- 根目录:
- drivers
- spi
- spi-sh-msiof.c
/*
* SuperH MSIOF SPI Master Interface
*
* Copyright (c) 2009 Magnus Damm
* Copyright (C) 2014 Glider bvba
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/bitmap.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/sh_dma.h>
#include <linux/spi/sh_msiof.h>
#include <linux/spi/spi.h>
#include <asm/unaligned.h>
struct sh_msiof_chipdata {
u16 tx_fifo_size;
u16 rx_fifo_size;
u16 master_flags;
};
struct sh_msiof_spi_priv {
struct spi_master *master;
void __iomem *mapbase;
struct clk *clk;
struct platform_device *pdev;
const struct sh_msiof_chipdata *chipdata;
struct sh_msiof_spi_info *info;
struct completion done;
unsigned int tx_fifo_size;
unsigned int rx_fifo_size;
void *tx_dma_page;
void *rx_dma_page;
dma_addr_t tx_dma_addr;
dma_addr_t rx_dma_addr;
};
#define TMDR1 0x00 /* Transmit Mode Register 1 */
#define TMDR2 0x04 /* Transmit Mode Register 2 */
#define TMDR3 0x08 /* Transmit Mode Register 3 */
#define RMDR1 0x10 /* Receive Mode Register 1 */
#define RMDR2 0x14 /* Receive Mode Register 2 */
#define RMDR3 0x18 /* Receive Mode Register 3 */
#define TSCR 0x20 /* Transmit Clock Select Register */
#define RSCR 0x22 /* Receive Clock Select Register (SH, A1, APE6) */
#define CTR 0x28 /* Control Register */
#define FCTR 0x30 /* FIFO Control Register */
#define STR 0x40 /* Status Register */
#define IER 0x44 /* Interrupt Enable Register */
#define TDR1 0x48 /* Transmit Control Data Register 1 (SH, A1) */
#define TDR2 0x4c /* Transmit Control Data Register 2 (SH, A1) */
#define TFDR 0x50 /* Transmit FIFO Data Register */
#define RDR1 0x58 /* Receive Control Data Register 1 (SH, A1) */
#define RDR2 0x5c /* Receive Control Data Register 2 (SH, A1) */
#define RFDR 0x60 /* Receive FIFO Data Register */
/* TMDR1 and RMDR1 */
#define MDR1_TRMD 0x80000000 /* Transfer Mode (1 = Master mode) */
#define MDR1_SYNCMD_MASK 0x30000000 /* SYNC Mode */
#define MDR1_SYNCMD_SPI 0x20000000 /* Level mode/SPI */
#define MDR1_SYNCMD_LR 0x30000000 /* L/R mode */
#define MDR1_SYNCAC_SHIFT 25 /* Sync Polarity (1 = Active-low) */
#define MDR1_BITLSB_SHIFT 24 /* MSB/LSB First (1 = LSB first) */
#define MDR1_DTDL_SHIFT 20 /* Data Pin Bit Delay for MSIOF_SYNC */
#define MDR1_SYNCDL_SHIFT 16 /* Frame Sync Signal Timing Delay */
#define MDR1_FLD_MASK 0x0000000c /* Frame Sync Signal Interval (0-3) */
#define MDR1_FLD_SHIFT 2
#define MDR1_XXSTP 0x00000001 /* Transmission/Reception Stop on FIFO */
/* TMDR1 */
#define TMDR1_PCON 0x40000000 /* Transfer Signal Connection */
/* TMDR2 and RMDR2 */
#define MDR2_BITLEN1(i) (((i) - 1) << 24) /* Data Size (8-32 bits) */
#define MDR2_WDLEN1(i) (((i) - 1) << 16) /* Word Count (1-64/256 (SH, A1))) */
#define MDR2_GRPMASK1 0x00000001 /* Group Output Mask 1 (SH, A1) */
/* TSCR and RSCR */
#define SCR_BRPS_MASK 0x1f00 /* Prescaler Setting (1-32) */
#define SCR_BRPS(i) (((i) - 1) << 8)
#define SCR_BRDV_MASK 0x0007 /* Baud Rate Generator's Division Ratio */
#define SCR_BRDV_DIV_2 0x0000
#define SCR_BRDV_DIV_4 0x0001
#define SCR_BRDV_DIV_8 0x0002
#define SCR_BRDV_DIV_16 0x0003
#define SCR_BRDV_DIV_32 0x0004
#define SCR_BRDV_DIV_1 0x0007
/* CTR */
#define CTR_TSCKIZ_MASK 0xc0000000 /* Transmit Clock I/O Polarity Select */
#define CTR_TSCKIZ_SCK 0x80000000 /* Disable SCK when TX disabled */
#define CTR_TSCKIZ_POL_SHIFT 30 /* Transmit Clock Polarity */
#define CTR_RSCKIZ_MASK 0x30000000 /* Receive Clock Polarity Select */
#define CTR_RSCKIZ_SCK 0x20000000 /* Must match CTR_TSCKIZ_SCK */
#define CTR_RSCKIZ_POL_SHIFT 28 /* Receive Clock Polarity */
#define CTR_TEDG_SHIFT 27 /* Transmit Timing (1 = falling edge) */
#define CTR_REDG_SHIFT 26 /* Receive Timing (1 = falling edge) */
#define CTR_TXDIZ_MASK 0x00c00000 /* Pin Output When TX is Disabled */
#define CTR_TXDIZ_LOW 0x00000000 /* 0 */
#define CTR_TXDIZ_HIGH 0x00400000 /* 1 */
#define CTR_TXDIZ_HIZ 0x00800000 /* High-impedance */
#define CTR_TSCKE 0x00008000 /* Transmit Serial Clock Output Enable */
#define CTR_TFSE 0x00004000 /* Transmit Frame Sync Signal Output Enable */
#define CTR_TXE 0x00000200 /* Transmit Enable */
#define CTR_RXE 0x00000100 /* Receive Enable */
/* FCTR */
#define FCTR_TFWM_MASK 0xe0000000 /* Transmit FIFO Watermark */
#define FCTR_TFWM_64 0x00000000 /* Transfer Request when 64 empty stages */
#define FCTR_TFWM_32 0x20000000 /* Transfer Request when 32 empty stages */
#define FCTR_TFWM_24 0x40000000 /* Transfer Request when 24 empty stages */
#define FCTR_TFWM_16 0x60000000 /* Transfer Request when 16 empty stages */
#define FCTR_TFWM_12 0x80000000 /* Transfer Request when 12 empty stages */
#define FCTR_TFWM_8 0xa0000000 /* Transfer Request when 8 empty stages */
#define FCTR_TFWM_4 0xc0000000 /* Transfer Request when 4 empty stages */
#define FCTR_TFWM_1 0xe0000000 /* Transfer Request when 1 empty stage */
#define FCTR_TFUA_MASK 0x07f00000 /* Transmit FIFO Usable Area */
#define FCTR_TFUA_SHIFT 20
#define FCTR_TFUA(i) ((i) << FCTR_TFUA_SHIFT)
#define FCTR_RFWM_MASK 0x0000e000 /* Receive FIFO Watermark */
#define FCTR_RFWM_1 0x00000000 /* Transfer Request when 1 valid stages */
#define FCTR_RFWM_4 0x00002000 /* Transfer Request when 4 valid stages */
#define FCTR_RFWM_8 0x00004000 /* Transfer Request when 8 valid stages */
#define FCTR_RFWM_16 0x00006000 /* Transfer Request when 16 valid stages */
#define FCTR_RFWM_32 0x00008000 /* Transfer Request when 32 valid stages */
#define FCTR_RFWM_64 0x0000a000 /* Transfer Request when 64 valid stages */
#define FCTR_RFWM_128 0x0000c000 /* Transfer Request when 128 valid stages */
#define FCTR_RFWM_256 0x0000e000 /* Transfer Request when 256 valid stages */
#define FCTR_RFUA_MASK 0x00001ff0 /* Receive FIFO Usable Area (0x40 = full) */
#define FCTR_RFUA_SHIFT 4
#define FCTR_RFUA(i) ((i) << FCTR_RFUA_SHIFT)
/* STR */
#define STR_TFEMP 0x20000000 /* Transmit FIFO Empty */
#define STR_TDREQ 0x10000000 /* Transmit Data Transfer Request */
#define STR_TEOF 0x00800000 /* Frame Transmission End */
#define STR_TFSERR 0x00200000 /* Transmit Frame Synchronization Error */
#define STR_TFOVF 0x00100000 /* Transmit FIFO Overflow */
#define STR_TFUDF 0x00080000 /* Transmit FIFO Underflow */
#define STR_RFFUL 0x00002000 /* Receive FIFO Full */
#define STR_RDREQ 0x00001000 /* Receive Data Transfer Request */
#define STR_REOF 0x00000080 /* Frame Reception End */
#define STR_RFSERR 0x00000020 /* Receive Frame Synchronization Error */
#define STR_RFUDF 0x00000010 /* Receive FIFO Underflow */
#define STR_RFOVF 0x00000008 /* Receive FIFO Overflow */
/* IER */
#define IER_TDMAE 0x80000000 /* Transmit Data DMA Transfer Req. Enable */
#define IER_TFEMPE 0x20000000 /* Transmit FIFO Empty Enable */
#define IER_TDREQE 0x10000000 /* Transmit Data Transfer Request Enable */
#define IER_TEOFE 0x00800000 /* Frame Transmission End Enable */
#define IER_TFSERRE 0x00200000 /* Transmit Frame Sync Error Enable */
#define IER_TFOVFE 0x00100000 /* Transmit FIFO Overflow Enable */
#define IER_TFUDFE 0x00080000 /* Transmit FIFO Underflow Enable */
#define IER_RDMAE 0x00008000 /* Receive Data DMA Transfer Req. Enable */
#define IER_RFFULE 0x00002000 /* Receive FIFO Full Enable */
#define IER_RDREQE 0x00001000 /* Receive Data Transfer Request Enable */
#define IER_REOFE 0x00000080 /* Frame Reception End Enable */
#define IER_RFSERRE 0x00000020 /* Receive Frame Sync Error Enable */
#define IER_RFUDFE 0x00000010 /* Receive FIFO Underflow Enable */
#define IER_RFOVFE 0x00000008 /* Receive FIFO Overflow Enable */
static u32 sh_msiof_read(struct sh_msiof_spi_priv *p, int reg_offs)
{
switch (reg_offs) {
case TSCR:
case RSCR:
return ioread16(p->mapbase + reg_offs);
default:
return ioread32(p->mapbase + reg_offs);
}
}
static void sh_msiof_write(struct sh_msiof_spi_priv *p, int reg_offs,
u32 value)
{
switch (reg_offs) {
case TSCR:
case RSCR:
iowrite16(value, p->mapbase + reg_offs);
break;
default:
iowrite32(value, p->mapbase + reg_offs);
break;
}
}
static int sh_msiof_modify_ctr_wait(struct sh_msiof_spi_priv *p,
u32 clr, u32 set)
{
u32 mask = clr | set;
u32 data;
int k;
data = sh_msiof_read(p, CTR);
data &= ~clr;
data |= set;
sh_msiof_write(p, CTR, data);
for (k = 100; k > 0; k--) {
if ((sh_msiof_read(p, CTR) & mask) == set)
break;
udelay(10);
}
return k > 0 ? 0 : -ETIMEDOUT;
}
static irqreturn_t sh_msiof_spi_irq(int irq, void *data)
{
struct sh_msiof_spi_priv *p = data;
/* just disable the interrupt and wake up */
sh_msiof_write(p, IER, 0);
complete(&p->done);
return IRQ_HANDLED;
}
static struct {
unsigned short div;
unsigned short brdv;
} const sh_msiof_spi_div_table[] = {
{ 1, SCR_BRDV_DIV_1 },
{ 2, SCR_BRDV_DIV_2 },
{ 4, SCR_BRDV_DIV_4 },
{ 8, SCR_BRDV_DIV_8 },
{ 16, SCR_BRDV_DIV_16 },
{ 32, SCR_BRDV_DIV_32 },
};
static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p,
unsigned long parent_rate, u32 spi_hz)
{
unsigned long div = 1024;
u32 brps, scr;
size_t k;
if (!WARN_ON(!spi_hz || !parent_rate))
div = DIV_ROUND_UP(parent_rate, spi_hz);
for (k = 0; k < ARRAY_SIZE(sh_msiof_spi_div_table); k++) {
brps = DIV_ROUND_UP(div, sh_msiof_spi_div_table[k].div);
if (brps <= 32) /* max of brdv is 32 */
break;
}
k = min_t(int, k, ARRAY_SIZE(sh_msiof_spi_div_table) - 1);
scr = sh_msiof_spi_div_table[k].brdv | SCR_BRPS(brps);
sh_msiof_write(p, TSCR, scr);
if (!(p->chipdata->master_flags & SPI_MASTER_MUST_TX))
sh_msiof_write(p, RSCR, scr);
}
static u32 sh_msiof_get_delay_bit(u32 dtdl_or_syncdl)
{
/*
* DTDL/SYNCDL bit : p->info->dtdl or p->info->syncdl
* b'000 : 0
* b'001 : 100
* b'010 : 200
* b'011 (SYNCDL only) : 300
* b'101 : 50
* b'110 : 150
*/
if (dtdl_or_syncdl % 100)
return dtdl_or_syncdl / 100 + 5;
else
return dtdl_or_syncdl / 100;
}
static u32 sh_msiof_spi_get_dtdl_and_syncdl(struct sh_msiof_spi_priv *p)
{
u32 val;
if (!p->info)
return 0;
/* check if DTDL and SYNCDL is allowed value */
if (p->info->dtdl > 200 || p->info->syncdl > 300) {
dev_warn(&p->pdev->dev, "DTDL or SYNCDL is too large\n");
return 0;
}
/* check if the sum of DTDL and SYNCDL becomes an integer value */
if ((p->info->dtdl + p->info->syncdl) % 100) {
dev_warn(&p->pdev->dev, "the sum of DTDL/SYNCDL is not good\n");
return 0;
}
val = sh_msiof_get_delay_bit(p->info->dtdl) << MDR1_DTDL_SHIFT;
val |= sh_msiof_get_delay_bit(p->info->syncdl) << MDR1_SYNCDL_SHIFT;
return val;
}
static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
u32 cpol, u32 cpha,
u32 tx_hi_z, u32 lsb_first, u32 cs_high)
{
u32 tmp;
int edge;
/*
* CPOL CPHA TSCKIZ RSCKIZ TEDG REDG
* 0 0 10 10 1 1
* 0 1 10 10 0 0
* 1 0 11 11 0 0
* 1 1 11 11 1 1
*/
tmp = MDR1_SYNCMD_SPI | 1 << MDR1_FLD_SHIFT | MDR1_XXSTP;
tmp |= !cs_high << MDR1_SYNCAC_SHIFT;
tmp |= lsb_first << MDR1_BITLSB_SHIFT;
tmp |= sh_msiof_spi_get_dtdl_and_syncdl(p);
sh_msiof_write(p, TMDR1, tmp | MDR1_TRMD | TMDR1_PCON);
if (p->chipdata->master_flags & SPI_MASTER_MUST_TX) {
/* These bits are reserved if RX needs TX */
tmp &= ~0x0000ffff;
}
sh_msiof_write(p, RMDR1, tmp);
tmp = 0;
tmp |= CTR_TSCKIZ_SCK | cpol << CTR_TSCKIZ_POL_SHIFT;
tmp |= CTR_RSCKIZ_SCK | cpol << CTR_RSCKIZ_POL_SHIFT;
edge = cpol ^ !cpha;
tmp |= edge << CTR_TEDG_SHIFT;
tmp |= edge << CTR_REDG_SHIFT;
tmp |= tx_hi_z ? CTR_TXDIZ_HIZ : CTR_TXDIZ_LOW;
sh_msiof_write(p, CTR, tmp);
}
static void sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv *p,
const void *tx_buf, void *rx_buf,
u32 bits, u32 words)
{
u32 dr2 = MDR2_BITLEN1(bits) | MDR2_WDLEN1(words);
if (tx_buf || (p->chipdata->master_flags & SPI_MASTER_MUST_TX))
sh_msiof_write(p, TMDR2, dr2);
else
sh_msiof_write(p, TMDR2, dr2 | MDR2_GRPMASK1);
if (rx_buf)
sh_msiof_write(p, RMDR2, dr2);
}
static void sh_msiof_reset_str(struct sh_msiof_spi_priv *p)
{
sh_msiof_write(p, STR, sh_msiof_read(p, STR));
}
static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv *p,
const void *tx_buf, int words, int fs)
{
const u8 *buf_8 = tx_buf;
int k;
for (k = 0; k < words; k++)
sh_msiof_write(p, TFDR, buf_8[k] << fs);
}
static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv *p,
const void *tx_buf, int words, int fs)
{
const u16 *buf_16 = tx_buf;
int k;
for (k = 0; k < words; k++)
sh_msiof_write(p, TFDR, buf_16[k] << fs);
}
static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv *p,
const void *tx_buf, int words, int fs)
{
const u16 *buf_16 = tx_buf;
int k;
for (k = 0; k < words; k++)
sh_msiof_write(p, TFDR, get_unaligned(&buf_16[k]) << fs);
}
static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv *p,
const void *tx_buf, int words, int fs)
{
const u32 *buf_32 = tx_buf;
int k;
for (k = 0; k < words; k++)
sh_msiof_write(p, TFDR, buf_32[k] << fs);
}
static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv *p,
const void *tx_buf, int words, int fs)
{
const u32 *buf_32 = tx_buf;
int k;
for (k = 0; k < words; k++)
sh_msiof_write(p, TFDR, get_unaligned(&buf_32[k]) << fs);
}
static void sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv *p,
const void *tx_buf, int words, int fs)
{
const u32 *buf_32 = tx_buf;
int k;
for (k = 0; k < words; k++)
sh_msiof_write(p, TFDR, swab32(buf_32[k] << fs));
}
static void sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv *p,
const void *tx_buf, int words, int fs)
{
const u32 *buf_32 = tx_buf;
int k;
for (k = 0; k < words; k++)
sh_msiof_write(p, TFDR, swab32(get_unaligned(&buf_32[k]) << fs));
}
static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv *p,
void *rx_buf, int words, int fs)
{
u8 *buf_8 = rx_buf;
int k;
for (k = 0; k < words; k++)
buf_8[k] = sh_msiof_read(p, RFDR) >> fs;
}
static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv *p,
void *rx_buf, int words, int fs)
{
u16 *buf_16 = rx_buf;
int k;
for (k = 0; k < words; k++)
buf_16[k] = sh_msiof_read(p, RFDR) >> fs;
}
static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv *p,
void *rx_buf, int words, int fs)
{
u16 *buf_16 = rx_buf;
int k;
for (k = 0; k < words; k++)
put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_16[k]);
}
static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv *p,
void *rx_buf, int words, int fs)
{
u32 *buf_32 = rx_buf;
int k;
for (k = 0; k < words; k++)
buf_32[k] = sh_msiof_read(p, RFDR) >> fs;
}
static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv *p,
void *rx_buf, int words, int fs)
{
u32 *buf_32 = rx_buf;
int k;
for (k = 0; k < words; k++)
put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_32[k]);
}
static void sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv *p,
void *rx_buf, int words, int fs)
{
u32 *buf_32 = rx_buf;
int k;
for (k = 0; k < words; k++)
buf_32[k] = swab32(sh_msiof_read(p, RFDR) >> fs);
}
static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv *p,
void *rx_buf, int words, int fs)
{
u32 *buf_32 = rx_buf;
int k;
for (k = 0; k < words; k++)
put_unaligned(swab32(sh_msiof_read(p, RFDR) >> fs), &buf_32[k]);
}
static int sh_msiof_spi_setup(struct spi_device *spi)
{
struct device_node *np = spi->master->dev.of_node;
struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);
pm_runtime_get_sync(&p->pdev->dev);
if (!np) {
/*
* Use spi->controller_data for CS (same strategy as spi_gpio),
* if any. otherwise let HW control CS
*/
spi->cs_gpio = (uintptr_t)spi->controller_data;
}
/* Configure pins before deasserting CS */
sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
!!(spi->mode & SPI_CPHA),
!!(spi->mode & SPI_3WIRE),
!!(spi->mode & SPI_LSB_FIRST),
!!(spi->mode & SPI_CS_HIGH));
if (spi->cs_gpio >= 0)
gpio_set_value(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
pm_runtime_put(&p->pdev->dev);
return 0;
}
static int sh_msiof_prepare_message(struct spi_master *master,
struct spi_message *msg)
{
struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
const struct spi_device *spi = msg->spi;
/* Configure pins before asserting CS */
sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
!!(spi->mode & SPI_CPHA),
!!(spi->mode & SPI_3WIRE),
!!(spi->mode & SPI_LSB_FIRST),
!!(spi->mode & SPI_CS_HIGH));
return 0;
}
static int sh_msiof_spi_start(struct sh_msiof_spi_priv *p, void *rx_buf)
{
int ret;
/* setup clock and rx/tx signals */
ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE);
if (rx_buf && !ret)
ret = sh_msiof_modify_ctr_wait(p, 0, CTR_RXE);
if (!ret)
ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TXE);
/* start by setting frame bit */
if (!ret)
ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE);
return ret;
}
static int sh_msiof_spi_stop(struct sh_msiof_spi_priv *p, void *rx_buf)
{
int ret;
/* shut down frame, rx/tx and clock signals */
ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0);
if (!ret)
ret = sh_msiof_modify_ctr_wait(p, CTR_TXE, 0);
if (rx_buf && !ret)
ret = sh_msiof_modify_ctr_wait(p, CTR_RXE, 0);
if (!ret)
ret = sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0);
return ret;
}
static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv *p,
void (*tx_fifo)(struct sh_msiof_spi_priv *,
const void *, int, int),
void (*rx_fifo)(struct sh_msiof_spi_priv *,
void *, int, int),
const void *tx_buf, void *rx_buf,
int words, int bits)
{
int fifo_shift;
int ret;
/* limit maximum word transfer to rx/tx fifo size */
if (tx_buf)
words = min_t(int, words, p->tx_fifo_size);
if (rx_buf)
words = min_t(int, words, p->rx_fifo_size);
/* the fifo contents need shifting */
fifo_shift = 32 - bits;
/* default FIFO watermarks for PIO */
sh_msiof_write(p, FCTR, 0);
/* setup msiof transfer mode registers */
sh_msiof_spi_set_mode_regs(p, tx_buf, rx_buf, bits, words);
sh_msiof_write(p, IER, IER_TEOFE | IER_REOFE);
/* write tx fifo */
if (tx_buf)
tx_fifo(p, tx_buf, words, fifo_shift);
reinit_completion(&p->done);
ret = sh_msiof_spi_start(p, rx_buf);
if (ret) {
dev_err(&p->pdev->dev, "failed to start hardware\n");
goto stop_ier;
}
/* wait for tx fifo to be emptied / rx fifo to be filled */
if (!wait_for_completion_timeout(&p->done, HZ)) {
dev_err(&p->pdev->dev, "PIO timeout\n");
ret = -ETIMEDOUT;
goto stop_reset;
}
/* read rx fifo */
if (rx_buf)
rx_fifo(p, rx_buf, words, fifo_shift);
/* clear status bits */
sh_msiof_reset_str(p);
ret = sh_msiof_spi_stop(p, rx_buf);
if (ret) {
dev_err(&p->pdev->dev, "failed to shut down hardware\n");
return ret;
}
return words;
stop_reset:
sh_msiof_reset_str(p);
sh_msiof_spi_stop(p, rx_buf);
stop_ier:
sh_msiof_write(p, IER, 0);
return ret;
}
static void sh_msiof_dma_complete(void *arg)
{
struct sh_msiof_spi_priv *p = arg;
sh_msiof_write(p, IER, 0);
complete(&p->done);
}
static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx,
void *rx, unsigned int len)
{
u32 ier_bits = 0;
struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
dma_cookie_t cookie;
int ret;
/* First prepare and submit the DMA request(s), as this may fail */
if (rx) {
ier_bits |= IER_RDREQE | IER_RDMAE;
desc_rx = dmaengine_prep_slave_single(p->master->dma_rx,
p->rx_dma_addr, len, DMA_FROM_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_rx)
return -EAGAIN;
desc_rx->callback = sh_msiof_dma_complete;
desc_rx->callback_param = p;
cookie = dmaengine_submit(desc_rx);
if (dma_submit_error(cookie))
return cookie;
}
if (tx) {
ier_bits |= IER_TDREQE | IER_TDMAE;
dma_sync_single_for_device(p->master->dma_tx->device->dev,
p->tx_dma_addr, len, DMA_TO_DEVICE);
desc_tx = dmaengine_prep_slave_single(p->master->dma_tx,
p->tx_dma_addr, len, DMA_TO_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_tx) {
ret = -EAGAIN;
goto no_dma_tx;
}
if (rx) {
/* No callback */
desc_tx->callback = NULL;
} else {
desc_tx->callback = sh_msiof_dma_complete;
desc_tx->callback_param = p;
}
cookie = dmaengine_submit(desc_tx);
if (dma_submit_error(cookie)) {
ret = cookie;
goto no_dma_tx;
}
}
/* 1 stage FIFO watermarks for DMA */
sh_msiof_write(p, FCTR, FCTR_TFWM_1 | FCTR_RFWM_1);
/* setup msiof transfer mode registers (32-bit words) */
sh_msiof_spi_set_mode_regs(p, tx, rx, 32, len / 4);
sh_msiof_write(p, IER, ier_bits);
reinit_completion(&p->done);
/* Now start DMA */
if (rx)
dma_async_issue_pending(p->master->dma_rx);
if (tx)
dma_async_issue_pending(p->master->dma_tx);
ret = sh_msiof_spi_start(p, rx);
if (ret) {
dev_err(&p->pdev->dev, "failed to start hardware\n");
goto stop_dma;
}
/* wait for tx fifo to be emptied / rx fifo to be filled */
if (!wait_for_completion_timeout(&p->done, HZ)) {
dev_err(&p->pdev->dev, "DMA timeout\n");
ret = -ETIMEDOUT;
goto stop_reset;
}
/* clear status bits */
sh_msiof_reset_str(p);
ret = sh_msiof_spi_stop(p, rx);
if (ret) {
dev_err(&p->pdev->dev, "failed to shut down hardware\n");
return ret;
}
if (rx)
dma_sync_single_for_cpu(p->master->dma_rx->device->dev,
p->rx_dma_addr, len,
DMA_FROM_DEVICE);
return 0;
stop_reset:
sh_msiof_reset_str(p);
sh_msiof_spi_stop(p, rx);
stop_dma:
if (tx)
dmaengine_terminate_all(p->master->dma_tx);
no_dma_tx:
if (rx)
dmaengine_terminate_all(p->master->dma_rx);
sh_msiof_write(p, IER, 0);
return ret;
}
static void copy_bswap32(u32 *dst, const u32 *src, unsigned int words)
{
/* src or dst can be unaligned, but not both */
if ((unsigned long)src & 3) {
while (words--) {
*dst++ = swab32(get_unaligned(src));
src++;
}
} else if ((unsigned long)dst & 3) {
while (words--) {
put_unaligned(swab32(*src++), dst);
dst++;
}
} else {
while (words--)
*dst++ = swab32(*src++);
}
}
static void copy_wswap32(u32 *dst, const u32 *src, unsigned int words)
{
/* src or dst can be unaligned, but not both */
if ((unsigned long)src & 3) {
while (words--) {
*dst++ = swahw32(get_unaligned(src));
src++;
}
} else if ((unsigned long)dst & 3) {
while (words--) {
put_unaligned(swahw32(*src++), dst);
dst++;
}
} else {
while (words--)
*dst++ = swahw32(*src++);
}
}
static void copy_plain32(u32 *dst, const u32 *src, unsigned int words)
{
memcpy(dst, src, words * 4);
}
static int sh_msiof_transfer_one(struct spi_master *master,
struct spi_device *spi,
struct spi_transfer *t)
{
struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
void (*copy32)(u32 *, const u32 *, unsigned int);
void (*tx_fifo)(struct sh_msiof_spi_priv *, const void *, int, int);
void (*rx_fifo)(struct sh_msiof_spi_priv *, void *, int, int);
const void *tx_buf = t->tx_buf;
void *rx_buf = t->rx_buf;
unsigned int len = t->len;
unsigned int bits = t->bits_per_word;
unsigned int bytes_per_word;
unsigned int words;
int n;
bool swab;
int ret;
/* setup clocks (clock already enabled in chipselect()) */
sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk), t->speed_hz);
while (master->dma_tx && len > 15) {
/*
* DMA supports 32-bit words only, hence pack 8-bit and 16-bit
* words, with byte resp. word swapping.
*/
unsigned int l = 0;
if (tx_buf)
l = min(len, p->tx_fifo_size * 4);
if (rx_buf)
l = min(len, p->rx_fifo_size * 4);
if (bits <= 8) {
if (l & 3)
break;
copy32 = copy_bswap32;
} else if (bits <= 16) {
if (l & 1)
break;
copy32 = copy_wswap32;
} else {
copy32 = copy_plain32;
}
if (tx_buf)
copy32(p->tx_dma_page, tx_buf, l / 4);
ret = sh_msiof_dma_once(p, tx_buf, rx_buf, l);
if (ret == -EAGAIN) {
pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
dev_driver_string(&p->pdev->dev),
dev_name(&p->pdev->dev));
break;
}
if (ret)
return ret;
if (rx_buf) {
copy32(rx_buf, p->rx_dma_page, l / 4);
rx_buf += l;
}
if (tx_buf)
tx_buf += l;
len -= l;
if (!len)
return 0;
}
if (bits <= 8 && len > 15 && !(len & 3)) {
bits = 32;
swab = true;
} else {
swab = false;
}
/* setup bytes per word and fifo read/write functions */
if (bits <= 8) {
bytes_per_word = 1;
tx_fifo = sh_msiof_spi_write_fifo_8;
rx_fifo = sh_msiof_spi_read_fifo_8;
} else if (bits <= 16) {
bytes_per_word = 2;
if ((unsigned long)tx_buf & 0x01)
tx_fifo = sh_msiof_spi_write_fifo_16u;
else
tx_fifo = sh_msiof_spi_write_fifo_16;
if ((unsigned long)rx_buf & 0x01)
rx_fifo = sh_msiof_spi_read_fifo_16u;
else
rx_fifo = sh_msiof_spi_read_fifo_16;
} else if (swab) {
bytes_per_word = 4;
if ((unsigned long)tx_buf & 0x03)
tx_fifo = sh_msiof_spi_write_fifo_s32u;
else
tx_fifo = sh_msiof_spi_write_fifo_s32;
if ((unsigned long)rx_buf & 0x03)
rx_fifo = sh_msiof_spi_read_fifo_s32u;
else
rx_fifo = sh_msiof_spi_read_fifo_s32;
} else {
bytes_per_word = 4;
if ((unsigned long)tx_buf & 0x03)
tx_fifo = sh_msiof_spi_write_fifo_32u;
else
tx_fifo = sh_msiof_spi_write_fifo_32;
if ((unsigned long)rx_buf & 0x03)
rx_fifo = sh_msiof_spi_read_fifo_32u;
else
rx_fifo = sh_msiof_spi_read_fifo_32;
}
/* transfer in fifo sized chunks */
words = len / bytes_per_word;
while (words > 0) {
n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo, tx_buf, rx_buf,
words, bits);
if (n < 0)
return n;
if (tx_buf)
tx_buf += n * bytes_per_word;
if (rx_buf)
rx_buf += n * bytes_per_word;
words -= n;
}
return 0;
}
static const struct sh_msiof_chipdata sh_data = {
.tx_fifo_size = 64,
.rx_fifo_size = 64,
.master_flags = 0,
};
static const struct sh_msiof_chipdata r8a779x_data = {
.tx_fifo_size = 64,
.rx_fifo_size = 64,
.master_flags = SPI_MASTER_MUST_TX,
};
static const struct of_device_id sh_msiof_match[] = {
{ .compatible = "renesas,sh-msiof", .data = &sh_data },
{ .compatible = "renesas,sh-mobile-msiof", .data = &sh_data },
{ .compatible = "renesas,msiof-r8a7790", .data = &r8a779x_data },
{ .compatible = "renesas,msiof-r8a7791", .data = &r8a779x_data },
{ .compatible = "renesas,msiof-r8a7792", .data = &r8a779x_data },
{ .compatible = "renesas,msiof-r8a7793", .data = &r8a779x_data },
{ .compatible = "renesas,msiof-r8a7794", .data = &r8a779x_data },
{},
};
MODULE_DEVICE_TABLE(of, sh_msiof_match);
#ifdef CONFIG_OF
static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
{
struct sh_msiof_spi_info *info;
struct device_node *np = dev->of_node;
u32 num_cs = 1;
info = devm_kzalloc(dev, sizeof(struct sh_msiof_spi_info), GFP_KERNEL);
if (!info)
return NULL;
/* Parse the MSIOF properties */
of_property_read_u32(np, "num-cs", &num_cs);
of_property_read_u32(np, "renesas,tx-fifo-size",
&info->tx_fifo_override);
of_property_read_u32(np, "renesas,rx-fifo-size",
&info->rx_fifo_override);
of_property_read_u32(np, "renesas,dtdl", &info->dtdl);
of_property_read_u32(np, "renesas,syncdl", &info->syncdl);
info->num_chipselect = num_cs;
return info;
}
#else
static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
{
return NULL;
}
#endif
static struct dma_chan *sh_msiof_request_dma_chan(struct device *dev,
enum dma_transfer_direction dir, unsigned int id, dma_addr_t port_addr)
{
dma_cap_mask_t mask;
struct dma_chan *chan;
struct dma_slave_config cfg;
int ret;
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
(void *)(unsigned long)id, dev,
dir == DMA_MEM_TO_DEV ? "tx" : "rx");
if (!chan) {
dev_warn(dev, "dma_request_slave_channel_compat failed\n");
return NULL;
}
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_4_BYTES;
} else {
cfg.src_addr = port_addr;
cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
}
ret = dmaengine_slave_config(chan, &cfg);
if (ret) {
dev_warn(dev, "dmaengine_slave_config failed %d\n", ret);
dma_release_channel(chan);
return NULL;
}
return chan;
}
static int sh_msiof_request_dma(struct sh_msiof_spi_priv *p)
{
struct platform_device *pdev = p->pdev;
struct device *dev = &pdev->dev;
const struct sh_msiof_spi_info *info = dev_get_platdata(dev);
unsigned int dma_tx_id, dma_rx_id;
const struct resource *res;
struct spi_master *master;
struct device *tx_dev, *rx_dev;
if (dev->of_node) {
/* In the OF case we will get the slave IDs from the DT */
dma_tx_id = 0;
dma_rx_id = 0;
} else if (info && info->dma_tx_id && info->dma_rx_id) {
dma_tx_id = info->dma_tx_id;
dma_rx_id = info->dma_rx_id;
} else {
/* The driver assumes no error */
return 0;
}
/* The DMA engine uses the second register set, if present */
res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (!res)
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
master = p->master;
master->dma_tx = sh_msiof_request_dma_chan(dev, DMA_MEM_TO_DEV,
dma_tx_id,
res->start + TFDR);
if (!master->dma_tx)
return -ENODEV;
master->dma_rx = sh_msiof_request_dma_chan(dev, DMA_DEV_TO_MEM,
dma_rx_id,
res->start + RFDR);
if (!master->dma_rx)
goto free_tx_chan;
p->tx_dma_page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
if (!p->tx_dma_page)
goto free_rx_chan;
p->rx_dma_page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
if (!p->rx_dma_page)
goto free_tx_page;
tx_dev = master->dma_tx->device->dev;
p->tx_dma_addr = dma_map_single(tx_dev, p->tx_dma_page, PAGE_SIZE,
DMA_TO_DEVICE);
if (dma_mapping_error(tx_dev, p->tx_dma_addr))
goto free_rx_page;
rx_dev = master->dma_rx->device->dev;
p->rx_dma_addr = dma_map_single(rx_dev, p->rx_dma_page, PAGE_SIZE,
DMA_FROM_DEVICE);
if (dma_mapping_error(rx_dev, p->rx_dma_addr))
goto unmap_tx_page;
dev_info(dev, "DMA available");
return 0;
unmap_tx_page:
dma_unmap_single(tx_dev, p->tx_dma_addr, PAGE_SIZE, DMA_TO_DEVICE);
free_rx_page:
free_page((unsigned long)p->rx_dma_page);
free_tx_page:
free_page((unsigned long)p->tx_dma_page);
free_rx_chan:
dma_release_channel(master->dma_rx);
free_tx_chan:
dma_release_channel(master->dma_tx);
master->dma_tx = NULL;
return -ENODEV;
}
static void sh_msiof_release_dma(struct sh_msiof_spi_priv *p)
{
struct spi_master *master = p->master;
struct device *dev;
if (!master->dma_tx)
return;
dev = &p->pdev->dev;
dma_unmap_single(master->dma_rx->device->dev, p->rx_dma_addr,
PAGE_SIZE, DMA_FROM_DEVICE);
dma_unmap_single(master->dma_tx->device->dev, p->tx_dma_addr,
PAGE_SIZE, DMA_TO_DEVICE);
free_page((unsigned long)p->rx_dma_page);
free_page((unsigned long)p->tx_dma_page);
dma_release_channel(master->dma_rx);
dma_release_channel(master->dma_tx);
}
static int sh_msiof_spi_probe(struct platform_device *pdev)
{
struct resource *r;
struct spi_master *master;
const struct of_device_id *of_id;
struct sh_msiof_spi_priv *p;
int i;
int ret;
master = spi_alloc_master(&pdev->dev, sizeof(struct sh_msiof_spi_priv));
if (master == NULL) {
dev_err(&pdev->dev, "failed to allocate spi master\n");
return -ENOMEM;
}
p = spi_master_get_devdata(master);
platform_set_drvdata(pdev, p);
p->master = master;
of_id = of_match_device(sh_msiof_match, &pdev->dev);
if (of_id) {
p->chipdata = of_id->data;
p->info = sh_msiof_spi_parse_dt(&pdev->dev);
} else {
p->chipdata = (const void *)pdev->id_entry->driver_data;
p->info = dev_get_platdata(&pdev->dev);
}
if (!p->info) {
dev_err(&pdev->dev, "failed to obtain device info\n");
ret = -ENXIO;
goto err1;
}
init_completion(&p->done);
p->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(p->clk)) {
dev_err(&pdev->dev, "cannot get clock\n");
ret = PTR_ERR(p->clk);
goto err1;
}
i = platform_get_irq(pdev, 0);
if (i < 0) {
dev_err(&pdev->dev, "cannot get platform IRQ\n");
ret = -ENOENT;
goto err1;
}
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
p->mapbase = devm_ioremap_resource(&pdev->dev, r);
if (IS_ERR(p->mapbase)) {
ret = PTR_ERR(p->mapbase);
goto err1;
}
ret = devm_request_irq(&pdev->dev, i, sh_msiof_spi_irq, 0,
dev_name(&pdev->dev), p);
if (ret) {
dev_err(&pdev->dev, "unable to request irq\n");
goto err1;
}
p->pdev = pdev;
pm_runtime_enable(&pdev->dev);
/* Platform data may override FIFO sizes */
p->tx_fifo_size = p->chipdata->tx_fifo_size;
p->rx_fifo_size = p->chipdata->rx_fifo_size;
if (p->info->tx_fifo_override)
p->tx_fifo_size = p->info->tx_fifo_override;
if (p->info->rx_fifo_override)
p->rx_fifo_size = p->info->rx_fifo_override;
/* init master code */
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
master->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE;
master->flags = p->chipdata->master_flags;
master->bus_num = pdev->id;
master->dev.of_node = pdev->dev.of_node;
master->num_chipselect = p->info->num_chipselect;
master->setup = sh_msiof_spi_setup;
master->prepare_message = sh_msiof_prepare_message;
master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 32);
master->auto_runtime_pm = true;
master->transfer_one = sh_msiof_transfer_one;
ret = sh_msiof_request_dma(p);
if (ret < 0)
dev_warn(&pdev->dev, "DMA not available, using PIO\n");
ret = devm_spi_register_master(&pdev->dev, master);
if (ret < 0) {
dev_err(&pdev->dev, "spi_register_master error.\n");
goto err2;
}
return 0;
err2:
sh_msiof_release_dma(p);
pm_runtime_disable(&pdev->dev);
err1:
spi_master_put(master);
return ret;
}
static int sh_msiof_spi_remove(struct platform_device *pdev)
{
struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev);
sh_msiof_release_dma(p);
pm_runtime_disable(&pdev->dev);
return 0;
}
static const struct platform_device_id spi_driver_ids[] = {
{ "spi_sh_msiof", (kernel_ulong_t)&sh_data },
{},
};
MODULE_DEVICE_TABLE(platform, spi_driver_ids);
static struct platform_driver sh_msiof_spi_drv = {
.probe = sh_msiof_spi_probe,
.remove = sh_msiof_spi_remove,
.id_table = spi_driver_ids,
.driver = {
.name = "spi_sh_msiof",
.of_match_table = of_match_ptr(sh_msiof_match),
},
};
module_platform_driver(sh_msiof_spi_drv);
MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver");
MODULE_AUTHOR("Magnus Damm");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:spi_sh_msiof");