_DSUT 0x1c /* data setup time control */ 2862306a36Sopenharmony_ci#define UNIPHIER_FI2C_INT 0x20 /* interrupt status */ 2962306a36Sopenharmony_ci#define UNIPHIER_FI2C_IE 0x24 /* interrupt enable */ 3062306a36Sopenharmony_ci#define UNIPHIER_FI2C_IC 0x28 /* interrupt clear */ 3162306a36Sopenharmony_ci#define UNIPHIER_FI2C_INT_TE BIT(9) /* TX FIFO empty */ 3262306a36Sopenharmony_ci#define UNIPHIER_FI2C_INT_RF BIT(8) /* RX FIFO full */ 3362306a36Sopenharmony_ci#define UNIPHIER_FI2C_INT_TC BIT(7) /* send complete (STOP) */ 3462306a36Sopenharmony_ci#define UNIPHIER_FI2C_INT_RC BIT(6) /* receive complete (STOP) */ 3562306a36Sopenharmony_ci#define UNIPHIER_FI2C_INT_TB BIT(5) /* sent specified bytes */ 3662306a36Sopenharmony_ci#define UNIPHIER_FI2C_INT_RB BIT(4) /* received specified bytes */ 3762306a36Sopenharmony_ci#define UNIPHIER_FI2C_INT_NA BIT(2) /* no ACK */ 3862306a36Sopenharmony_ci#define UNIPHIER_FI2C_INT_AL BIT(1) /* arbitration lost */ 3962306a36Sopenharmony_ci#define UNIPHIER_FI2C_SR 0x2c /* status register */ 4062306a36Sopenharmony_ci#define UNIPHIER_FI2C_SR_DB BIT(12) /* device busy */ 4162306a36Sopenharmony_ci#define UNIPHIER_FI2C_SR_STS BIT(11) /* stop condition detected */ 4262306a36Sopenharmony_ci#define UNIPHIER_FI2C_SR_BB BIT(8) /* bus busy */ 4362306a36Sopenharmony_ci#define UNIPHIER_FI2C_SR_RFF BIT(3) /* RX FIFO full */ 4462306a36Sopenharmony_ci#define UNIPHIER_FI2C_SR_RNE BIT(2) /* RX FIFO not empty */ 4562306a36Sopenharmony_ci#define UNIPHIER_FI2C_SR_TNF BIT(1) /* TX FIFO not full */ 4662306a36Sopenharmony_ci#define UNIPHIER_FI2C_SR_TFE BIT(0) /* TX FIFO empty */ 4762306a36Sopenharmony_ci#define UNIPHIER_FI2C_RST 0x34 /* reset control */ 4862306a36Sopenharmony_ci#define UNIPHIER_FI2C_RST_TBRST BIT(2) /* clear TX FIFO */ 4962306a36Sopenharmony_ci#define UNIPHIER_FI2C_RST_RBRST BIT(1) /* clear RX FIFO */ 5062306a36Sopenharmony_ci#define UNIPHIER_FI2C_RST_RST BIT(0) /* forcible bus reset */ 5162306a36Sopenharmony_ci#define UNIPHIER_FI2C_BM 0x38 /* bus monitor */ 5262306a36Sopenharmony_ci#define UNIPHIER_FI2C_BM_SDAO BIT(3) /* output for SDA line */ 5362306a36Sopenharmony_ci#define UNIPHIER_FI2C_BM_SDAS BIT(2) /* readback of SDA line */ 5462306a36Sopenharmony_ci#define UNIPHIER_FI2C_BM_SCLO BIT(1) /* output for SCL line */ 5562306a36Sopenharmony_ci#define UNIPHIER_FI2C_BM_SCLS BIT(0) /* readback of SCL line */ 5662306a36Sopenharmony_ci#define UNIPHIER_FI2C_NOISE 0x3c /* noise filter control */ 5762306a36Sopenharmony_ci#define UNIPHIER_FI2C_TBC 0x40 /* TX byte count setting */ 5862306a36Sopenharmony_ci#define UNIPHIER_FI2C_RBC 0x44 /* RX byte count setting */ 5962306a36Sopenharmony_ci#define UNIPHIER_FI2C_TBCM 0x48 /* TX byte count monitor */ 6062306a36Sopenharmony_ci#define UNIPHIER_FI2C_RBCM 0x4c /* RX byte count monitor */ 6162306a36Sopenharmony_ci#define UNIPHIER_FI2C_BRST 0x50 /* bus reset */ 6262306a36Sopenharmony_ci#define UNIPHIER_FI2C_BRST_FOEN BIT(1) /* normal operation */ 6362306a36Sopenharmony_ci#define UNIPHIER_FI2C_BRST_RSCL BIT(0) /* release SCL */ 6462306a36Sopenharmony_ci 6562306a36Sopenharmony_ci#define UNIPHIER_FI2C_INT_FAULTS \ 6662306a36Sopenharmony_ci (UNIPHIER_FI2C_INT_NA | UNIPHIER_FI2C_INT_AL) 6762306a36Sopenharmony_ci#define UNIPHIER_FI2C_INT_STOP \ 6862306a36Sopenharmony_ci (UNIPHIER_FI2C_INT_TC | UNIPHIER_FI2C_INT_RC) 6962306a36Sopenharmony_ci 7062306a36Sopenharmony_ci#define UNIPHIER_FI2C_RD BIT(0) 7162306a36Sopenharmony_ci#define UNIPHIER_FI2C_STOP BIT(1) 7262306a36Sopenharmony_ci#define UNIPHIER_FI2C_MANUAL_NACK BIT(2) 7362306a36Sopenharmony_ci#define UNIPHIER_FI2C_BYTE_WISE BIT(3) 7462306a36Sopenharmony_ci#define UNIPHIER_FI2C_DEFER_STOP_COMP BIT(4) 7562306a36Sopenharmony_ci 7662306a36Sopenharmony_ci#define UNIPHIER_FI2C_FIFO_SIZE 8 7762306a36Sopenharmony_ci 7862306a36Sopenharmony_cistruct uniphier_fi2c_priv { 7962306a36Sopenharmony_ci struct completion comp; 8062306a36Sopenharmony_ci struct i2c_adapter adap; 8162306a36Sopenharmony_ci void __iomem *membase; 8262306a36Sopenharmony_ci struct clk *clk; 8362306a36Sopenharmony_ci unsigned int len; 8462306a36Sopenharmony_ci u8 *buf; 8562306a36Sopenharmony_ci u32 enabled_irqs; 8662306a36Sopenharmony_ci int error; 8762306a36Sopenharmony_ci unsigned int flags; 8862306a36Sopenharmony_ci unsigned int busy_cnt; 8962306a36Sopenharmony_ci unsigned int clk_cycle; 9062306a36Sopenharmony_ci spinlock_t lock; /* IRQ synchronization */ 9162306a36Sopenharmony_ci}; 9262306a36Sopenharmony_ci 9362306a36Sopenharmony_cistatic void uniphier_fi2c_fill_txfifo(struct uniphier_fi2c_priv *priv, 9462306a36Sopenharmony_ci bool first) 9562306a36Sopenharmony_ci{ 9662306a36Sopenharmony_ci int fifo_space = UNIPHIER_FI2C_FIFO_SIZE; 9762306a36Sopenharmony_ci 9862306a36Sopenharmony_ci /* 9962306a36Sopenharmony_ci * TX-FIFO stores slave address in it for the first access. 10062306a36Sopenharmony_ci * Decrement the counter. 10162306a36Sopenharmony_ci */ 10262306a36Sopenharmony_ci if (first) 10362306a36Sopenharmony_ci fifo_space--; 10462306a36Sopenharmony_ci 10562306a36Sopenharmony_ci while (priv->len) { 10662306a36Sopenharmony_ci if (fifo_space-- <= 0) 10762306a36Sopenharmony_ci break; 10862306a36Sopenharmony_ci 10962306a36Sopenharmony_ci writel(*priv->buf++, priv->membase + UNIPHIER_FI2C_DTTX); 11062306a36Sopenharmony_ci priv->len--; 11162306a36Sopenharmony_ci } 11262306a36Sopenharmony_ci} 11362306a36Sopenharmony_ci 11462306a36Sopenharmony_cistatic void uniphier_fi2c_drain_rxfifo(struct uniphier_fi2c_priv *priv) 11562306a36Sopenharmony_ci{ 11662306a36Sopenharmony_ci int fifo_left = priv->flags & UNIPHIER_FI2C_BYTE_WISE ? 11762306a36Sopenharmony_ci 1 : UNIPHIER_FI2C_FIFO_SIZE; 11862306a36Sopenharmony_ci 11962306a36Sopenharmony_ci while (priv->len) { 12062306a36Sopenharmony_ci if (fifo_left-- <= 0) 12162306a36Sopenharmony_ci break; 12262306a36Sopenharmony_ci 12362306a36Sopenharmony_ci *priv->buf++ = readl(priv->membase + UNIPHIER_FI2C_DTRX); 12462306a36Sopenharmony_ci priv->len--; 12562306a36Sopenharmony_ci } 12662306a36Sopenharmony_ci} 12762306a36Sopenharmony_ci 12862306a36Sopenharmony_cistatic void uniphier_fi2c_set_irqs(struct uniphier_fi2c_priv *priv) 12962306a36Sopenharmony_ci{ 13062306a36Sopenharmony_ci writel(priv->enabled_irqs, priv->membase + UNIPHIER_FI2C_IE); 13162306a36Sopenharmony_ci} 13262306a36Sopenharmony_ci 13362306a36Sopenharmony_cistatic void uniphier_fi2c_clear_irqs(struct uniphier_fi2c_priv *priv, 13462306a36Sopenharmony_ci u32 mask) 13562306a36Sopenharmony_ci{ 13662306a36Sopenharmony_ci writel(mask, priv->membase + UNIPHIER_FI2C_IC); 13762306a36Sopenharmony_ci} 13862306a36Sopenharmony_ci 13962306a36Sopenharmony_cistatic void uniphier_fi2c_stop(struct uniphier_fi2c_priv *priv) 14062306a36Sopenharmony_ci{ 14162306a36Sopenharmony_ci priv->enabled_irqs |= UNIPHIER_FI2C_INT_STOP; 14262306a36Sopenharmony_ci uniphier_fi2c_set_irqs(priv); 14362306a36Sopenharmony_ci writel(UNIPHIER_FI2C_CR_MST | UNIPHIER_FI2C_CR_STO, 14462306a36Sopenharmony_ci priv->membase + UNIPHIER_FI2C_CR); 14562306a36Sopenharmony_ci} 14662306a36Sopenharmony_ci 14762306a36Sopenharmony_cistatic irqreturn_t uniphier_fi2c_interrupt(int irq, void *dev_id) 14862306a36Sopenharmony_ci{ 14962306a36Sopenharmony_ci struct uniphier_fi2c_priv *priv = dev_id; 15062306a36Sopenharmony_ci u32 irq_status; 15162306a36Sopenharmony_ci 15262306a36Sopenharmony_ci spin_lock(&priv->lock); 15362306a36Sopenharmony_ci 15462306a36Sopenharmony_ci irq_status = readl(priv->membase + UNIPHIER_FI2C_INT); 15562306a36Sopenharmony_ci irq_status &= priv->enabled_irqs; 15662306a36Sopenharmony_ci 15762306a36Sopenharmony_ci if (irq_status & UNIPHIER_FI2C_INT_STOP) 15862306a36Sopenharmony_ci goto complete; 15962306a36Sopenharmony_ci 16062306a36Sopenharmony_ci if (unlikely(irq_status & UNIPHIER_FI2C_INT_AL)) { 16162306a36Sopenharmony_ci priv->error = -EAGAIN; 16262306a36Sopenharmony_ci goto complete; 16362306a36Sopenharmony_ci } 16462306a36Sopenharmony_ci 16562306a36Sopenharmony_ci if (unlikely(irq_status & UNIPHIER_FI2C_INT_NA)) { 16662306a36Sopenharmony_ci priv->error = -ENXIO; 16762306a36Sopenharmony_ci if (priv->flags & UNIPHIER_FI2C_RD) { 16862306a36Sopenharmony_ci /* 16962306a36Sopenharmony_ci * work around a hardware bug: 17062306a36Sopenharmony_ci * The receive-completed interrupt is never set even if 17162306a36Sopenharmony_ci * STOP condition is detected after the address phase 17262306a36Sopenharmony_ci * of read transaction fails to get ACK. 17362306a36Sopenharmony_ci * To avoid time-out error, we issue STOP here, 17462306a36Sopenharmony_ci * but do not wait for its completion. 17562306a36Sopenharmony_ci * It should be checked after exiting this handler. 17662306a36Sopenharmony_ci */ 17762306a36Sopenharmony_ci uniphier_fi2c_stop(priv); 17862306a36Sopenharmony_ci priv->flags |= UNIPHIER_FI2C_DEFER_STOP_COMP; 17962306a36Sopenharmony_ci goto complete; 18062306a36Sopenharmony_ci } 18162306a36Sopenharmony_ci goto stop; 18262306a36Sopenharmony_ci } 18362306a36Sopenharmony_ci 18462306a36Sopenharmony_ci if (irq_status & UNIPHIER_FI2C_INT_TE) { 18562306a36Sopenharmony_ci if (!priv->len) 18662306a36Sopenharmony_ci goto data_done; 18762306a36Sopenharmony_ci 18862306a36Sopenharmony_ci uniphier_fi2c_fill_txfifo(priv, false); 18962306a36Sopenharmony_ci goto handled; 19062306a36Sopenharmony_ci } 19162306a36Sopenharmony_ci 19262306a36Sopenharmony_ci if (irq_status & (UNIPHIER_FI2C_INT_RF | UNIPHIER_FI2C_INT_RB)) { 19362306a36Sopenharmony_ci uniphier_fi2c_drain_rxfifo(priv); 19462306a36Sopenharmony_ci /* 19562306a36Sopenharmony_ci * If the number of bytes to read is multiple of the FIFO size 19662306a36Sopenharmony_ci * (msg->len == 8, 16, 24, ...), the INT_RF bit is set a little 19762306a36Sopenharmony_ci * earlier than INT_RB. We wait for INT_RB to confirm the 19862306a36Sopenharmony_ci * completion of the current message. 19962306a36Sopenharmony_ci */ 20062306a36Sopenharmony_ci if (!priv->len && (irq_status & UNIPHIER_FI2C_INT_RB)) 20162306a36Sopenharmony_ci goto data_done; 20262306a36Sopenharmony_ci 20362306a36Sopenharmony_ci if (unlikely(priv->flags & UNIPHIER_FI2C_MANUAL_NACK)) { 20462306a36Sopenharmony_ci if (priv->len <= UNIPHIER_FI2C_FIFO_SIZE && 20562306a36Sopenharmony_ci !(priv->flags & UNIPHIER_FI2C_BYTE_WISE)) { 20662306a36Sopenharmony_ci priv->enabled_irqs |= UNIPHIER_FI2C_INT_RB; 20762306a36Sopenharmony_ci uniphier_fi2c_set_irqs(priv); 20862306a36Sopenharmony_ci priv->flags |= UNIPHIER_FI2C_BYTE_WISE; 20962306a36Sopenharmony_ci } 21062306a36Sopenharmony_ci if (priv->len <= 1) 21162306a36Sopenharmony_ci writel(UNIPHIER_FI2C_CR_MST | 21262306a36Sopenharmony_ci UNIPHIER_FI2C_CR_NACK, 21362306a36Sopenharmony_ci priv->membase + UNIPHIER_FI2C_CR); 21462306a36Sopenharmony_ci } 21562306a36Sopenharmony_ci 21662306a36Sopenharmony_ci goto handled; 21762306a36Sopenharmony_ci } 21862306a36Sopenharmony_ci 21962306a36Sopenharmony_ci spin_unlock(&priv->lock); 22062306a36Sopenharmony_ci 22162306a36Sopenharmony_ci return IRQ_NONE; 22262306a36Sopenharmony_ci 22362306a36Sopenharmony_cidata_done: 22462306a36Sopenharmony_ci if (priv->flags & UNIPHIER_FI2C_STOP) { 22562306a36Sopenharmony_cistop: 22662306a36Sopenharmony_ci uniphier_fi2c_stop(priv); 22762306a36Sopenharmony_ci } else { 22862306a36Sopenharmony_cicomplete: 22962306a36Sopenharmony_ci priv->enabled_irqs = 0; 23062306a36Sopenharmony_ci uniphier_fi2c_set_irqs(priv); 23162306a36Sopenharmony_ci complete(&priv->comp); 23262306a36Sopenharmony_ci } 23362306a36Sopenharmony_ci 23462306a36Sopenharmony_cihandled: 23562306a36Sopenharmony_ci /* 23662306a36Sopenharmony_ci * This controller makes a pause while any bit of the IRQ status is 23762306a36Sopenharmony_ci * asserted. Clear the asserted bit to kick the controller just before 23862306a36Sopenharmony_ci * exiting the handler. 23962306a36Sopenharmony_ci */ 24062306a36Sopenharmony_ci uniphier_fi2c_clear_irqs(priv, irq_status); 24162306a36Sopenharmony_ci 24262306a36Sopenharmony_ci spin_unlock(&priv->lock); 24362306a36Sopenharmony_ci 24462306a36Sopenharmony_ci return IRQ_HANDLED; 24562306a36Sopenharmony_ci} 24662306a36Sopenharmony_ci 24762306a36Sopenharmony_cistatic void uniphier_fi2c_tx_init(struct uniphier_fi2c_priv *priv, u16 addr, 24862306a36Sopenharmony_ci bool repeat) 24962306a36Sopenharmony_ci{ 25062306a36Sopenharmony_ci priv->enabled_irqs |= UNIPHIER_FI2C_INT_TE; 25162306a36Sopenharmony_ci uniphier_fi2c_set_irqs(priv); 25262306a36Sopenharmony_ci 25362306a36Sopenharmony_ci /* do not use TX byte counter */ 25462306a36Sopenharmony_ci writel(0, priv->membase + UNIPHIER_FI2C_TBC); 25562306a36Sopenharmony_ci /* set slave address */ 25662306a36Sopenharmony_ci writel(UNIPHIER_FI2C_DTTX_CMD | addr << 1, 25762306a36Sopenharmony_ci priv->membase + UNIPHIER_FI2C_DTTX); 25862306a36Sopenharmony_ci /* 25962306a36Sopenharmony_ci * First chunk of data. For a repeated START condition, do not write 26062306a36Sopenharmony_ci * data to the TX fifo here to avoid the timing issue. 26162306a36Sopenharmony_ci */ 26262306a36Sopenharmony_ci if (!repeat) 26362306a36Sopenharmony_ci uniphier_fi2c_fill_txfifo(priv, true); 26462306a36Sopenharmony_ci} 26562306a36Sopenharmony_ci 26662306a36Sopenharmony_cistatic void uniphier_fi2c_rx_init(struct uniphier_fi2c_priv *priv, u16 addr) 26762306a36Sopenharmony_ci{ 26862306a36Sopenharmony_ci priv->flags |= UNIPHIER_FI2C_RD; 26962306a36Sopenharmony_ci 27062306a36Sopenharmony_ci if (likely(priv->len < 256)) { 27162306a36Sopenharmony_ci /* 27262306a36Sopenharmony_ci * If possible, use RX byte counter. 27362306a36Sopenharmony_ci * It can automatically handle NACK for the last byte. 27462306a36Sopenharmony_ci */ 27562306a36Sopenharmony_ci writel(priv->len, priv->membase + UNIPHIER_FI2C_RBC); 27662306a36Sopenharmony_ci priv->enabled_irqs |= UNIPHIER_FI2C_INT_RF | 27762306a36Sopenharmony_ci UNIPHIER_FI2C_INT_RB; 27862306a36Sopenharmony_ci } else { 27962306a36Sopenharmony_ci /* 28062306a36Sopenharmony_ci * The byte counter can not count over 256. In this case, 28162306a36Sopenharmony_ci * do not use it at all. Drain data when FIFO gets full, 28262306a36Sopenharmony_ci * but treat the last portion as a special case. 28362306a36Sopenharmony_ci */ 28462306a36Sopenharmony_ci writel(0, priv->membase + UNIPHIER_FI2C_RBC); 28562306a36Sopenharmony_ci priv->flags |= UNIPHIER_FI2C_MANUAL_NACK; 28662306a36Sopenharmony_ci priv->enabled_irqs |= UNIPHIER_FI2C_INT_RF; 28762306a36Sopenharmony_ci } 28862306a36Sopenharmony_ci 28962306a36Sopenharmony_ci uniphier_fi2c_set_irqs(priv); 29062306a36Sopenharmony_ci 29162306a36Sopenharmony_ci /* set slave address with RD bit */ 29262306a36Sopenharmony_ci writel(UNIPHIER_FI2C_DTTX_CMD | UNIPHIER_FI2C_DTTX_RD | addr << 1, 29362306a36Sopenharmony_ci priv->membase + UNIPHIER_FI2C_DTTX); 29462306a36Sopenharmony_ci} 29562306a36Sopenharmony_ci 29662306a36Sopenharmony_cistatic void uniphier_fi2c_reset(struct uniphier_fi2c_priv *priv) 29762306a36Sopenharmony_ci{ 29862306a36Sopenharmony_ci writel(UNIPHIER_FI2C_RST_RST, priv->membase + UNIPHIER_FI2C_RST); 29962306a36Sopenharmony_ci} 30062306a36Sopenharmony_ci 30162306a36Sopenharmony_cistatic void uniphier_fi2c_prepare_operation(struct uniphier_fi2c_priv *priv) 30262306a36Sopenharmony_ci{ 30362306a36Sopenharmony_ci writel(UNIPHIER_FI2C_BRST_FOEN | UNIPHIER_FI2C_BRST_RSCL, 30462306a36Sopenharmony_ci priv->membase + UNIPHIER_FI2C_BRST); 30562306a36Sopenharmony_ci} 30662306a36Sopenharmony_ci 30762306a36Sopenharmony_cistatic void uniphier_fi2c_recover(struct uniphier_fi2c_priv *priv) 30862306a36Sopenharmony_ci{ 30962306a36Sopenharmony_ci uniphier_fi2c_reset(priv); 31062306a36Sopenharmony_ci i2c_recover_bus(&priv->adap); 31162306a36Sopenharmony_ci} 31262306a36Sopenharmony_ci 31362306a36Sopenharmony_cistatic int uniphier_fi2c_master_xfer_one(struct i2c_adapter *adap, 31462306a36Sopenharmony_ci struct i2c_msg *msg, bool repeat, 31562306a36Sopenharmony_ci bool stop) 31662306a36Sopenharmony_ci{ 31762306a36Sopenharmony_ci struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap); 31862306a36Sopenharmony_ci bool is_read = msg->flags & I2C_M_RD; 31962306a36Sopenharmony_ci unsigned long time_left, flags; 32062306a36Sopenharmony_ci 32162306a36Sopenharmony_ci priv->len = msg->len; 32262306a36Sopenharmony_ci priv->buf = msg->buf; 32362306a36Sopenharmony_ci priv->enabled_irqs = UNIPHIER_FI2C_INT_FAULTS; 32462306a36Sopenharmony_ci priv->error = 0; 32562306a36Sopenharmony_ci priv->flags = 0; 32662306a36Sopenharmony_ci 32762306a36Sopenharmony_ci if (stop) 32862306a36Sopenharmony_ci priv->flags |= UNIPHIER_FI2C_STOP; 32962306a36Sopenharmony_ci 33062306a36Sopenharmony_ci reinit_completion(&priv->comp); 33162306a36Sopenharmony_ci uniphier_fi2c_clear_irqs(priv, U32_MAX); 33262306a36Sopenharmony_ci writel(UNIPHIER_FI2C_RST_TBRST | UNIPHIER_FI2C_RST_RBRST, 33362306a36Sopenharmony_ci priv->membase + UNIPHIER_FI2C_RST); /* reset TX/RX FIFO */ 33462306a36Sopenharmony_ci 33562306a36Sopenharmony_ci spin_lock_irqsave(&priv->lock, flags); 33662306a36Sopenharmony_ci 33762306a36Sopenharmony_ci if (is_read) 33862306a36Sopenharmony_ci uniphier_fi2c_rx_init(priv, msg->addr); 33962306a36Sopenharmony_ci else 34062306a36Sopenharmony_ci uniphier_fi2c_tx_init(priv, msg->addr, repeat); 34162306a36Sopenharmony_ci 34262306a36Sopenharmony_ci /* 34362306a36Sopenharmony_ci * For a repeated START condition, writing a slave address to the FIFO 34462306a36Sopenharmony_ci * kicks the controller. So, the UNIPHIER_FI2C_CR register should be 34562306a36Sopenharmony_ci * written only for a non-repeated START condition. 34662306a36Sopenharmony_ci */ 34762306a36Sopenharmony_ci if (!repeat) 34862306a36Sopenharmony_ci writel(UNIPHIER_FI2C_CR_MST | UNIPHIER_FI2C_CR_STA, 34962306a36Sopenharmony_ci priv->membase + UNIPHIER_FI2C_CR); 35062306a36Sopenharmony_ci 35162306a36Sopenharmony_ci spin_unlock_irqrestore(&priv->lock, flags); 35262306a36Sopenharmony_ci 35362306a36Sopenharmony_ci time_left = wait_for_completion_timeout(&priv->comp, adap->timeout); 35462306a36Sopenharmony_ci 35562306a36Sopenharmony_ci spin_lock_irqsave(&priv->lock, flags); 35662306a36Sopenharmony_ci priv->enabled_irqs = 0; 35762306a36Sopenharmony_ci uniphier_fi2c_set_irqs(priv); 35862306a36Sopenharmony_ci spin_unlock_irqrestore(&priv->lock, flags); 35962306a36Sopenharmony_ci 36062306a36Sopenharmony_ci if (!time_left) { 36162306a36Sopenharmony_ci dev_err(&adap->dev, "transaction timeout.\n"); 36262306a36Sopenharmony_ci uniphier_fi2c_recover(priv); 36362306a36Sopenharmony_ci return -ETIMEDOUT; 36462306a36Sopenharmony_ci } 36562306a36Sopenharmony_ci 36662306a36Sopenharmony_ci if (unlikely(priv->flags & UNIPHIER_FI2C_DEFER_STOP_COMP)) { 36762306a36Sopenharmony_ci u32 status; 36862306a36Sopenharmony_ci int ret; 36962306a36Sopenharmony_ci 37062306a36Sopenharmony_ci ret = readl_poll_timeout(priv->membase + UNIPHIER_FI2C_SR, 37162306a36Sopenharmony_ci status, 37262306a36Sopenharmony_ci (status & UNIPHIER_FI2C_SR_STS) && 37362306a36Sopenharmony_ci !(status & UNIPHIER_FI2C_SR_BB), 37462306a36Sopenharmony_ci 1, 20); 37562306a36Sopenharmony_ci if (ret) { 37662306a36Sopenharmony_ci dev_err(&adap->dev, 37762306a36Sopenharmony_ci "stop condition was not completed.\n"); 37862306a36Sopenharmony_ci uniphier_fi2c_recover(priv); 37962306a36Sopenharmony_ci return ret; 38062306a36Sopenharmony_ci } 38162306a36Sopenharmony_ci } 38262306a36Sopenharmony_ci 38362306a36Sopenharmony_ci return priv->error; 38462306a36Sopenharmony_ci} 38562306a36Sopenharmony_ci 38662306a36Sopenharmony_cistatic int uniphier_fi2c_check_bus_busy(struct i2c_adapter *adap) 38762306a36Sopenharmony_ci{ 38862306a36Sopenharmony_ci struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap); 38962306a36Sopenharmony_ci 39062306a36Sopenharmony_ci if (readl(priv->membase + UNIPHIER_FI2C_SR) & UNIPHIER_FI2C_SR_DB) { 39162306a36Sopenharmony_ci if (priv->busy_cnt++ > 3) { 39262306a36Sopenharmony_ci /* 39362306a36Sopenharmony_ci * If bus busy continues too long, it is probably 39462306a36Sopenharmony_ci * in a wrong state. Try bus recovery. 39562306a36Sopenharmony_ci */ 39662306a36Sopenharmony_ci uniphier_fi2c_recover(priv); 39762306a36Sopenharmony_ci priv->busy_cnt = 0; 39862306a36Sopenharmony_ci } 39962306a36Sopenharmony_ci 40062306a36Sopenharmony_ci return -EAGAIN; 40162306a36Sopenharmony_ci } 40262306a36Sopenharmony_ci 40362306a36Sopenharmony_ci priv->busy_cnt = 0; 40462306a36Sopenharmony_ci return 0; 40562306a36Sopenharmony_ci} 40662306a36Sopenharmony_ci 40762306a36Sopenharmony_cistatic int uniphier_fi2c_master_xfer(struct i2c_adapter *adap, 40862306a36Sopenharmony_ci struct i2c_msg *msgs, int num) 40962306a36Sopenharmony_ci{ 41062306a36Sopenharmony_ci struct i2c_msg *msg, *emsg = msgs + num; 41162306a36Sopenharmony_ci bool repeat = false; 41262306a36Sopenharmony_ci int ret; 41362306a36Sopenharmony_ci 41462306a36Sopenharmony_ci ret = uniphier_fi2c_check_bus_busy(adap); 41562306a36Sopenharmony_ci if (ret) 41662306a36Sopenharmony_ci return ret; 41762306a36Sopenharmony_ci 41862306a36Sopenharmony_ci for (msg = msgs; msg < emsg; msg++) { 41962306a36Sopenharmony_ci /* Emit STOP if it is the last message or I2C_M_STOP is set. */ 42062306a36Sopenharmony_ci bool stop = (msg + 1 == emsg) || (msg->flags & I2C_M_STOP); 42162306a36Sopenharmony_ci 42262306a36Sopenharmony_ci ret = uniphier_fi2c_master_xfer_one(adap, msg, repeat, stop); 42362306a36Sopenharmony_ci if (ret) 42462306a36Sopenharmony_ci return ret; 42562306a36Sopenharmony_ci 42662306a36Sopenharmony_ci repeat = !stop; 42762306a36Sopenharmony_ci } 42862306a36Sopenharmony_ci 42962306a36Sopenharmony_ci return num; 43062306a36Sopenharmony_ci} 43162306a36Sopenharmony_ci 43262306a36Sopenharmony_cistatic u32 uniphier_fi2c_functionality(struct i2c_adapter *adap) 43362306a36Sopenharmony_ci{ 43462306a36Sopenharmony_ci return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; 43562306a36Sopenharmony_ci} 43662306a36Sopenharmony_ci 43762306a36Sopenharmony_cistatic const struct i2c_algorithm uniphier_fi2c_algo = { 43862306a36Sopenharmony_ci .master_xfer = uniphier_fi2c_master_xfer, 43962306a36Sopenharmony_ci .functionality = uniphier_fi2c_functionality, 44062306a36Sopenharmony_ci}; 44162306a36Sopenharmony_ci 44262306a36Sopenharmony_cistatic int uniphier_fi2c_get_scl(struct i2c_adapter *adap) 44362306a36Sopenharmony_ci{ 44462306a36Sopenharmony_ci struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap); 44562306a36Sopenharmony_ci 44662306a36Sopenharmony_ci return !!(readl(priv->membase + UNIPHIER_FI2C_BM) & 44762306a36Sopenharmony_ci UNIPHIER_FI2C_BM_SCLS); 44862306a36Sopenharmony_ci} 44962306a36Sopenharmony_ci 45062306a36Sopenharmony_cistatic void uniphier_fi2c_set_scl(struct i2c_adapter *adap, int val) 45162306a36Sopenharmony_ci{ 45262306a36Sopenharmony_ci struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap); 45362306a36Sopenharmony_ci 45462306a36Sopenharmony_ci writel(val ? UNIPHIER_FI2C_BRST_RSCL : 0, 45562306a36Sopenharmony_ci priv->membase + UNIPHIER_FI2C_BRST); 45662306a36Sopenharmony_ci} 45762306a36Sopenharmony_ci 45862306a36Sopenharmony_cistatic int uniphier_fi2c_get_sda(struct i2c_adapter *adap) 45962306a36Sopenharmony_ci{ 46062306a36Sopenharmony_ci struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap); 46162306a36Sopenharmony_ci 46262306a36Sopenharmony_ci return !!(readl(priv->membase + UNIPHIER_FI2C_BM) & 46362306a36Sopenharmony_ci UNIPHIER_FI2C_BM_SDAS); 46462306a36Sopenharmony_ci} 46562306a36Sopenharmony_ci 46662306a36Sopenharmony_cistatic void uniphier_fi2c_unprepare_recovery(struct i2c_adapter *adap) 46762306a36Sopenharmony_ci{ 46862306a36Sopenharmony_ci uniphier_fi2c_prepare_operation(i2c_get_adapdata(adap)); 46962306a36Sopenharmony_ci} 47062306a36Sopenharmony_ci 47162306a36Sopenharmony_cistatic struct i2c_bus_recovery_info uniphier_fi2c_bus_recovery_info = { 47262306a36Sopenharmony_ci .recover_bus = i2c_generic_scl_recovery, 47362306a36Sopenharmony_ci .get_scl = uniphier_fi2c_get_scl, 47462306a36Sopenharmony_ci .set_scl = uniphier_fi2c_set_scl, 47562306a36Sopenharmony_ci .get_sda = uniphier_fi2c_get_sda, 47662306a36Sopenharmony_ci .unprepare_recovery = uniphier_fi2c_unprepare_recovery, 47762306a36Sopenharmony_ci}; 47862306a36Sopenharmony_ci 47962306a36Sopenharmony_cistatic void uniphier_fi2c_hw_init(struct uniphier_fi2c_priv *priv) 48062306a36Sopenharmony_ci{ 48162306a36Sopenharmony_ci unsigned int cyc = priv->clk_cycle; 48262306a36Sopenharmony_ci u32 tmp; 48362306a36Sopenharmony_ci 48462306a36Sopenharmony_ci tmp = readl(priv->membase + UNIPHIER_FI2C_CR); 48562306a36Sopenharmony_ci tmp |= UNIPHIER_FI2C_CR_MST; 48662306a36Sopenharmony_ci writel(tmp, priv->membase + UNIPHIER_FI2C_CR); 48762306a36Sopenharmony_ci 48862306a36Sopenharmony_ci uniphier_fi2c_reset(priv); 48962306a36Sopenharmony_ci 49062306a36Sopenharmony_ci /* 49162306a36Sopenharmony_ci * Standard-mode: tLOW + tHIGH = 10 us 49262306a36Sopenharmony_ci * Fast-mode: tLOW + tHIGH = 2.5 us 49362306a36Sopenharmony_ci */ 49462306a36Sopenharmony_ci writel(cyc, priv->membase + UNIPHIER_FI2C_CYC); 49562306a36Sopenharmony_ci /* 49662306a36Sopenharmony_ci * Standard-mode: tLOW = 4.7 us, tHIGH = 4.0 us, tBUF = 4.7 us 49762306a36Sopenharmony_ci * Fast-mode: tLOW = 1.3 us, tHIGH = 0.6 us, tBUF = 1.3 us 49862306a36Sopenharmony_ci * "tLow/tHIGH = 5/4" meets both. 49962306a36Sopenharmony_ci */ 50062306a36Sopenharmony_ci writel(cyc * 5 / 9, priv->membase + UNIPHIER_FI2C_LCTL); 50162306a36Sopenharmony_ci /* 50262306a36Sopenharmony_ci * Standard-mode: tHD;STA = 4.0 us, tSU;STA = 4.7 us, tSU;STO = 4.0 us 50362306a36Sopenharmony_ci * Fast-mode: tHD;STA = 0.6 us, tSU;STA = 0.6 us, tSU;STO = 0.6 us 50462306a36Sopenharmony_ci */ 50562306a36Sopenharmony_ci writel(cyc / 2, priv->membase + UNIPHIER_FI2C_SSUT); 50662306a36Sopenharmony_ci /* 50762306a36Sopenharmony_ci * Standard-mode: tSU;DAT = 250 ns 50862306a36Sopenharmony_ci * Fast-mode: tSU;DAT = 100 ns 50962306a36Sopenharmony_ci */ 51062306a36Sopenharmony_ci writel(cyc / 16, priv->membase + UNIPHIER_FI2C_DSUT); 51162306a36Sopenharmony_ci 51262306a36Sopenharmony_ci uniphier_fi2c_prepare_operation(priv); 51362306a36Sopenharmony_ci} 51462306a36Sopenharmony_ci 51562306a36Sopenharmony_cistatic int uniphier_fi2c_probe(struct platform_device *pdev) 51662306a36Sopenharmony_ci{ 51762306a36Sopenharmony_ci struct device *dev = &pdev->dev; 51862306a36Sopenharmony_ci struct uniphier_fi2c_priv *priv; 51962306a36Sopenharmony_ci u32 bus_speed; 52062306a36Sopenharmony_ci unsigned long clk_rate; 52162306a36Sopenharmony_ci int irq, ret; 52262306a36Sopenharmony_ci 52362306a36Sopenharmony_ci priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 52462306a36Sopenharmony_ci if (!priv) 52562306a36Sopenharmony_ci return -ENOMEM; 52662306a36Sopenharmony_ci 52762306a36Sopenharmony_ci priv->membase = devm_platform_ioremap_resource(pdev, 0); 52862306a36Sopenharmony_ci if (IS_ERR(priv->membase)) 52962306a36Sopenharmony_ci return PTR_ERR(priv->membase); 53062306a36Sopenharmony_ci 53162306a36Sopenharmony_ci irq = platform_get_irq(pdev, 0); 53262306a36Sopenharmony_ci if (irq < 0) 53362306a36Sopenharmony_ci return irq; 53462306a36Sopenharmony_ci 53562306a36Sopenharmony_ci if (of_property_read_u32(dev->of_node, "clock-frequency", &bus_speed)) 53662306a36Sopenharmony_ci bus_speed = I2C_MAX_STANDARD_MODE_FREQ; 53762306a36Sopenharmony_ci 53862306a36Sopenharmony_ci if (!bus_speed || bus_speed > I2C_MAX_FAST_MODE_FREQ) { 53962306a36Sopenharmony_ci dev_err(dev, "invalid clock-frequency %d\n", bus_speed); 54062306a36Sopenharmony_ci return -EINVAL; 54162306a36Sopenharmony_ci } 54262306a36Sopenharmony_ci 54362306a36Sopenharmony_ci priv->clk = devm_clk_get_enabled(dev, NULL); 54462306a36Sopenharmony_ci if (IS_ERR(priv->clk)) { 54562306a36Sopenharmony_ci dev_err(dev, "failed to enable clock\n"); 54662306a36Sopenharmony_ci return PTR_ERR(priv->clk); 54762306a36Sopenharmony_ci } 54862306a36Sopenharmony_ci 54962306a36Sopenharmony_ci clk_rate = clk_get_rate(priv->clk); 55062306a36Sopenharmony_ci if (!clk_rate) { 55162306a36Sopenharmony_ci dev_err(dev, "input clock rate should not be zero\n"); 55262306a36Sopenharmony_ci return -EINVAL; 55362306a36Sopenharmony_ci } 55462306a36Sopenharmony_ci 55562306a36Sopenharmony_ci priv->clk_cycle = clk_rate / bus_speed; 55662306a36Sopenharmony_ci init_completion(&priv->comp); 55762306a36Sopenharmony_ci spin_lock_init(&priv->lock); 55862306a36Sopenharmony_ci priv->adap.owner = THIS_MODULE; 55962306a36Sopenharmony_ci priv->adap.algo = &uniphier_fi2c_algo; 56062306a36Sopenharmony_ci priv->adap.dev.parent = dev; 56162306a36Sopenharmony_ci priv->adap.dev.of_node = dev->of_node; 56262306a36Sopenharmony_ci strscpy(priv->adap.name, "UniPhier FI2C", sizeof(priv->adap.name)); 56362306a36Sopenharmony_ci priv->adap.bus_recovery_info = &uniphier_fi2c_bus_recovery_info; 56462306a36Sopenharmony_ci i2c_set_adapdata(&priv->adap, priv); 56562306a36Sopenharmony_ci platform_set_drvdata(pdev, priv); 56662306a36Sopenharmony_ci 56762306a36Sopenharmony_ci uniphier_fi2c_hw_init(priv); 56862306a36Sopenharmony_ci 56962306a36Sopenharmony_ci ret = devm_request_irq(dev, irq, uniphier_fi2c_interrupt, 0, 57062306a36Sopenharmony_ci pdev->name, priv); 57162306a36Sopenharmony_ci if (ret) { 57262306a36Sopenharmony_ci dev_err(dev, "failed to request irq %d\n", irq); 57362306a36Sopenharmony_ci return ret; 57462306a36Sopenharmony_ci } 57562306a36Sopenharmony_ci 57662306a36Sopenharmony_ci return i2c_add_adapter(&priv->adap); 57762306a36Sopenharmony_ci} 57862306a36Sopenharmony_ci 57962306a36Sopenharmony_cistatic void uniphier_fi2c_remove(struct platform_device *pdev) 58062306a36Sopenharmony_ci{ 58162306a36Sopenharmony_ci struct uniphier_fi2c_priv *priv = platform_get_drvdata(pdev); 58262306a36Sopenharmony_ci 58362306a36Sopenharmony_ci i2c_del_adapter(&priv->adap); 58462306a36Sopenharmony_ci} 58562306a36Sopenharmony_ci 58662306a36Sopenharmony_cistatic int __maybe_unused uniphier_fi2c_suspend(struct device *dev) 58762306a36Sopenharmony_ci{ 58862306a36Sopenharmony_ci struct uniphier_fi2c_priv *priv = dev_get_drvdata(dev); 58962306a36Sopenharmony_ci 59062306a36Sopenharmony_ci clk_disable_unprepare(priv->clk); 59162306a36Sopenharmony_ci 59262306a36Sopenharmony_ci return 0; 59362306a36Sopenharmony_ci} 59462306a36Sopenharmony_ci 59562306a36Sopenharmony_cistatic int __maybe_unused uniphier_fi2c_resume(struct device *dev) 59662306a36Sopenharmony_ci{ 59762306a36Sopenharmony_ci struct uniphier_fi2c_priv *priv = dev_get_drvdata(dev); 59862306a36Sopenharmony_ci int ret; 59962306a36Sopenharmony_ci 60062306a36Sopenharmony_ci ret = clk_prepare_enable(priv->clk); 60162306a36Sopenharmony_ci if (ret) 60262306a36Sopenharmony_ci return ret; 60362306a36Sopenharmony_ci 60462306a36Sopenharmony_ci uniphier_fi2c_hw_init(priv); 60562306a36Sopenharmony_ci 60662306a36Sopenharmony_ci return 0; 60762306a36Sopenharmony_ci} 60862306a36Sopenharmony_ci 60962306a36Sopenharmony_cistatic const struct dev_pm_ops uniphier_fi2c_pm_ops = { 61062306a36Sopenharmony_ci SET_SYSTEM_SLEEP_PM_OPS(uniphier_fi2c_suspend, uniphier_fi2c_resume) 61162306a36Sopenharmony_ci}; 61262306a36Sopenharmony_ci 61362306a36Sopenharmony_cistatic const struct of_device_id uniphier_fi2c_match[] = { 61462306a36Sopenharmony_ci { .compatible = "socionext,uniphier-fi2c" }, 61562306a36Sopenharmony_ci { /* sentinel */ } 61662306a36Sopenharmony_ci}; 61762306a36Sopenharmony_ciMODULE_DEVICE_TABLE(of, uniphier_fi2c_match); 61862306a36Sopenharmony_ci 61962306a36Sopenharmony_cistatic struct platform_driver uniphier_fi2c_drv = { 62062306a36Sopenharmony_ci .probe = uniphier_fi2c_probe, 62162306a36Sopenharmony_ci .remove_new = uniphier_fi2c_remove, 62262306a36Sopenharmony_ci .driver = { 62362306a36Sopenharmony_ci .name = "uniphier-fi2c", 62462306a36Sopenharmony_ci .of_match_table = uniphier_fi2c_match, 62562306a36Sopenharmony_ci .pm = &uniphier_fi2c_pm_ops, 62662306a36Sopenharmony_ci }, 62762306a36Sopenharmony_ci}; 62862306a36Sopenharmony_cimodule_platform_driver(uniphier_fi2c_drv); 62962306a36Sopenharmony_ci 63062306a36Sopenharmony_ciMODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>"); 63162306a36Sopenharmony_ciMODULE_DESCRIPTION("UniPhier FIFO-builtin I2C bus driver"); 63262306a36Sopenharmony_ciMODULE_LICENSE("GPL"); 633