cregit-Linux how code gets into the kernel

Release 4.7 drivers/i2c/busses/i2c-sh_mobile.c

/*
 * SuperH Mobile I2C Controller
 *
 * Copyright (C) 2014 Wolfram Sang <wsa@sang-engineering.com>
 *
 * Copyright (C) 2008 Magnus Damm
 *
 * Portions of the code based on out-of-tree driver i2c-sh7343.c
 * Copyright (c) 2006 Carlos Munoz <carlos@kenati.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/i2c/i2c-sh_mobile.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>

/* Transmit operation:                                                      */
/*                                                                          */
/* 0 byte transmit                                                          */
/* BUS:     S     A8     ACK   P(*)                                         */
/* IRQ:       DTE   WAIT                                                    */
/* ICIC:                                                                    */
/* ICCR: 0x94 0x90                                                          */
/* ICDR:      A8                                                            */
/*                                                                          */
/* 1 byte transmit                                                          */
/* BUS:     S     A8     ACK   D8(1)   ACK   P(*)                           */
/* IRQ:       DTE   WAIT         WAIT                                       */
/* ICIC:      -DTE                                                          */
/* ICCR: 0x94       0x90                                                    */
/* ICDR:      A8    D8(1)                                                   */
/*                                                                          */
/* 2 byte transmit                                                          */
/* BUS:     S     A8     ACK   D8(1)   ACK   D8(2)   ACK   P(*)             */
/* IRQ:       DTE   WAIT         WAIT          WAIT                         */
/* ICIC:      -DTE                                                          */
/* ICCR: 0x94                    0x90                                       */
/* ICDR:      A8    D8(1)        D8(2)                                      */
/*                                                                          */
/* 3 bytes or more, +---------+ gets repeated                               */
/*                                                                          */
/*                                                                          */
/* Receive operation:                                                       */
/*                                                                          */
/* 0 byte receive - not supported since slave may hold SDA low              */
/*                                                                          */
/* 1 byte receive       [TX] | [RX]                                         */
/* BUS:     S     A8     ACK | D8(1)   ACK   P(*)                           */
/* IRQ:       DTE   WAIT     |   WAIT     DTE                               */
/* ICIC:      -DTE           |   +DTE                                       */
/* ICCR: 0x94       0x81     |   0xc0                                       */
/* ICDR:      A8             |            D8(1)                             */
/*                                                                          */
/* 2 byte receive        [TX]| [RX]                                         */
/* BUS:     S     A8     ACK | D8(1)   ACK   D8(2)   ACK   P(*)             */
/* IRQ:       DTE   WAIT     |   WAIT          WAIT     DTE                 */
/* ICIC:      -DTE           |                 +DTE                         */
/* ICCR: 0x94       0x81     |                 0xc0                         */
/* ICDR:      A8             |                 D8(1)    D8(2)               */
/*                                                                          */
/* 3 byte receive       [TX] | [RX]                                     (*) */
/* BUS:     S     A8     ACK | D8(1)   ACK   D8(2)   ACK   D8(3)   ACK    P */
/* IRQ:       DTE   WAIT     |   WAIT          WAIT         WAIT      DTE   */
/* ICIC:      -DTE           |                              +DTE            */
/* ICCR: 0x94       0x81     |                              0xc0            */
/* ICDR:      A8             |                 D8(1)        D8(2)     D8(3) */
/*                                                                          */
/* 4 bytes or more, this part is repeated    +---------+                    */
/*                                                                          */
/*                                                                          */
/* Interrupt order and BUSY flag                                            */
/*     ___                                                 _                */
/* SDA ___\___XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXAAAAAAAAA___/                 */
/* SCL      \_/1\_/2\_/3\_/4\_/5\_/6\_/7\_/8\___/9\_____/                   */
/*                                                                          */
/*        S   D7  D6  D5  D4  D3  D2  D1  D0              P(*)              */
/*                                           ___                            */
/* WAIT IRQ ________________________________/   \___________                */
/* TACK IRQ ____________________________________/   \_______                */
/* DTE  IRQ __________________________________________/   \_                */
/* AL   IRQ XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX                */
/*         _______________________________________________                  */
/* BUSY __/                                               \_                */
/*                                                                          */
/* (*) The STOP condition is only sent by the master at the end of the last */
/* I2C message or if the I2C_M_STOP flag is set. Similarly, the BUSY bit is */
/* only cleared after the STOP condition, so, between messages we have to   */
/* poll for the DTE bit.                                                    */
/*                                                                          */


enum sh_mobile_i2c_op {
	
OP_START = 0,
	
OP_TX_FIRST,
	
OP_TX,
	
OP_TX_STOP,
	
OP_TX_STOP_DATA,
	
OP_TX_TO_RX,
	
OP_RX,
	
OP_RX_STOP,
	
OP_RX_STOP_DATA,
};


struct sh_mobile_i2c_data {
	
struct device *dev;
	
void __iomem *reg;
	
struct i2c_adapter adap;
	
unsigned long bus_speed;
	
unsigned int clks_per_count;
	
struct clk *clk;
	
u_int8_t icic;
	
u_int8_t flags;
	
u_int16_t iccl;
	
u_int16_t icch;

	
spinlock_t lock;
	
wait_queue_head_t wait;
	
struct i2c_msg *msg;
	
int pos;
	
int sr;
	
bool send_stop;
	
bool stop_after_dma;

	
struct resource *res;
	
struct dma_chan *dma_tx;
	
struct dma_chan *dma_rx;
	
struct scatterlist sg;
	
enum dma_data_direction dma_direction;
};


struct sh_mobile_dt_config {
	
int clks_per_count;
	
void (*setup)(struct sh_mobile_i2c_data *pd);
};


#define IIC_FLAG_HAS_ICIC67	(1 << 0)


#define STANDARD_MODE		100000

#define FAST_MODE		400000

/* Register offsets */

#define ICDR			0x00

#define ICCR			0x04

#define ICSR			0x08

#define ICIC			0x0c

#define ICCL			0x10

#define ICCH			0x14

#define ICSTART			0x70

/* Register bits */

#define ICCR_ICE		0x80

#define ICCR_RACK		0x40

#define ICCR_TRS		0x10

#define ICCR_BBSY		0x04

#define ICCR_SCP		0x01


#define ICSR_SCLM		0x80

#define ICSR_SDAM		0x40

#define SW_DONE			0x20

#define ICSR_BUSY		0x10

#define ICSR_AL			0x08

#define ICSR_TACK		0x04

#define ICSR_WAIT		0x02

#define ICSR_DTE		0x01


#define ICIC_ICCLB8		0x80

#define ICIC_ICCHB8		0x40

#define ICIC_TDMAE		0x20

#define ICIC_RDMAE		0x10

#define ICIC_ALE		0x08

#define ICIC_TACKE		0x04

#define ICIC_WAITE		0x02

#define ICIC_DTEE		0x01


#define ICSTART_ICSTART		0x10


static void iic_wr(struct sh_mobile_i2c_data *pd, int offs, unsigned char data) { if (offs == ICIC) data |= pd->icic; iowrite8(data, pd->reg + offs); }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm41100.00%2100.00%
Total41100.00%2100.00%


static unsigned char iic_rd(struct sh_mobile_i2c_data *pd, int offs) { return ioread8(pd->reg + offs); }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm25100.00%1100.00%
Total25100.00%1100.00%


static void iic_set_clr(struct sh_mobile_i2c_data *pd, int offs, unsigned char set, unsigned char clr) { iic_wr(pd, offs, (iic_rd(pd, offs) | set) & ~clr); }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm43100.00%1100.00%
Total43100.00%1100.00%


static u32 sh_mobile_i2c_iccl(unsigned long count_khz, u32 tLOW, u32 tf) { /* * Conditional expression: * ICCL >= COUNT_CLK * (tLOW + tf) * * SH-Mobile IIC hardware starts counting the LOW period of * the SCL signal (tLOW) as soon as it pulls the SCL line. * In order to meet the tLOW timing spec, we need to take into * account the fall time of SCL signal (tf). Default tf value * should be 0.3 us, for safety. */ return (((count_khz * (tLOW + tf)) + 5000) / 10000); }

Contributors

PersonTokensPropCommitsCommitProp
shinya kuribayashishinya kuribayashi36100.00%1100.00%
Total36100.00%1100.00%


static u32 sh_mobile_i2c_icch(unsigned long count_khz, u32 tHIGH, u32 tf) { /* * Conditional expression: * ICCH >= COUNT_CLK * (tHIGH + tf) * * SH-Mobile IIC hardware is aware of SCL transition period 'tr', * and can ignore it. SH-Mobile IIC controller starts counting * the HIGH period of the SCL signal (tHIGH) after the SCL input * voltage increases at VIH. * * Afterward it turned out calculating ICCH using only tHIGH spec * will result in violation of the tHD;STA timing spec. We need * to take into account the fall time of SDA signal (tf) at START * condition, in order to meet both tHIGH and tHD;STA specs. */ return (((count_khz * (tHIGH + tf)) + 5000) / 10000); }

Contributors

PersonTokensPropCommitsCommitProp
shinya kuribayashishinya kuribayashi36100.00%1100.00%
Total36100.00%1100.00%


static int sh_mobile_i2c_init(struct sh_mobile_i2c_data *pd) { unsigned long i2c_clk_khz; u32 tHIGH, tLOW, tf; uint16_t max_val; /* Get clock rate after clock is enabled */ clk_prepare_enable(pd->clk); i2c_clk_khz = clk_get_rate(pd->clk) / 1000; clk_disable_unprepare(pd->clk); i2c_clk_khz /= pd->clks_per_count; if (pd->bus_speed == STANDARD_MODE) { tLOW = 47; /* tLOW = 4.7 us */ tHIGH = 40; /* tHD;STA = tHIGH = 4.0 us */ tf = 3; /* tf = 0.3 us */ } else if (pd->bus_speed == FAST_MODE) { tLOW = 13; /* tLOW = 1.3 us */ tHIGH = 6; /* tHD;STA = tHIGH = 0.6 us */ tf = 3; /* tf = 0.3 us */ } else { dev_err(pd->dev, "unrecognized bus speed %lu Hz\n", pd->bus_speed); return -EINVAL; } pd->iccl = sh_mobile_i2c_iccl(i2c_clk_khz, tLOW, tf); pd->icch = sh_mobile_i2c_icch(i2c_clk_khz, tHIGH, tf); max_val = pd->flags & IIC_FLAG_HAS_ICIC67 ? 0x1ff : 0xff; if (pd->iccl > max_val || pd->icch > max_val) { dev_err(pd->dev, "timing values out of range: L/H=0x%x/0x%x\n", pd->iccl, pd->icch); return -EINVAL; } /* one more bit of ICCL in ICIC */ if (pd->iccl & 0x100) pd->icic |= ICIC_ICCLB8; else pd->icic &= ~ICIC_ICCLB8; /* one more bit of ICCH in ICIC */ if (pd->icch & 0x100) pd->icic |= ICIC_ICCHB8; else pd->icic &= ~ICIC_ICCHB8; dev_dbg(pd->dev, "timing values: L/H=0x%x/0x%x\n", pd->iccl, pd->icch); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
wolfram sangwolfram sang9736.06%327.27%
magnus dammmagnus damm8631.97%436.36%
shinya kuribayashishinya kuribayashi8531.60%327.27%
laurent pinchartlaurent pinchart10.37%19.09%
Total269100.00%11100.00%


static void activate_ch(struct sh_mobile_i2c_data *pd) { /* Wake up device and enable clock */ pm_runtime_get_sync(pd->dev); clk_prepare_enable(pd->clk); /* Enable channel and configure rx ack */ iic_set_clr(pd, ICCR, ICCR_ICE, 0); /* Mask all interrupts */ iic_wr(pd, ICIC, 0); /* Set the clock */ iic_wr(pd, ICCL, pd->iccl & 0xff); iic_wr(pd, ICCH, pd->icch & 0xff); }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm4661.33%240.00%
shinya kuribayashishinya kuribayashi2837.33%240.00%
laurent pinchartlaurent pinchart11.33%120.00%
Total75100.00%5100.00%


static void deactivate_ch(struct sh_mobile_i2c_data *pd) { /* Clear/disable interrupts */ iic_wr(pd, ICSR, 0); iic_wr(pd, ICIC, 0); /* Disable channel */ iic_set_clr(pd, ICCR, 0, ICCR_ICE); /* Disable clock and mark device as idle */ clk_disable_unprepare(pd->clk); pm_runtime_put_sync(pd->dev); }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm5698.25%375.00%
laurent pinchartlaurent pinchart11.75%125.00%
Total57100.00%4100.00%


static unsigned char i2c_op(struct sh_mobile_i2c_data *pd, enum sh_mobile_i2c_op op, unsigned char data) { unsigned char ret = 0; unsigned long flags; dev_dbg(pd->dev, "op %d, data in 0x%02x\n", op, data); spin_lock_irqsave(&pd->lock, flags); switch (op) { case OP_START: /* issue start and trigger DTE interrupt */ iic_wr(pd, ICCR, ICCR_ICE | ICCR_TRS | ICCR_BBSY); break; case OP_TX_FIRST: /* disable DTE interrupt and write data */ iic_wr(pd, ICIC, ICIC_WAITE | ICIC_ALE | ICIC_TACKE); iic_wr(pd, ICDR, data); break; case OP_TX: /* write data */ iic_wr(pd, ICDR, data); break; case OP_TX_STOP_DATA: /* write data and issue a stop afterwards */ iic_wr(pd, ICDR, data); /* fallthrough */ case OP_TX_STOP: /* issue a stop */ iic_wr(pd, ICCR, pd->send_stop ? ICCR_ICE | ICCR_TRS : ICCR_ICE | ICCR_TRS | ICCR_BBSY); break; case OP_TX_TO_RX: /* select read mode */ iic_wr(pd, ICCR, ICCR_ICE | ICCR_SCP); break; case OP_RX: /* just read data */ ret = iic_rd(pd, ICDR); break; case OP_RX_STOP: /* enable DTE interrupt, issue stop */ iic_wr(pd, ICIC, ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE); iic_wr(pd, ICCR, ICCR_ICE | ICCR_RACK); break; case OP_RX_STOP_DATA: /* enable DTE interrupt, read data, issue stop */ iic_wr(pd, ICIC, ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE); ret = iic_rd(pd, ICDR); iic_wr(pd, ICCR, ICCR_ICE | ICCR_RACK); break; } spin_unlock_irqrestore(&pd->lock, flags); dev_dbg(pd->dev, "op %d, data out 0x%02x\n", op, ret); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm25288.42%350.00%
wolfram sangwolfram sang289.82%233.33%
guennadi liakhovetskiguennadi liakhovetski51.75%116.67%
Total285100.00%6100.00%


static bool sh_mobile_i2c_is_first_byte(struct sh_mobile_i2c_data *pd) { return pd->pos == -1; }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm1789.47%266.67%
guennadi liakhovetskiguennadi liakhovetski210.53%133.33%
Total19100.00%3100.00%


static bool sh_mobile_i2c_is_last_byte(struct sh_mobile_i2c_data *pd) { return pd->pos == pd->msg->len - 1; }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm2291.67%266.67%
guennadi liakhovetskiguennadi liakhovetski28.33%133.33%
Total24100.00%3100.00%


static void sh_mobile_i2c_get_data(struct sh_mobile_i2c_data *pd, unsigned char *buf) { switch (pd->pos) { case -1: *buf = i2c_8bit_addr_from_msg(pd->msg); break; default: *buf = pd->msg->buf[pd->pos]; } }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm5194.44%266.67%
wolfram sangwolfram sang35.56%133.33%
Total54100.00%3100.00%


static int sh_mobile_i2c_isr_tx(struct sh_mobile_i2c_data *pd) { unsigned char data; if (pd->pos == pd->msg->len) { /* Send stop if we haven't yet (DMA case) */ if (pd->send_stop && pd->stop_after_dma) i2c_op(pd, OP_TX_STOP, 0); return 1; } sh_mobile_i2c_get_data(pd, &data); if (sh_mobile_i2c_is_last_byte(pd)) i2c_op(pd, OP_TX_STOP_DATA, data); else if (sh_mobile_i2c_is_first_byte(pd)) i2c_op(pd, OP_TX_FIRST, data); else i2c_op(pd, OP_TX, data); pd->pos++; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm8879.28%250.00%
wolfram sangwolfram sang2320.72%250.00%
Total111100.00%4100.00%


static int sh_mobile_i2c_isr_rx(struct sh_mobile_i2c_data *pd) { unsigned char data; int real_pos; do { if (pd->pos <= -1) { sh_mobile_i2c_get_data(pd, &data); if (sh_mobile_i2c_is_first_byte(pd)) i2c_op(pd, OP_TX_FIRST, data); else i2c_op(pd, OP_TX, data); break; } if (pd->pos == 0) { i2c_op(pd, OP_TX_TO_RX, 0); break; } real_pos = pd->pos - 2; if (pd->pos == pd->msg->len) { if (pd->stop_after_dma) { /* Simulate PIO end condition after DMA transfer */ i2c_op(pd, OP_RX_STOP, 0); pd->pos++; break; } if (real_pos < 0) { i2c_op(pd, OP_RX_STOP, 0); break; } data = i2c_op(pd, OP_RX_STOP_DATA, 0); } else data = i2c_op(pd, OP_RX, 0); if (real_pos >= 0) pd->msg->buf[real_pos] = data; } while (0); pd->pos++; return pd->pos == (pd->msg->len + 2); }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm19288.89%375.00%
wolfram sangwolfram sang2411.11%125.00%
Total216100.00%4100.00%


static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id) { struct sh_mobile_i2c_data *pd = dev_id; unsigned char sr; int wakeup = 0; sr = iic_rd(pd, ICSR); pd->sr |= sr; /* remember state */ dev_dbg(pd->dev, "i2c_isr 0x%02x 0x%02x %s %d %d!\n", sr, pd->sr, (pd->msg->flags & I2C_M_RD) ? "read" : "write", pd->pos, pd->msg->len); /* Kick off TxDMA after preface was done */ if (pd->dma_direction == DMA_TO_DEVICE && pd->pos == 0) iic_set_clr(pd, ICIC, ICIC_TDMAE, 0); else if (sr & (ICSR_AL | ICSR_TACK)) /* don't interrupt transaction - continue to issue stop */ iic_wr(pd, ICSR, sr & ~(ICSR_AL | ICSR_TACK)); else if (pd->msg->flags & I2C_M_RD) wakeup = sh_mobile_i2c_isr_rx(pd); else wakeup = sh_mobile_i2c_isr_tx(pd); /* Kick off RxDMA after preface was done */ if (pd->dma_direction == DMA_FROM_DEVICE && pd->pos == 1) iic_set_clr(pd, ICIC, ICIC_RDMAE, 0); if (sr & ICSR_WAIT) /* TODO: add delay here to support slow acks */ iic_wr(pd, ICSR, sr & ~ICSR_WAIT); if (wakeup) { pd->sr |= SW_DONE; wake_up(&pd->wait); } /* defeat write posting to avoid spurious WAIT interrupts */ iic_rd(pd, ICSR); return IRQ_HANDLED; }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm17673.33%350.00%
wolfram sangwolfram sang5623.33%233.33%
shinya kuribayashishinya kuribayashi83.33%116.67%
Total240100.00%6100.00%


static void sh_mobile_i2c_dma_unmap(struct sh_mobile_i2c_data *pd) { struct dma_chan *chan = pd->dma_direction == DMA_FROM_DEVICE ? pd->dma_rx : pd->dma_tx; dma_unmap_single(chan->device->dev, sg_dma_address(&pd->sg), pd->msg->len, pd->dma_direction); pd->dma_direction = DMA_NONE; }

Contributors

PersonTokensPropCommitsCommitProp
wolfram sangwolfram sang63100.00%1100.00%
Total63100.00%1100.00%


static void sh_mobile_i2c_cleanup_dma(struct sh_mobile_i2c_data *pd) { if (pd->dma_direction == DMA_NONE) return; else if (pd->dma_direction == DMA_FROM_DEVICE) dmaengine_terminate_all(pd->dma_rx); else if (pd->dma_direction == DMA_TO_DEVICE) dmaengine_terminate_all(pd->dma_tx); sh_mobile_i2c_dma_unmap(pd); }

Contributors

PersonTokensPropCommitsCommitProp
wolfram sangwolfram sang2747.37%240.00%
magnus dammmagnus damm2747.37%240.00%
guennadi liakhovetskiguennadi liakhovetski35.26%120.00%
Total57100.00%5100.00%


static void sh_mobile_i2c_dma_callback(void *data) { struct sh_mobile_i2c_data *pd = data; sh_mobile_i2c_dma_unmap(pd); pd->pos = pd->msg->len; pd->stop_after_dma = true; iic_set_clr(pd, ICIC, 0, ICIC_TDMAE | ICIC_RDMAE); }

Contributors

PersonTokensPropCommitsCommitProp
wolfram sangwolfram sang3568.63%360.00%
magnus dammmagnus damm1631.37%240.00%
Total51100.00%5100.00%


static struct dma_chan *sh_mobile_i2c_request_dma_chan(struct device *dev, enum dma_transfer_direction dir, dma_addr_t port_addr) { struct dma_chan *chan; struct dma_slave_config cfg; char *chan_name = dir == DMA_MEM_TO_DEV ? "tx" : "rx"; int ret; chan = dma_request_slave_channel_reason(dev, chan_name); if (IS_ERR(chan)) { ret = PTR_ERR(chan); dev_dbg(dev, "request_channel failed for %s (%d)\n", chan_name, ret); return chan; } memset(&cfg, 0, sizeof(cfg)); cfg.direction = dir; if (dir == DMA_MEM_TO_DEV) { cfg.dst_addr = port_addr; cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; } else { cfg.src_addr = port_addr; cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; } ret = dmaengine_slave_config(chan, &cfg); if (ret) { dev_dbg(dev, "slave_config failed for %s (%d)\n", chan_name, ret); dma_release_channel(chan); return ERR_PTR(ret); } dev_dbg(dev, "got DMA channel for %s\n", chan_name); return chan; }

Contributors

PersonTokensPropCommitsCommitProp
wolfram sangwolfram sang187100.00%2100.00%
Total187100.00%2100.00%


static void sh_mobile_i2c_xfer_dma(struct sh_mobile_i2c_data *pd) { bool read = pd->msg->flags & I2C_M_RD; enum dma_data_direction dir = read ? DMA_FROM_DEVICE : DMA_TO_DEVICE; struct dma_chan *chan = read ? pd->dma_rx : pd->dma_tx; struct dma_async_tx_descriptor *txdesc; dma_addr_t dma_addr; dma_cookie_t cookie; if (PTR_ERR(chan) == -EPROBE_DEFER) { if (read) chan = pd->dma_rx = sh_mobile_i2c_request_dma_chan(pd->dev, DMA_DEV_TO_MEM, pd->res->start + ICDR); else chan = pd->dma_tx = sh_mobile_i2c_request_dma_chan(pd->dev, DMA_MEM_TO_DEV, pd->res->start + ICDR); } if (IS_ERR(chan)) return; dma_addr = dma_map_single(chan->device->dev, pd->msg->buf, pd->msg->len, dir); if (dma_mapping_error(pd->dev, dma_addr)) { dev_dbg(pd->dev, "dma map failed, using PIO\n"); return; } sg_dma_len(&pd->sg) = pd->msg->len; sg_dma_address(&pd->sg) = dma_addr; pd->dma_direction = dir; txdesc = dmaengine_prep_slave_sg(chan, &pd->sg, 1, read ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!txdesc) { dev_dbg(pd->dev, "dma prep slave sg failed, using PIO\n"); sh_mobile_i2c_cleanup_dma(pd); return; } txdesc->callback = sh_mobile_i2c_dma_callback; txdesc->callback_param = pd; cookie = dmaengine_submit(txdesc); if (dma_submit_error(cookie)) { dev_dbg(pd->dev, "submitting dma failed, using PIO\n"); sh_mobile_i2c_cleanup_dma(pd); return; } dma_async_issue_pending(chan); }

Contributors

PersonTokensPropCommitsCommitProp
wolfram sangwolfram sang301100.00%4100.00%
Total301100.00%4100.00%


static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg, bool do_init) { if (usr_msg->len == 0 && (usr_msg->flags & I2C_M_RD)) { dev_err(pd->dev, "Unsupported zero length i2c read\n"); return -EOPNOTSUPP; } if (do_init) { /* Initialize channel registers */ iic_set_clr(pd, ICCR, 0, ICCR_ICE); /* Enable channel and configure rx ack */ iic_set_clr(pd, ICCR, ICCR_ICE, 0); /* Set the clock */ iic_wr(pd, ICCL, pd->iccl & 0xff); iic_wr(pd, ICCH, pd->icch & 0xff); } pd->msg = usr_msg; pd->pos = -1; pd->sr = 0; if (pd->msg->len > 8) sh_mobile_i2c_xfer_dma(pd); /* Enable all interrupts to begin with */ iic_wr(pd, ICIC, ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
wolfram sangwolfram sang15295.00%150.00%
magnus dammmagnus damm85.00%150.00%
Total160100.00%2100.00%


static int poll_dte(struct sh_mobile_i2c_data *pd) { int i; for (i = 1000; i; i--) { u_int8_t val = iic_rd(pd, ICSR); if (val & ICSR_DTE) break; if (val & ICSR_TACK) return -ENXIO; udelay(10); } return i ? 0 : -ETIMEDOUT; }

Contributors

PersonTokensPropCommitsCommitProp
guennadi liakhovetskiguennadi liakhovetski6292.54%150.00%
wolfram sangwolfram sang57.46%150.00%
Total67100.00%2100.00%


static int poll_busy(struct sh_mobile_i2c_data *pd) { int i; for (i = 1000; i; i--) { u_int8_t val = iic_rd(pd, ICSR); dev_dbg(pd->dev, "val 0x%02x pd->sr 0x%02x\n", val, pd->sr); /* the interrupt handler may wake us up before the * transfer is finished, so poll the hardware * until we're done. */ if (!(val & ICSR_BUSY)) { /* handle missing acknowledge and arbitration lost */ val |= pd->sr; if (val & ICSR_TACK) return -ENXIO; if (val & ICSR_AL) return -EAGAIN; break; } udelay(10); } return i ? 0 : -ETIMEDOUT; }

Contributors

PersonTokensPropCommitsCommitProp
guennadi liakhovetskiguennadi liakhovetski8681.90%150.00%
wolfram sangwolfram sang1918.10%150.00%
Total105100.00%2100.00%


static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num) { struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter); struct i2c_msg *msg; int err = 0; int i; long timeout; activate_ch(pd); /* Process all messages */ for (i = 0; i < num; i++) { bool do_start = pd->send_stop || !i; msg = &msgs[i]; pd->send_stop = i == num - 1 || msg->flags & I2C_M_STOP; pd->stop_after_dma = false; err = start_ch(pd, msg, do_start); if (err) break; if (do_start) i2c_op(pd, OP_START, 0); /* The interrupt handler takes care of the rest... */ timeout = wait_event_timeout(pd->wait, pd->sr & (ICSR_TACK | SW_DONE), adapter->timeout); if (!timeout) { dev_err(pd->dev, "Transfer request timed out\n"); if (pd->dma_direction != DMA_NONE) sh_mobile_i2c_cleanup_dma(pd); err = -ETIMEDOUT; break; } if (pd->send_stop) err = poll_busy(pd); else err = poll_dte(pd); if (err < 0) break; } deactivate_ch(pd); if (!err) err = num; return err; }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm15464.44%222.22%
guennadi liakhovetskiguennadi liakhovetski5824.27%333.33%
wolfram sangwolfram sang2711.30%444.44%
Total239100.00%9100.00%


static u32 sh_mobile_i2c_func(struct i2c_adapter *adapter) { return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING; }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm1688.89%150.00%
guennadi liakhovetskiguennadi liakhovetski211.11%150.00%
Total18100.00%2100.00%

static struct i2c_algorithm sh_mobile_i2c_algorithm = { .functionality = sh_mobile_i2c_func, .master_xfer = sh_mobile_i2c_xfer, }; /* * r8a7740 chip has lasting errata on I2C I/O pad reset. * this is work-around for it. */
static void sh_mobile_i2c_r8a7740_workaround(struct sh_mobile_i2c_data *pd) { iic_set_clr(pd, ICCR, ICCR_ICE, 0); iic_rd(pd, ICCR); /* dummy read */ iic_set_clr(pd, ICSTART, ICSTART_ICSTART, 0); iic_rd(pd, ICSTART); /* dummy read */ udelay(10); iic_wr(pd, ICCR, ICCR_SCP); iic_wr(pd, ICSTART, 0); udelay(10); iic_wr(pd, ICCR, ICCR_TRS); udelay(10); iic_wr(pd, ICCR, 0); udelay(10); iic_wr(pd, ICCR, ICCR_TRS); udelay(10); }

Contributors

PersonTokensPropCommitsCommitProp
wolfram sangwolfram sang119100.00%1100.00%
Total119100.00%1100.00%

static const struct sh_mobile_dt_config default_dt_config = { .clks_per_count = 1, }; static const struct sh_mobile_dt_config fast_clock_dt_config = { .clks_per_count = 2, }; static const struct sh_mobile_dt_config r8a7740_dt_config = { .clks_per_count = 1, .setup = sh_mobile_i2c_r8a7740_workaround, }; static const struct of_device_id sh_mobile_i2c_dt_ids[] = { { .compatible = "renesas,rmobile-iic", .data = &default_dt_config }, { .compatible = "renesas,iic-r8a73a4", .data = &fast_clock_dt_config }, { .compatible = "renesas,iic-r8a7740", .data = &r8a7740_dt_config }, { .compatible = "renesas,iic-r8a7790", .data = &fast_clock_dt_config }, { .compatible = "renesas,iic-r8a7791", .data = &fast_clock_dt_config }, { .compatible = "renesas,iic-r8a7792", .data = &fast_clock_dt_config }, { .compatible = "renesas,iic-r8a7793", .data = &fast_clock_dt_config }, { .compatible = "renesas,iic-r8a7794", .data = &fast_clock_dt_config }, { .compatible = "renesas,iic-r8a7795", .data = &fast_clock_dt_config }, { .compatible = "renesas,iic-sh73a0", .data = &fast_clock_dt_config }, {}, }; MODULE_DEVICE_TABLE(of, sh_mobile_i2c_dt_ids);
static void sh_mobile_i2c_release_dma(struct sh_mobile_i2c_data *pd) { if (!IS_ERR(pd->dma_tx)) { dma_release_channel(pd->dma_tx); pd->dma_tx = ERR_PTR(-EPROBE_DEFER); } if (!IS_ERR(pd->dma_rx)) { dma_release_channel(pd->dma_rx); pd->dma_rx = ERR_PTR(-EPROBE_DEFER); } }

Contributors

PersonTokensPropCommitsCommitProp
wolfram sangwolfram sang6797.10%583.33%
geert uytterhoevengeert uytterhoeven22.90%116.67%
Total69100.00%6100.00%


static int sh_mobile_i2c_hook_irqs(struct platform_device *dev, struct sh_mobile_i2c_data *pd) { struct resource *res; resource_size_t n; int k = 0, ret; while ((res = platform_get_resource(dev, IORESOURCE_IRQ, k))) { for (n = res->start; n <= res->end; n++) { ret = devm_request_irq(&dev->dev, n, sh_mobile_i2c_isr, 0, dev_name(&dev->dev), pd); if (ret) { dev_err(&dev->dev, "cannot request IRQ %pa\n", &n); return ret; } } k++; } return k > 0 ? 0 : -ENOENT; }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm8969.53%233.33%
wolfram sangwolfram sang3426.56%233.33%
jean delvarejean delvare43.12%116.67%
yong zhangyong zhang10.78%116.67%
Total128100.00%6100.00%


static int sh_mobile_i2c_probe(struct platform_device *dev) { struct i2c_sh_mobile_platform_data *pdata = dev_get_platdata(&dev->dev); struct sh_mobile_i2c_data *pd; struct i2c_adapter *adap; struct resource *res; int ret; u32 bus_speed; pd = devm_kzalloc(&dev->dev, sizeof(struct sh_mobile_i2c_data), GFP_KERNEL); if (!pd) return -ENOMEM; pd->clk = devm_clk_get(&dev->dev, NULL); if (IS_ERR(pd->clk)) { dev_err(&dev->dev, "cannot get clock\n"); return PTR_ERR(pd->clk); } ret = sh_mobile_i2c_hook_irqs(dev, pd); if (ret) return ret; pd->dev = &dev->dev; platform_set_drvdata(dev, pd); res = platform_get_resource(dev, IORESOURCE_MEM, 0); pd->res = res; pd->reg = devm_ioremap_resource(&dev->dev, res); if (IS_ERR(pd->reg)) return PTR_ERR(pd->reg); /* Use platform data bus speed or STANDARD_MODE */ ret = of_property_read_u32(dev->dev.of_node, "clock-frequency", &bus_speed); pd->bus_speed = ret ? STANDARD_MODE : bus_speed; pd->clks_per_count = 1; if (dev->dev.of_node) { const struct of_device_id *match; match = of_match_device(sh_mobile_i2c_dt_ids, &dev->dev); if (match) { const struct sh_mobile_dt_config *config; config = match->data; pd->clks_per_count = config->clks_per_count; if (config->setup) config->setup(pd); } } else { if (pdata && pdata->bus_speed) pd->bus_speed = pdata->bus_speed; if (pdata && pdata->clks_per_count) pd->clks_per_count = pdata->clks_per_count; } /* The IIC blocks on SH-Mobile ARM processors * come with two new bits in ICIC. */ if (resource_size(res) > 0x17) pd->flags |= IIC_FLAG_HAS_ICIC67; ret = sh_mobile_i2c_init(pd); if (ret) return ret; /* Init DMA */ sg_init_table(&pd->sg, 1); pd->dma_direction = DMA_NONE; pd->dma_rx = pd->dma_tx = ERR_PTR(-EPROBE_DEFER); /* Enable Runtime PM for this device. * * Also tell the Runtime PM core to ignore children * for this device since it is valid for us to suspend * this I2C master driver even though the slave devices * on the I2C bus may not be suspended. * * The state of the I2C hardware bus is unaffected by * the Runtime PM state. */ pm_suspend_ignore_children(&dev->dev, true); pm_runtime_enable(&dev->dev); /* setup the private data */ adap = &pd->adap; i2c_set_adapdata(adap, pd); adap->owner = THIS_MODULE; adap->algo = &sh_mobile_i2c_algorithm; adap->dev.parent = &dev->dev; adap->retries = 5; adap->nr = dev->id; adap->dev.of_node = dev->dev.of_node; strlcpy(adap->name, dev->name, sizeof(adap->name)); spin_lock_init(&pd->lock); init_waitqueue_head(&pd->wait); ret = i2c_add_numbered_adapter(adap); if (ret < 0) { sh_mobile_i2c_release_dma(pd); dev_err(&dev->dev, "cannot add numbered adapter\n"); return ret; } dev_info(&dev->dev, "I2C adapter %d, bus speed %lu Hz\n", adap->nr, pd->bus_speed); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm35062.17%733.33%
wolfram sangwolfram sang18633.04%1047.62%
shinya kuribayashishinya kuribayashi234.09%314.29%
jingoo hanjingoo han40.71%14.76%
Total563100.00%21100.00%


static int sh_mobile_i2c_remove(struct platform_device *dev) { struct sh_mobile_i2c_data *pd = platform_get_drvdata(dev); i2c_del_adapter(&pd->adap); sh_mobile_i2c_release_dma(pd); pm_runtime_disable(&dev->dev); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm4088.89%266.67%
wolfram sangwolfram sang511.11%133.33%
Total45100.00%3100.00%


static int sh_mobile_i2c_runtime_nop(struct device *dev) { /* Runtime PM callback shared between ->runtime_suspend() * and ->runtime_resume(). Simply returns success. * * This driver re-initializes all registers after * pm_runtime_get_sync() anyway so there is no need * to save and restore registers here. */ return 0; }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm15100.00%1100.00%
Total15100.00%1100.00%

static const struct dev_pm_ops sh_mobile_i2c_dev_pm_ops = { .runtime_suspend = sh_mobile_i2c_runtime_nop, .runtime_resume = sh_mobile_i2c_runtime_nop, }; static struct platform_driver sh_mobile_i2c_driver = { .driver = { .name = "i2c-sh_mobile", .pm = &sh_mobile_i2c_dev_pm_ops, .of_match_table = sh_mobile_i2c_dt_ids, }, .probe = sh_mobile_i2c_probe, .remove = sh_mobile_i2c_remove, };
static int __init sh_mobile_i2c_adap_init(void) { return platform_driver_register(&sh_mobile_i2c_driver); }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm16100.00%1100.00%
Total16100.00%1100.00%

subsys_initcall(sh_mobile_i2c_adap_init);
static void __exit sh_mobile_i2c_adap_exit(void) { platform_driver_unregister(&sh_mobile_i2c_driver); }

Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm15100.00%1100.00%
Total15100.00%1100.00%

module_exit(sh_mobile_i2c_adap_exit); MODULE_DESCRIPTION("SuperH Mobile I2C Bus Controller driver"); MODULE_AUTHOR("Magnus Damm and Wolfram Sang"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:i2c-sh_mobile");

Overall Contributors

PersonTokensPropCommitsCommitProp
magnus dammmagnus damm220149.67%1122.00%
wolfram sangwolfram sang173039.04%2346.00%
guennadi liakhovetskiguennadi liakhovetski2405.42%510.00%
shinya kuribayashishinya kuribayashi2295.17%48.00%
geert uytterhoevengeert uytterhoeven160.36%12.00%
jean delvarejean delvare40.09%12.00%
jingoo hanjingoo han40.09%12.00%
laurent pinchartlaurent pinchart30.07%12.00%
tejun heotejun heo20.05%12.00%
yong zhangyong zhang10.02%12.00%
alexey dobriyanalexey dobriyan10.02%12.00%
Total4431100.00%50100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
{% endraw %}