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android_kernel_sony_msm8994.../drivers/spi/spi_s3c64xx.c
Jassi Brar 230d42d422 spi: Add s3c64xx SPI Controller driver 
Each SPI controller has exactly one CS line and as such doesn't
provide for multi-cs. We implement a workaround to support
multi-cs by _not_ configuring the mux'ed CS pin for each SPI
controller. The CS mechanism is assumed to be fully machine
specific - the driver doesn't even assume some GPIO pin is used
to control the CS.

The driver selects between DMA and POLLING mode depending upon
the xfer size - DMA mode for xfers bigger than FIFO size, POLLING
mode otherwise.

The driver has been designed to be capable of running SoCs since
s3c64xx and till date, for that reason some of the register fields
have been passed via, SoC specific, platform data.

Signed-off-by: Jassi Brar <jassi.brar@samsung.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2009-12-17 08:58:17 -07:00

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/* linux/drivers/spi/spi_s3c64xx.c
*
* Copyright (C) 2009 Samsung Electronics Ltd.
* Jaswinder Singh <jassi.brar@samsung.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, or
* (at your option) any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/workqueue.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <mach/dma.h>
#include <plat/spi.h>
/* Registers and bit-fields */
#define S3C64XX_SPI_CH_CFG 0x00
#define S3C64XX_SPI_CLK_CFG 0x04
#define S3C64XX_SPI_MODE_CFG 0x08
#define S3C64XX_SPI_SLAVE_SEL 0x0C
#define S3C64XX_SPI_INT_EN 0x10
#define S3C64XX_SPI_STATUS 0x14
#define S3C64XX_SPI_TX_DATA 0x18
#define S3C64XX_SPI_RX_DATA 0x1C
#define S3C64XX_SPI_PACKET_CNT 0x20
#define S3C64XX_SPI_PENDING_CLR 0x24
#define S3C64XX_SPI_SWAP_CFG 0x28
#define S3C64XX_SPI_FB_CLK 0x2C
#define S3C64XX_SPI_CH_HS_EN (1<<6) /* High Speed Enable */
#define S3C64XX_SPI_CH_SW_RST (1<<5)
#define S3C64XX_SPI_CH_SLAVE (1<<4)
#define S3C64XX_SPI_CPOL_L (1<<3)
#define S3C64XX_SPI_CPHA_B (1<<2)
#define S3C64XX_SPI_CH_RXCH_ON (1<<1)
#define S3C64XX_SPI_CH_TXCH_ON (1<<0)
#define S3C64XX_SPI_CLKSEL_SRCMSK (3<<9)
#define S3C64XX_SPI_CLKSEL_SRCSHFT 9
#define S3C64XX_SPI_ENCLK_ENABLE (1<<8)
#define S3C64XX_SPI_PSR_MASK 0xff
#define S3C64XX_SPI_MODE_CH_TSZ_BYTE (0<<29)
#define S3C64XX_SPI_MODE_CH_TSZ_HALFWORD (1<<29)
#define S3C64XX_SPI_MODE_CH_TSZ_WORD (2<<29)
#define S3C64XX_SPI_MODE_CH_TSZ_MASK (3<<29)
#define S3C64XX_SPI_MODE_BUS_TSZ_BYTE (0<<17)
#define S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD (1<<17)
#define S3C64XX_SPI_MODE_BUS_TSZ_WORD (2<<17)
#define S3C64XX_SPI_MODE_BUS_TSZ_MASK (3<<17)
#define S3C64XX_SPI_MODE_RXDMA_ON (1<<2)
#define S3C64XX_SPI_MODE_TXDMA_ON (1<<1)
#define S3C64XX_SPI_MODE_4BURST (1<<0)
#define S3C64XX_SPI_SLAVE_AUTO (1<<1)
#define S3C64XX_SPI_SLAVE_SIG_INACT (1<<0)
#define S3C64XX_SPI_ACT(c) writel(0, (c)->regs + S3C64XX_SPI_SLAVE_SEL)
#define S3C64XX_SPI_DEACT(c) writel(S3C64XX_SPI_SLAVE_SIG_INACT, \
(c)->regs + S3C64XX_SPI_SLAVE_SEL)
#define S3C64XX_SPI_INT_TRAILING_EN (1<<6)
#define S3C64XX_SPI_INT_RX_OVERRUN_EN (1<<5)
#define S3C64XX_SPI_INT_RX_UNDERRUN_EN (1<<4)
#define S3C64XX_SPI_INT_TX_OVERRUN_EN (1<<3)
#define S3C64XX_SPI_INT_TX_UNDERRUN_EN (1<<2)
#define S3C64XX_SPI_INT_RX_FIFORDY_EN (1<<1)
#define S3C64XX_SPI_INT_TX_FIFORDY_EN (1<<0)
#define S3C64XX_SPI_ST_RX_OVERRUN_ERR (1<<5)
#define S3C64XX_SPI_ST_RX_UNDERRUN_ERR (1<<4)
#define S3C64XX_SPI_ST_TX_OVERRUN_ERR (1<<3)
#define S3C64XX_SPI_ST_TX_UNDERRUN_ERR (1<<2)
#define S3C64XX_SPI_ST_RX_FIFORDY (1<<1)
#define S3C64XX_SPI_ST_TX_FIFORDY (1<<0)
#define S3C64XX_SPI_PACKET_CNT_EN (1<<16)
#define S3C64XX_SPI_PND_TX_UNDERRUN_CLR (1<<4)
#define S3C64XX_SPI_PND_TX_OVERRUN_CLR (1<<3)
#define S3C64XX_SPI_PND_RX_UNDERRUN_CLR (1<<2)
#define S3C64XX_SPI_PND_RX_OVERRUN_CLR (1<<1)
#define S3C64XX_SPI_PND_TRAILING_CLR (1<<0)
#define S3C64XX_SPI_SWAP_RX_HALF_WORD (1<<7)
#define S3C64XX_SPI_SWAP_RX_BYTE (1<<6)
#define S3C64XX_SPI_SWAP_RX_BIT (1<<5)
#define S3C64XX_SPI_SWAP_RX_EN (1<<4)
#define S3C64XX_SPI_SWAP_TX_HALF_WORD (1<<3)
#define S3C64XX_SPI_SWAP_TX_BYTE (1<<2)
#define S3C64XX_SPI_SWAP_TX_BIT (1<<1)
#define S3C64XX_SPI_SWAP_TX_EN (1<<0)
#define S3C64XX_SPI_FBCLK_MSK (3<<0)
#define S3C64XX_SPI_ST_TRLCNTZ(v, i) ((((v) >> (i)->rx_lvl_offset) & \
(((i)->fifo_lvl_mask + 1))) \
? 1 : 0)
#define S3C64XX_SPI_ST_TX_DONE(v, i) ((((v) >> (i)->rx_lvl_offset) & \
(((i)->fifo_lvl_mask + 1) << 1)) \
? 1 : 0)
#define TX_FIFO_LVL(v, i) (((v) >> 6) & (i)->fifo_lvl_mask)
#define RX_FIFO_LVL(v, i) (((v) >> (i)->rx_lvl_offset) & (i)->fifo_lvl_mask)
#define S3C64XX_SPI_MAX_TRAILCNT 0x3ff
#define S3C64XX_SPI_TRAILCNT_OFF 19
#define S3C64XX_SPI_TRAILCNT S3C64XX_SPI_MAX_TRAILCNT
#define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
#define SUSPND (1<<0)
#define SPIBUSY (1<<1)
#define RXBUSY (1<<2)
#define TXBUSY (1<<3)
/**
* struct s3c64xx_spi_driver_data - Runtime info holder for SPI driver.
* @clk: Pointer to the spi clock.
* @master: Pointer to the SPI Protocol master.
* @workqueue: Work queue for the SPI xfer requests.
* @cntrlr_info: Platform specific data for the controller this driver manages.
* @tgl_spi: Pointer to the last CS left untoggled by the cs_change hint.
* @work: Work
* @queue: To log SPI xfer requests.
* @lock: Controller specific lock.
* @state: Set of FLAGS to indicate status.
* @rx_dmach: Controller's DMA channel for Rx.
* @tx_dmach: Controller's DMA channel for Tx.
* @sfr_start: BUS address of SPI controller regs.
* @regs: Pointer to ioremap'ed controller registers.
* @xfer_completion: To indicate completion of xfer task.
* @cur_mode: Stores the active configuration of the controller.
* @cur_bpw: Stores the active bits per word settings.
* @cur_speed: Stores the active xfer clock speed.
*/
struct s3c64xx_spi_driver_data {
void __iomem *regs;
struct clk *clk;
struct platform_device *pdev;
struct spi_master *master;
struct workqueue_struct *workqueue;
struct s3c64xx_spi_cntrlr_info *cntrlr_info;
struct spi_device *tgl_spi;
struct work_struct work;
struct list_head queue;
spinlock_t lock;
enum dma_ch rx_dmach;
enum dma_ch tx_dmach;
unsigned long sfr_start;
struct completion xfer_completion;
unsigned state;
unsigned cur_mode, cur_bpw;
unsigned cur_speed;
};
static struct s3c2410_dma_client s3c64xx_spi_dma_client = {
.name = "samsung-spi-dma",
};
static void flush_fifo(struct s3c64xx_spi_driver_data *sdd)
{
struct s3c64xx_spi_cntrlr_info *sci = sdd->cntrlr_info;
void __iomem *regs = sdd->regs;
unsigned long loops;
u32 val;
writel(0, regs + S3C64XX_SPI_PACKET_CNT);
val = readl(regs + S3C64XX_SPI_CH_CFG);
val |= S3C64XX_SPI_CH_SW_RST;
val &= ~S3C64XX_SPI_CH_HS_EN;
writel(val, regs + S3C64XX_SPI_CH_CFG);
/* Flush TxFIFO*/
loops = msecs_to_loops(1);
do {
val = readl(regs + S3C64XX_SPI_STATUS);
} while (TX_FIFO_LVL(val, sci) && loops--);
/* Flush RxFIFO*/
loops = msecs_to_loops(1);
do {
val = readl(regs + S3C64XX_SPI_STATUS);
if (RX_FIFO_LVL(val, sci))
readl(regs + S3C64XX_SPI_RX_DATA);
else
break;
} while (loops--);
val = readl(regs + S3C64XX_SPI_CH_CFG);
val &= ~S3C64XX_SPI_CH_SW_RST;
writel(val, regs + S3C64XX_SPI_CH_CFG);
val = readl(regs + S3C64XX_SPI_MODE_CFG);
val &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
writel(val, regs + S3C64XX_SPI_MODE_CFG);
val = readl(regs + S3C64XX_SPI_CH_CFG);
val &= ~(S3C64XX_SPI_CH_RXCH_ON | S3C64XX_SPI_CH_TXCH_ON);
writel(val, regs + S3C64XX_SPI_CH_CFG);
}
static void enable_datapath(struct s3c64xx_spi_driver_data *sdd,
struct spi_device *spi,
struct spi_transfer *xfer, int dma_mode)
{
struct s3c64xx_spi_cntrlr_info *sci = sdd->cntrlr_info;
void __iomem *regs = sdd->regs;
u32 modecfg, chcfg;
modecfg = readl(regs + S3C64XX_SPI_MODE_CFG);
modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
chcfg = readl(regs + S3C64XX_SPI_CH_CFG);
chcfg &= ~S3C64XX_SPI_CH_TXCH_ON;
if (dma_mode) {
chcfg &= ~S3C64XX_SPI_CH_RXCH_ON;
} else {
/* Always shift in data in FIFO, even if xfer is Tx only,
* this helps setting PCKT_CNT value for generating clocks
* as exactly needed.
*/
chcfg |= S3C64XX_SPI_CH_RXCH_ON;
writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
| S3C64XX_SPI_PACKET_CNT_EN,
regs + S3C64XX_SPI_PACKET_CNT);
}
if (xfer->tx_buf != NULL) {
sdd->state |= TXBUSY;
chcfg |= S3C64XX_SPI_CH_TXCH_ON;
if (dma_mode) {
modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
s3c2410_dma_config(sdd->tx_dmach, 1);
s3c2410_dma_enqueue(sdd->tx_dmach, (void *)sdd,
xfer->tx_dma, xfer->len);
s3c2410_dma_ctrl(sdd->tx_dmach, S3C2410_DMAOP_START);
} else {
unsigned char *buf = (unsigned char *) xfer->tx_buf;
int i = 0;
while (i < xfer->len)
writeb(buf[i++], regs + S3C64XX_SPI_TX_DATA);
}
}
if (xfer->rx_buf != NULL) {
sdd->state |= RXBUSY;
if (sci->high_speed && sdd->cur_speed >= 30000000UL
&& !(sdd->cur_mode & SPI_CPHA))
chcfg |= S3C64XX_SPI_CH_HS_EN;
if (dma_mode) {
modecfg |= S3C64XX_SPI_MODE_RXDMA_ON;
chcfg |= S3C64XX_SPI_CH_RXCH_ON;
writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
| S3C64XX_SPI_PACKET_CNT_EN,
regs + S3C64XX_SPI_PACKET_CNT);
s3c2410_dma_config(sdd->rx_dmach, 1);
s3c2410_dma_enqueue(sdd->rx_dmach, (void *)sdd,
xfer->rx_dma, xfer->len);
s3c2410_dma_ctrl(sdd->rx_dmach, S3C2410_DMAOP_START);
}
}
writel(modecfg, regs + S3C64XX_SPI_MODE_CFG);
writel(chcfg, regs + S3C64XX_SPI_CH_CFG);
}
static inline void enable_cs(struct s3c64xx_spi_driver_data *sdd,
struct spi_device *spi)
{
struct s3c64xx_spi_csinfo *cs;
if (sdd->tgl_spi != NULL) { /* If last device toggled after mssg */
if (sdd->tgl_spi != spi) { /* if last mssg on diff device */
/* Deselect the last toggled device */
cs = sdd->tgl_spi->controller_data;
cs->set_level(spi->mode & SPI_CS_HIGH ? 0 : 1);
}
sdd->tgl_spi = NULL;
}
cs = spi->controller_data;
cs->set_level(spi->mode & SPI_CS_HIGH ? 1 : 0);
}
static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd,
struct spi_transfer *xfer, int dma_mode)
{
struct s3c64xx_spi_cntrlr_info *sci = sdd->cntrlr_info;
void __iomem *regs = sdd->regs;
unsigned long val;
int ms;
/* millisecs to xfer 'len' bytes @ 'cur_speed' */
ms = xfer->len * 8 * 1000 / sdd->cur_speed;
ms += 5; /* some tolerance */
if (dma_mode) {
val = msecs_to_jiffies(ms) + 10;
val = wait_for_completion_timeout(&sdd->xfer_completion, val);
} else {
val = msecs_to_loops(ms);
do {
val = readl(regs + S3C64XX_SPI_STATUS);
} while (RX_FIFO_LVL(val, sci) < xfer->len && --val);
}
if (!val)
return -EIO;
if (dma_mode) {
u32 status;
/*
* DmaTx returns after simply writing data in the FIFO,
* w/o waiting for real transmission on the bus to finish.
* DmaRx returns only after Dma read data from FIFO which
* needs bus transmission to finish, so we don't worry if
* Xfer involved Rx(with or without Tx).
*/
if (xfer->rx_buf == NULL) {
val = msecs_to_loops(10);
status = readl(regs + S3C64XX_SPI_STATUS);
while ((TX_FIFO_LVL(status, sci)
|| !S3C64XX_SPI_ST_TX_DONE(status, sci))
&& --val) {
cpu_relax();
status = readl(regs + S3C64XX_SPI_STATUS);
}
if (!val)
return -EIO;
}
} else {
unsigned char *buf;
int i;
/* If it was only Tx */
if (xfer->rx_buf == NULL) {
sdd->state &= ~TXBUSY;
return 0;
}
i = 0;
buf = xfer->rx_buf;
while (i < xfer->len)
buf[i++] = readb(regs + S3C64XX_SPI_RX_DATA);
sdd->state &= ~RXBUSY;
}
return 0;
}
static inline void disable_cs(struct s3c64xx_spi_driver_data *sdd,
struct spi_device *spi)
{
struct s3c64xx_spi_csinfo *cs = spi->controller_data;
if (sdd->tgl_spi == spi)
sdd->tgl_spi = NULL;
cs->set_level(spi->mode & SPI_CS_HIGH ? 0 : 1);
}
static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
{
struct s3c64xx_spi_cntrlr_info *sci = sdd->cntrlr_info;
void __iomem *regs = sdd->regs;
u32 val;
/* Disable Clock */
val = readl(regs + S3C64XX_SPI_CLK_CFG);
val &= ~S3C64XX_SPI_ENCLK_ENABLE;
writel(val, regs + S3C64XX_SPI_CLK_CFG);
/* Set Polarity and Phase */
val = readl(regs + S3C64XX_SPI_CH_CFG);
val &= ~(S3C64XX_SPI_CH_SLAVE |
S3C64XX_SPI_CPOL_L |
S3C64XX_SPI_CPHA_B);
if (sdd->cur_mode & SPI_CPOL)
val |= S3C64XX_SPI_CPOL_L;
if (sdd->cur_mode & SPI_CPHA)
val |= S3C64XX_SPI_CPHA_B;
writel(val, regs + S3C64XX_SPI_CH_CFG);
/* Set Channel & DMA Mode */
val = readl(regs + S3C64XX_SPI_MODE_CFG);
val &= ~(S3C64XX_SPI_MODE_BUS_TSZ_MASK
| S3C64XX_SPI_MODE_CH_TSZ_MASK);
switch (sdd->cur_bpw) {
case 32:
val |= S3C64XX_SPI_MODE_BUS_TSZ_WORD;
break;
case 16:
val |= S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD;
break;
default:
val |= S3C64XX_SPI_MODE_BUS_TSZ_BYTE;
break;
}
val |= S3C64XX_SPI_MODE_CH_TSZ_BYTE; /* Always 8bits wide */
writel(val, regs + S3C64XX_SPI_MODE_CFG);
/* Configure Clock */
val = readl(regs + S3C64XX_SPI_CLK_CFG);
val &= ~S3C64XX_SPI_PSR_MASK;
val |= ((clk_get_rate(sci->src_clk) / sdd->cur_speed / 2 - 1)
& S3C64XX_SPI_PSR_MASK);
writel(val, regs + S3C64XX_SPI_CLK_CFG);
/* Enable Clock */
val = readl(regs + S3C64XX_SPI_CLK_CFG);
val |= S3C64XX_SPI_ENCLK_ENABLE;
writel(val, regs + S3C64XX_SPI_CLK_CFG);
}
void s3c64xx_spi_dma_rxcb(struct s3c2410_dma_chan *chan, void *buf_id,
int size, enum s3c2410_dma_buffresult res)
{
struct s3c64xx_spi_driver_data *sdd = buf_id;
unsigned long flags;
spin_lock_irqsave(&sdd->lock, flags);
if (res == S3C2410_RES_OK)
sdd->state &= ~RXBUSY;
else
dev_err(&sdd->pdev->dev, "DmaAbrtRx-%d\n", size);
/* If the other done */
if (!(sdd->state & TXBUSY))
complete(&sdd->xfer_completion);
spin_unlock_irqrestore(&sdd->lock, flags);
}
void s3c64xx_spi_dma_txcb(struct s3c2410_dma_chan *chan, void *buf_id,
int size, enum s3c2410_dma_buffresult res)
{
struct s3c64xx_spi_driver_data *sdd = buf_id;
unsigned long flags;
spin_lock_irqsave(&sdd->lock, flags);
if (res == S3C2410_RES_OK)
sdd->state &= ~TXBUSY;
else
dev_err(&sdd->pdev->dev, "DmaAbrtTx-%d \n", size);
/* If the other done */
if (!(sdd->state & RXBUSY))
complete(&sdd->xfer_completion);
spin_unlock_irqrestore(&sdd->lock, flags);
}
#define XFER_DMAADDR_INVALID DMA_BIT_MASK(32)
static int s3c64xx_spi_map_mssg(struct s3c64xx_spi_driver_data *sdd,
struct spi_message *msg)
{
struct device *dev = &sdd->pdev->dev;
struct spi_transfer *xfer;
if (msg->is_dma_mapped)
return 0;
/* First mark all xfer unmapped */
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
xfer->rx_dma = XFER_DMAADDR_INVALID;
xfer->tx_dma = XFER_DMAADDR_INVALID;
}
/* Map until end or first fail */
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
if (xfer->tx_buf != NULL) {
xfer->tx_dma = dma_map_single(dev, xfer->tx_buf,
xfer->len, DMA_TO_DEVICE);
if (dma_mapping_error(dev, xfer->tx_dma)) {
dev_err(dev, "dma_map_single Tx failed\n");
xfer->tx_dma = XFER_DMAADDR_INVALID;
return -ENOMEM;
}
}
if (xfer->rx_buf != NULL) {
xfer->rx_dma = dma_map_single(dev, xfer->rx_buf,
xfer->len, DMA_FROM_DEVICE);
if (dma_mapping_error(dev, xfer->rx_dma)) {
dev_err(dev, "dma_map_single Rx failed\n");
dma_unmap_single(dev, xfer->tx_dma,
xfer->len, DMA_TO_DEVICE);
xfer->tx_dma = XFER_DMAADDR_INVALID;
xfer->rx_dma = XFER_DMAADDR_INVALID;
return -ENOMEM;
}
}
}
return 0;
}
static void s3c64xx_spi_unmap_mssg(struct s3c64xx_spi_driver_data *sdd,
struct spi_message *msg)
{
struct device *dev = &sdd->pdev->dev;
struct spi_transfer *xfer;
if (msg->is_dma_mapped)
return;
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
if (xfer->rx_buf != NULL
&& xfer->rx_dma != XFER_DMAADDR_INVALID)
dma_unmap_single(dev, xfer->rx_dma,
xfer->len, DMA_FROM_DEVICE);
if (xfer->tx_buf != NULL
&& xfer->tx_dma != XFER_DMAADDR_INVALID)
dma_unmap_single(dev, xfer->tx_dma,
xfer->len, DMA_TO_DEVICE);
}
}
static void handle_msg(struct s3c64xx_spi_driver_data *sdd,
struct spi_message *msg)
{
struct s3c64xx_spi_cntrlr_info *sci = sdd->cntrlr_info;
struct spi_device *spi = msg->spi;
struct s3c64xx_spi_csinfo *cs = spi->controller_data;
struct spi_transfer *xfer;
int status = 0, cs_toggle = 0;
u32 speed;
u8 bpw;
/* If Master's(controller) state differs from that needed by Slave */
if (sdd->cur_speed != spi->max_speed_hz
|| sdd->cur_mode != spi->mode
|| sdd->cur_bpw != spi->bits_per_word) {
sdd->cur_bpw = spi->bits_per_word;
sdd->cur_speed = spi->max_speed_hz;
sdd->cur_mode = spi->mode;
s3c64xx_spi_config(sdd);
}
/* Map all the transfers if needed */
if (s3c64xx_spi_map_mssg(sdd, msg)) {
dev_err(&spi->dev,
"Xfer: Unable to map message buffers!\n");
status = -ENOMEM;
goto out;
}
/* Configure feedback delay */
writel(cs->fb_delay & 0x3, sdd->regs + S3C64XX_SPI_FB_CLK);
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
unsigned long flags;
int use_dma;
INIT_COMPLETION(sdd->xfer_completion);
/* Only BPW and Speed may change across transfers */
bpw = xfer->bits_per_word ? : spi->bits_per_word;
speed = xfer->speed_hz ? : spi->max_speed_hz;
if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) {
sdd->cur_bpw = bpw;
sdd->cur_speed = speed;
s3c64xx_spi_config(sdd);
}
/* Polling method for xfers not bigger than FIFO capacity */
if (xfer->len <= ((sci->fifo_lvl_mask >> 1) + 1))
use_dma = 0;
else
use_dma = 1;
spin_lock_irqsave(&sdd->lock, flags);
/* Pending only which is to be done */
sdd->state &= ~RXBUSY;
sdd->state &= ~TXBUSY;
enable_datapath(sdd, spi, xfer, use_dma);
/* Slave Select */
enable_cs(sdd, spi);
/* Start the signals */
S3C64XX_SPI_ACT(sdd);
spin_unlock_irqrestore(&sdd->lock, flags);
status = wait_for_xfer(sdd, xfer, use_dma);
/* Quiese the signals */
S3C64XX_SPI_DEACT(sdd);
if (status) {
dev_err(&spi->dev, "I/O Error: \
rx-%d tx-%d res:rx-%c tx-%c len-%d\n",
xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
(sdd->state & RXBUSY) ? 'f' : 'p',
(sdd->state & TXBUSY) ? 'f' : 'p',
xfer->len);
if (use_dma) {
if (xfer->tx_buf != NULL
&& (sdd->state & TXBUSY))
s3c2410_dma_ctrl(sdd->tx_dmach,
S3C2410_DMAOP_FLUSH);
if (xfer->rx_buf != NULL
&& (sdd->state & RXBUSY))
s3c2410_dma_ctrl(sdd->rx_dmach,
S3C2410_DMAOP_FLUSH);
}
goto out;
}
if (xfer->delay_usecs)
udelay(xfer->delay_usecs);
if (xfer->cs_change) {
/* Hint that the next mssg is gonna be
for the same device */
if (list_is_last(&xfer->transfer_list,
&msg->transfers))
cs_toggle = 1;
else
disable_cs(sdd, spi);
}
msg->actual_length += xfer->len;
flush_fifo(sdd);
}
out:
if (!cs_toggle || status)
disable_cs(sdd, spi);
else
sdd->tgl_spi = spi;
s3c64xx_spi_unmap_mssg(sdd, msg);
msg->status = status;
if (msg->complete)
msg->complete(msg->context);
}
static int acquire_dma(struct s3c64xx_spi_driver_data *sdd)
{
if (s3c2410_dma_request(sdd->rx_dmach,
&s3c64xx_spi_dma_client, NULL) < 0) {
dev_err(&sdd->pdev->dev, "cannot get RxDMA\n");
return 0;
}
s3c2410_dma_set_buffdone_fn(sdd->rx_dmach, s3c64xx_spi_dma_rxcb);
s3c2410_dma_devconfig(sdd->rx_dmach, S3C2410_DMASRC_HW,
sdd->sfr_start + S3C64XX_SPI_RX_DATA);
if (s3c2410_dma_request(sdd->tx_dmach,
&s3c64xx_spi_dma_client, NULL) < 0) {
dev_err(&sdd->pdev->dev, "cannot get TxDMA\n");
s3c2410_dma_free(sdd->rx_dmach, &s3c64xx_spi_dma_client);
return 0;
}
s3c2410_dma_set_buffdone_fn(sdd->tx_dmach, s3c64xx_spi_dma_txcb);
s3c2410_dma_devconfig(sdd->tx_dmach, S3C2410_DMASRC_MEM,
sdd->sfr_start + S3C64XX_SPI_TX_DATA);
return 1;
}
static void s3c64xx_spi_work(struct work_struct *work)
{
struct s3c64xx_spi_driver_data *sdd = container_of(work,
struct s3c64xx_spi_driver_data, work);
unsigned long flags;
/* Acquire DMA channels */
while (!acquire_dma(sdd))
msleep(10);
spin_lock_irqsave(&sdd->lock, flags);
while (!list_empty(&sdd->queue)
&& !(sdd->state & SUSPND)) {
struct spi_message *msg;
msg = container_of(sdd->queue.next, struct spi_message, queue);
list_del_init(&msg->queue);
/* Set Xfer busy flag */
sdd->state |= SPIBUSY;
spin_unlock_irqrestore(&sdd->lock, flags);
handle_msg(sdd, msg);
spin_lock_irqsave(&sdd->lock, flags);
sdd->state &= ~SPIBUSY;
}
spin_unlock_irqrestore(&sdd->lock, flags);
/* Free DMA channels */
s3c2410_dma_free(sdd->tx_dmach, &s3c64xx_spi_dma_client);
s3c2410_dma_free(sdd->rx_dmach, &s3c64xx_spi_dma_client);
}
static int s3c64xx_spi_transfer(struct spi_device *spi,
struct spi_message *msg)
{
struct s3c64xx_spi_driver_data *sdd;
unsigned long flags;
sdd = spi_master_get_devdata(spi->master);
spin_lock_irqsave(&sdd->lock, flags);
if (sdd->state & SUSPND) {
spin_unlock_irqrestore(&sdd->lock, flags);
return -ESHUTDOWN;
}
msg->status = -EINPROGRESS;
msg->actual_length = 0;
list_add_tail(&msg->queue, &sdd->queue);
queue_work(sdd->workqueue, &sdd->work);
spin_unlock_irqrestore(&sdd->lock, flags);
return 0;
}
/*
* Here we only check the validity of requested configuration
* and save the configuration in a local data-structure.
* The controller is actually configured only just before we
* get a message to transfer.
*/
static int s3c64xx_spi_setup(struct spi_device *spi)
{
struct s3c64xx_spi_csinfo *cs = spi->controller_data;
struct s3c64xx_spi_driver_data *sdd;
struct s3c64xx_spi_cntrlr_info *sci;
struct spi_message *msg;
u32 psr, speed;
unsigned long flags;
int err = 0;
if (cs == NULL || cs->set_level == NULL) {
dev_err(&spi->dev, "No CS for SPI(%d)\n", spi->chip_select);
return -ENODEV;
}
sdd = spi_master_get_devdata(spi->master);
sci = sdd->cntrlr_info;
spin_lock_irqsave(&sdd->lock, flags);
list_for_each_entry(msg, &sdd->queue, queue) {
/* Is some mssg is already queued for this device */
if (msg->spi == spi) {
dev_err(&spi->dev,
"setup: attempt while mssg in queue!\n");
spin_unlock_irqrestore(&sdd->lock, flags);
return -EBUSY;
}
}
if (sdd->state & SUSPND) {
spin_unlock_irqrestore(&sdd->lock, flags);
dev_err(&spi->dev,
"setup: SPI-%d not active!\n", spi->master->bus_num);
return -ESHUTDOWN;
}
spin_unlock_irqrestore(&sdd->lock, flags);
if (spi->bits_per_word != 8
&& spi->bits_per_word != 16
&& spi->bits_per_word != 32) {
dev_err(&spi->dev, "setup: %dbits/wrd not supported!\n",
spi->bits_per_word);
err = -EINVAL;
goto setup_exit;
}
/* Check if we can provide the requested rate */
speed = clk_get_rate(sci->src_clk) / 2 / (0 + 1); /* Max possible */
if (spi->max_speed_hz > speed)
spi->max_speed_hz = speed;
psr = clk_get_rate(sci->src_clk) / 2 / spi->max_speed_hz - 1;
psr &= S3C64XX_SPI_PSR_MASK;
if (psr == S3C64XX_SPI_PSR_MASK)
psr--;
speed = clk_get_rate(sci->src_clk) / 2 / (psr + 1);
if (spi->max_speed_hz < speed) {
if (psr+1 < S3C64XX_SPI_PSR_MASK) {
psr++;
} else {
err = -EINVAL;
goto setup_exit;
}
}
speed = clk_get_rate(sci->src_clk) / 2 / (psr + 1);
if (spi->max_speed_hz >= speed)
spi->max_speed_hz = speed;
else
err = -EINVAL;
setup_exit:
/* setup() returns with device de-selected */
disable_cs(sdd, spi);
return err;
}
static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd, int channel)
{
struct s3c64xx_spi_cntrlr_info *sci = sdd->cntrlr_info;
void __iomem *regs = sdd->regs;
unsigned int val;
sdd->cur_speed = 0;
S3C64XX_SPI_DEACT(sdd);
/* Disable Interrupts - we use Polling if not DMA mode */
writel(0, regs + S3C64XX_SPI_INT_EN);
writel(sci->src_clk_nr << S3C64XX_SPI_CLKSEL_SRCSHFT,
regs + S3C64XX_SPI_CLK_CFG);
writel(0, regs + S3C64XX_SPI_MODE_CFG);
writel(0, regs + S3C64XX_SPI_PACKET_CNT);
/* Clear any irq pending bits */
writel(readl(regs + S3C64XX_SPI_PENDING_CLR),
regs + S3C64XX_SPI_PENDING_CLR);
writel(0, regs + S3C64XX_SPI_SWAP_CFG);
val = readl(regs + S3C64XX_SPI_MODE_CFG);
val &= ~S3C64XX_SPI_MODE_4BURST;
val &= ~(S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
val |= (S3C64XX_SPI_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
writel(val, regs + S3C64XX_SPI_MODE_CFG);
flush_fifo(sdd);
}
static int __init s3c64xx_spi_probe(struct platform_device *pdev)
{
struct resource *mem_res, *dmatx_res, *dmarx_res;
struct s3c64xx_spi_driver_data *sdd;
struct s3c64xx_spi_cntrlr_info *sci;
struct spi_master *master;
int ret;
if (pdev->id < 0) {
dev_err(&pdev->dev,
"Invalid platform device id-%d\n", pdev->id);
return -ENODEV;
}
if (pdev->dev.platform_data == NULL) {
dev_err(&pdev->dev, "platform_data missing!\n");
return -ENODEV;
}
/* Check for availability of necessary resource */
dmatx_res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
if (dmatx_res == NULL) {
dev_err(&pdev->dev, "Unable to get SPI-Tx dma resource\n");
return -ENXIO;
}
dmarx_res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
if (dmarx_res == NULL) {
dev_err(&pdev->dev, "Unable to get SPI-Rx dma resource\n");
return -ENXIO;
}
mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (mem_res == NULL) {
dev_err(&pdev->dev, "Unable to get SPI MEM resource\n");
return -ENXIO;
}
master = spi_alloc_master(&pdev->dev,
sizeof(struct s3c64xx_spi_driver_data));
if (master == NULL) {
dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
return -ENOMEM;
}
sci = pdev->dev.platform_data;
platform_set_drvdata(pdev, master);
sdd = spi_master_get_devdata(master);
sdd->master = master;
sdd->cntrlr_info = sci;
sdd->pdev = pdev;
sdd->sfr_start = mem_res->start;
sdd->tx_dmach = dmatx_res->start;
sdd->rx_dmach = dmarx_res->start;
sdd->cur_bpw = 8;
master->bus_num = pdev->id;
master->setup = s3c64xx_spi_setup;
master->transfer = s3c64xx_spi_transfer;
master->num_chipselect = sci->num_cs;
master->dma_alignment = 8;
/* the spi->mode bits understood by this driver: */
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
if (request_mem_region(mem_res->start,
resource_size(mem_res), pdev->name) == NULL) {
dev_err(&pdev->dev, "Req mem region failed\n");
ret = -ENXIO;
goto err0;
}
sdd->regs = ioremap(mem_res->start, resource_size(mem_res));
if (sdd->regs == NULL) {
dev_err(&pdev->dev, "Unable to remap IO\n");
ret = -ENXIO;
goto err1;
}
if (sci->cfg_gpio == NULL || sci->cfg_gpio(pdev)) {
dev_err(&pdev->dev, "Unable to config gpio\n");
ret = -EBUSY;
goto err2;
}
/* Setup clocks */
sdd->clk = clk_get(&pdev->dev, "spi");
if (IS_ERR(sdd->clk)) {
dev_err(&pdev->dev, "Unable to acquire clock 'spi'\n");
ret = PTR_ERR(sdd->clk);
goto err3;
}
if (clk_enable(sdd->clk)) {
dev_err(&pdev->dev, "Couldn't enable clock 'spi'\n");
ret = -EBUSY;
goto err4;
}
if (sci->src_clk_nr == S3C64XX_SPI_SRCCLK_PCLK)
sci->src_clk = sdd->clk;
else
sci->src_clk = clk_get(&pdev->dev, sci->src_clk_name);
if (IS_ERR(sci->src_clk)) {
dev_err(&pdev->dev,
"Unable to acquire clock '%s'\n", sci->src_clk_name);
ret = PTR_ERR(sci->src_clk);
goto err5;
}
if (sci->src_clk != sdd->clk && clk_enable(sci->src_clk)) {
dev_err(&pdev->dev, "Couldn't enable clock '%s'\n",
sci->src_clk_name);
ret = -EBUSY;
goto err6;
}
sdd->workqueue = create_singlethread_workqueue(
dev_name(master->dev.parent));
if (sdd->workqueue == NULL) {
dev_err(&pdev->dev, "Unable to create workqueue\n");
ret = -ENOMEM;
goto err7;
}
/* Setup Deufult Mode */
s3c64xx_spi_hwinit(sdd, pdev->id);
spin_lock_init(&sdd->lock);
init_completion(&sdd->xfer_completion);
INIT_WORK(&sdd->work, s3c64xx_spi_work);
INIT_LIST_HEAD(&sdd->queue);
if (spi_register_master(master)) {
dev_err(&pdev->dev, "cannot register SPI master\n");
ret = -EBUSY;
goto err8;
}
dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d \
with %d Slaves attached\n",
pdev->id, master->num_chipselect);
dev_dbg(&pdev->dev, "\tIOmem=[0x%x-0x%x]\
\tDMA=[Rx-%d, Tx-%d]\n",
mem_res->end, mem_res->start,
sdd->rx_dmach, sdd->tx_dmach);
return 0;
err8:
destroy_workqueue(sdd->workqueue);
err7:
if (sci->src_clk != sdd->clk)
clk_disable(sci->src_clk);
err6:
if (sci->src_clk != sdd->clk)
clk_put(sci->src_clk);
err5:
clk_disable(sdd->clk);
err4:
clk_put(sdd->clk);
err3:
err2:
iounmap((void *) sdd->regs);
err1:
release_mem_region(mem_res->start, resource_size(mem_res));
err0:
platform_set_drvdata(pdev, NULL);
spi_master_put(master);
return ret;
}
static int s3c64xx_spi_remove(struct platform_device *pdev)
{
struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
struct s3c64xx_spi_cntrlr_info *sci = sdd->cntrlr_info;
struct resource *mem_res;
unsigned long flags;
spin_lock_irqsave(&sdd->lock, flags);
sdd->state |= SUSPND;
spin_unlock_irqrestore(&sdd->lock, flags);
while (sdd->state & SPIBUSY)
msleep(10);
spi_unregister_master(master);
destroy_workqueue(sdd->workqueue);
if (sci->src_clk != sdd->clk)
clk_disable(sci->src_clk);
if (sci->src_clk != sdd->clk)
clk_put(sci->src_clk);
clk_disable(sdd->clk);
clk_put(sdd->clk);
iounmap((void *) sdd->regs);
mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(mem_res->start, resource_size(mem_res));
platform_set_drvdata(pdev, NULL);
spi_master_put(master);
return 0;
}
#ifdef CONFIG_PM
static int s3c64xx_spi_suspend(struct platform_device *pdev, pm_message_t state)
{
struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
struct s3c64xx_spi_cntrlr_info *sci = sdd->cntrlr_info;
struct s3c64xx_spi_csinfo *cs;
unsigned long flags;
spin_lock_irqsave(&sdd->lock, flags);
sdd->state |= SUSPND;
spin_unlock_irqrestore(&sdd->lock, flags);
while (sdd->state & SPIBUSY)
msleep(10);
/* Disable the clock */
if (sci->src_clk != sdd->clk)
clk_disable(sci->src_clk);
clk_disable(sdd->clk);
sdd->cur_speed = 0; /* Output Clock is stopped */
return 0;
}
static int s3c64xx_spi_resume(struct platform_device *pdev)
{
struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
struct s3c64xx_spi_cntrlr_info *sci = sdd->cntrlr_info;
unsigned long flags;
sci->cfg_gpio(pdev);
/* Enable the clock */
if (sci->src_clk != sdd->clk)
clk_enable(sci->src_clk);
clk_enable(sdd->clk);
s3c64xx_spi_hwinit(sdd, pdev->id);
spin_lock_irqsave(&sdd->lock, flags);
sdd->state &= ~SUSPND;
spin_unlock_irqrestore(&sdd->lock, flags);
return 0;
}
#else
#define s3c64xx_spi_suspend NULL
#define s3c64xx_spi_resume NULL
#endif /* CONFIG_PM */
static struct platform_driver s3c64xx_spi_driver = {
.driver = {
.name = "s3c64xx-spi",
.owner = THIS_MODULE,
},
.remove = s3c64xx_spi_remove,
.suspend = s3c64xx_spi_suspend,
.resume = s3c64xx_spi_resume,
};
MODULE_ALIAS("platform:s3c64xx-spi");
static int __init s3c64xx_spi_init(void)
{
return platform_driver_probe(&s3c64xx_spi_driver, s3c64xx_spi_probe);
}
module_init(s3c64xx_spi_init);
static void __exit s3c64xx_spi_exit(void)
{
platform_driver_unregister(&s3c64xx_spi_driver);
}
module_exit(s3c64xx_spi_exit);
MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>");
MODULE_DESCRIPTION("S3C64XX SPI Controller Driver");
MODULE_LICENSE("GPL");
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