- 根目录:
- drivers
- spi
- spi-tegra20-slink.c
/*
* SPI driver for Nvidia's Tegra20/Tegra30 SLINK Controller.
*
* Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
*/
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/reset.h>
#include <linux/spi/spi.h>
#define SLINK_COMMAND 0x000
#define SLINK_BIT_LENGTH(x) (((x) & 0x1f) << 0)
#define SLINK_WORD_SIZE(x) (((x) & 0x1f) << 5)
#define SLINK_BOTH_EN (1 << 10)
#define SLINK_CS_SW (1 << 11)
#define SLINK_CS_VALUE (1 << 12)
#define SLINK_CS_POLARITY (1 << 13)
#define SLINK_IDLE_SDA_DRIVE_LOW (0 << 16)
#define SLINK_IDLE_SDA_DRIVE_HIGH (1 << 16)
#define SLINK_IDLE_SDA_PULL_LOW (2 << 16)
#define SLINK_IDLE_SDA_PULL_HIGH (3 << 16)
#define SLINK_IDLE_SDA_MASK (3 << 16)
#define SLINK_CS_POLARITY1 (1 << 20)
#define SLINK_CK_SDA (1 << 21)
#define SLINK_CS_POLARITY2 (1 << 22)
#define SLINK_CS_POLARITY3 (1 << 23)
#define SLINK_IDLE_SCLK_DRIVE_LOW (0 << 24)
#define SLINK_IDLE_SCLK_DRIVE_HIGH (1 << 24)
#define SLINK_IDLE_SCLK_PULL_LOW (2 << 24)
#define SLINK_IDLE_SCLK_PULL_HIGH (3 << 24)
#define SLINK_IDLE_SCLK_MASK (3 << 24)
#define SLINK_M_S (1 << 28)
#define SLINK_WAIT (1 << 29)
#define SLINK_GO (1 << 30)
#define SLINK_ENB (1 << 31)
#define SLINK_MODES (SLINK_IDLE_SCLK_MASK | SLINK_CK_SDA)
#define SLINK_COMMAND2 0x004
#define SLINK_LSBFE (1 << 0)
#define SLINK_SSOE (1 << 1)
#define SLINK_SPIE (1 << 4)
#define SLINK_BIDIROE (1 << 6)
#define SLINK_MODFEN (1 << 7)
#define SLINK_INT_SIZE(x) (((x) & 0x1f) << 8)
#define SLINK_CS_ACTIVE_BETWEEN (1 << 17)
#define SLINK_SS_EN_CS(x) (((x) & 0x3) << 18)
#define SLINK_SS_SETUP(x) (((x) & 0x3) << 20)
#define SLINK_FIFO_REFILLS_0 (0 << 22)
#define SLINK_FIFO_REFILLS_1 (1 << 22)
#define SLINK_FIFO_REFILLS_2 (2 << 22)
#define SLINK_FIFO_REFILLS_3 (3 << 22)
#define SLINK_FIFO_REFILLS_MASK (3 << 22)
#define SLINK_WAIT_PACK_INT(x) (((x) & 0x7) << 26)
#define SLINK_SPC0 (1 << 29)
#define SLINK_TXEN (1 << 30)
#define SLINK_RXEN (1 << 31)
#define SLINK_STATUS 0x008
#define SLINK_COUNT(val) (((val) >> 0) & 0x1f)
#define SLINK_WORD(val) (((val) >> 5) & 0x1f)
#define SLINK_BLK_CNT(val) (((val) >> 0) & 0xffff)
#define SLINK_MODF (1 << 16)
#define SLINK_RX_UNF (1 << 18)
#define SLINK_TX_OVF (1 << 19)
#define SLINK_TX_FULL (1 << 20)
#define SLINK_TX_EMPTY (1 << 21)
#define SLINK_RX_FULL (1 << 22)
#define SLINK_RX_EMPTY (1 << 23)
#define SLINK_TX_UNF (1 << 24)
#define SLINK_RX_OVF (1 << 25)
#define SLINK_TX_FLUSH (1 << 26)
#define SLINK_RX_FLUSH (1 << 27)
#define SLINK_SCLK (1 << 28)
#define SLINK_ERR (1 << 29)
#define SLINK_RDY (1 << 30)
#define SLINK_BSY (1 << 31)
#define SLINK_FIFO_ERROR (SLINK_TX_OVF | SLINK_RX_UNF | \
SLINK_TX_UNF | SLINK_RX_OVF)
#define SLINK_FIFO_EMPTY (SLINK_TX_EMPTY | SLINK_RX_EMPTY)
#define SLINK_MAS_DATA 0x010
#define SLINK_SLAVE_DATA 0x014
#define SLINK_DMA_CTL 0x018
#define SLINK_DMA_BLOCK_SIZE(x) (((x) & 0xffff) << 0)
#define SLINK_TX_TRIG_1 (0 << 16)
#define SLINK_TX_TRIG_4 (1 << 16)
#define SLINK_TX_TRIG_8 (2 << 16)
#define SLINK_TX_TRIG_16 (3 << 16)
#define SLINK_TX_TRIG_MASK (3 << 16)
#define SLINK_RX_TRIG_1 (0 << 18)
#define SLINK_RX_TRIG_4 (1 << 18)
#define SLINK_RX_TRIG_8 (2 << 18)
#define SLINK_RX_TRIG_16 (3 << 18)
#define SLINK_RX_TRIG_MASK (3 << 18)
#define SLINK_PACKED (1 << 20)
#define SLINK_PACK_SIZE_4 (0 << 21)
#define SLINK_PACK_SIZE_8 (1 << 21)
#define SLINK_PACK_SIZE_16 (2 << 21)
#define SLINK_PACK_SIZE_32 (3 << 21)
#define SLINK_PACK_SIZE_MASK (3 << 21)
#define SLINK_IE_TXC (1 << 26)
#define SLINK_IE_RXC (1 << 27)
#define SLINK_DMA_EN (1 << 31)
#define SLINK_STATUS2 0x01c
#define SLINK_TX_FIFO_EMPTY_COUNT(val) (((val) & 0x3f) >> 0)
#define SLINK_RX_FIFO_FULL_COUNT(val) (((val) & 0x3f0000) >> 16)
#define SLINK_SS_HOLD_TIME(val) (((val) & 0xF) << 6)
#define SLINK_TX_FIFO 0x100
#define SLINK_RX_FIFO 0x180
#define DATA_DIR_TX (1 << 0)
#define DATA_DIR_RX (1 << 1)
#define SLINK_DMA_TIMEOUT (msecs_to_jiffies(1000))
#define DEFAULT_SPI_DMA_BUF_LEN (16*1024)
#define TX_FIFO_EMPTY_COUNT_MAX SLINK_TX_FIFO_EMPTY_COUNT(0x20)
#define RX_FIFO_FULL_COUNT_ZERO SLINK_RX_FIFO_FULL_COUNT(0)
#define SLINK_STATUS2_RESET \
(TX_FIFO_EMPTY_COUNT_MAX | RX_FIFO_FULL_COUNT_ZERO << 16)
#define MAX_CHIP_SELECT 4
#define SLINK_FIFO_DEPTH 32
struct tegra_slink_chip_data {
bool cs_hold_time;
};
struct tegra_slink_data {
struct device *dev;
struct spi_master *master;
const struct tegra_slink_chip_data *chip_data;
spinlock_t lock;
struct clk *clk;
struct reset_control *rst;
void __iomem *base;
phys_addr_t phys;
unsigned irq;
u32 cur_speed;
struct spi_device *cur_spi;
unsigned cur_pos;
unsigned cur_len;
unsigned words_per_32bit;
unsigned bytes_per_word;
unsigned curr_dma_words;
unsigned cur_direction;
unsigned cur_rx_pos;
unsigned cur_tx_pos;
unsigned dma_buf_size;
unsigned max_buf_size;
bool is_curr_dma_xfer;
struct completion rx_dma_complete;
struct completion tx_dma_complete;
u32 tx_status;
u32 rx_status;
u32 status_reg;
bool is_packed;
u32 packed_size;
u32 command_reg;
u32 command2_reg;
u32 dma_control_reg;
u32 def_command_reg;
u32 def_command2_reg;
struct completion xfer_completion;
struct spi_transfer *curr_xfer;
struct dma_chan *rx_dma_chan;
u32 *rx_dma_buf;
dma_addr_t rx_dma_phys;
struct dma_async_tx_descriptor *rx_dma_desc;
struct dma_chan *tx_dma_chan;
u32 *tx_dma_buf;
dma_addr_t tx_dma_phys;
struct dma_async_tx_descriptor *tx_dma_desc;
};
static int tegra_slink_runtime_suspend(struct device *dev);
static int tegra_slink_runtime_resume(struct device *dev);
static inline u32 tegra_slink_readl(struct tegra_slink_data *tspi,
unsigned long reg)
{
return readl(tspi->base + reg);
}
static inline void tegra_slink_writel(struct tegra_slink_data *tspi,
u32 val, unsigned long reg)
{
writel(val, tspi->base + reg);
/* Read back register to make sure that register writes completed */
if (reg != SLINK_TX_FIFO)
readl(tspi->base + SLINK_MAS_DATA);
}
static void tegra_slink_clear_status(struct tegra_slink_data *tspi)
{
u32 val_write;
tegra_slink_readl(tspi, SLINK_STATUS);
/* Write 1 to clear status register */
val_write = SLINK_RDY | SLINK_FIFO_ERROR;
tegra_slink_writel(tspi, val_write, SLINK_STATUS);
}
static u32 tegra_slink_get_packed_size(struct tegra_slink_data *tspi,
struct spi_transfer *t)
{
switch (tspi->bytes_per_word) {
case 0:
return SLINK_PACK_SIZE_4;
case 1:
return SLINK_PACK_SIZE_8;
case 2:
return SLINK_PACK_SIZE_16;
case 4:
return SLINK_PACK_SIZE_32;
default:
return 0;
}
}
static unsigned tegra_slink_calculate_curr_xfer_param(
struct spi_device *spi, struct tegra_slink_data *tspi,
struct spi_transfer *t)
{
unsigned remain_len = t->len - tspi->cur_pos;
unsigned max_word;
unsigned bits_per_word;
unsigned max_len;
unsigned total_fifo_words;
bits_per_word = t->bits_per_word;
tspi->bytes_per_word = DIV_ROUND_UP(bits_per_word, 8);
if (bits_per_word == 8 || bits_per_word == 16) {
tspi->is_packed = 1;
tspi->words_per_32bit = 32/bits_per_word;
} else {
tspi->is_packed = 0;
tspi->words_per_32bit = 1;
}
tspi->packed_size = tegra_slink_get_packed_size(tspi, t);
if (tspi->is_packed) {
max_len = min(remain_len, tspi->max_buf_size);
tspi->curr_dma_words = max_len/tspi->bytes_per_word;
total_fifo_words = max_len/4;
} else {
max_word = (remain_len - 1) / tspi->bytes_per_word + 1;
max_word = min(max_word, tspi->max_buf_size/4);
tspi->curr_dma_words = max_word;
total_fifo_words = max_word;
}
return total_fifo_words;
}
static unsigned tegra_slink_fill_tx_fifo_from_client_txbuf(
struct tegra_slink_data *tspi, struct spi_transfer *t)
{
unsigned nbytes;
unsigned tx_empty_count;
u32 fifo_status;
unsigned max_n_32bit;
unsigned i, count;
unsigned int written_words;
unsigned fifo_words_left;
u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
fifo_status = tegra_slink_readl(tspi, SLINK_STATUS2);
tx_empty_count = SLINK_TX_FIFO_EMPTY_COUNT(fifo_status);
if (tspi->is_packed) {
fifo_words_left = tx_empty_count * tspi->words_per_32bit;
written_words = min(fifo_words_left, tspi->curr_dma_words);
nbytes = written_words * tspi->bytes_per_word;
max_n_32bit = DIV_ROUND_UP(nbytes, 4);
for (count = 0; count < max_n_32bit; count++) {
u32 x = 0;
for (i = 0; (i < 4) && nbytes; i++, nbytes--)
x |= (u32)(*tx_buf++) << (i * 8);
tegra_slink_writel(tspi, x, SLINK_TX_FIFO);
}
} else {
max_n_32bit = min(tspi->curr_dma_words, tx_empty_count);
written_words = max_n_32bit;
nbytes = written_words * tspi->bytes_per_word;
for (count = 0; count < max_n_32bit; count++) {
u32 x = 0;
for (i = 0; nbytes && (i < tspi->bytes_per_word);
i++, nbytes--)
x |= (u32)(*tx_buf++) << (i * 8);
tegra_slink_writel(tspi, x, SLINK_TX_FIFO);
}
}
tspi->cur_tx_pos += written_words * tspi->bytes_per_word;
return written_words;
}
static unsigned int tegra_slink_read_rx_fifo_to_client_rxbuf(
struct tegra_slink_data *tspi, struct spi_transfer *t)
{
unsigned rx_full_count;
u32 fifo_status;
unsigned i, count;
unsigned int read_words = 0;
unsigned len;
u8 *rx_buf = (u8 *)t->rx_buf + tspi->cur_rx_pos;
fifo_status = tegra_slink_readl(tspi, SLINK_STATUS2);
rx_full_count = SLINK_RX_FIFO_FULL_COUNT(fifo_status);
if (tspi->is_packed) {
len = tspi->curr_dma_words * tspi->bytes_per_word;
for (count = 0; count < rx_full_count; count++) {
u32 x = tegra_slink_readl(tspi, SLINK_RX_FIFO);
for (i = 0; len && (i < 4); i++, len--)
*rx_buf++ = (x >> i*8) & 0xFF;
}
tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
read_words += tspi->curr_dma_words;
} else {
for (count = 0; count < rx_full_count; count++) {
u32 x = tegra_slink_readl(tspi, SLINK_RX_FIFO);
for (i = 0; (i < tspi->bytes_per_word); i++)
*rx_buf++ = (x >> (i*8)) & 0xFF;
}
tspi->cur_rx_pos += rx_full_count * tspi->bytes_per_word;
read_words += rx_full_count;
}
return read_words;
}
static void tegra_slink_copy_client_txbuf_to_spi_txbuf(
struct tegra_slink_data *tspi, struct spi_transfer *t)
{
/* Make the dma buffer to read by cpu */
dma_sync_single_for_cpu(tspi->dev, tspi->tx_dma_phys,
tspi->dma_buf_size, DMA_TO_DEVICE);
if (tspi->is_packed) {
unsigned len = tspi->curr_dma_words * tspi->bytes_per_word;
memcpy(tspi->tx_dma_buf, t->tx_buf + tspi->cur_pos, len);
} else {
unsigned int i;
unsigned int count;
u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
unsigned consume = tspi->curr_dma_words * tspi->bytes_per_word;
for (count = 0; count < tspi->curr_dma_words; count++) {
u32 x = 0;
for (i = 0; consume && (i < tspi->bytes_per_word);
i++, consume--)
x |= (u32)(*tx_buf++) << (i * 8);
tspi->tx_dma_buf[count] = x;
}
}
tspi->cur_tx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
/* Make the dma buffer to read by dma */
dma_sync_single_for_device(tspi->dev, tspi->tx_dma_phys,
tspi->dma_buf_size, DMA_TO_DEVICE);
}
static void tegra_slink_copy_spi_rxbuf_to_client_rxbuf(
struct tegra_slink_data *tspi, struct spi_transfer *t)
{
unsigned len;
/* Make the dma buffer to read by cpu */
dma_sync_single_for_cpu(tspi->dev, tspi->rx_dma_phys,
tspi->dma_buf_size, DMA_FROM_DEVICE);
if (tspi->is_packed) {
len = tspi->curr_dma_words * tspi->bytes_per_word;
memcpy(t->rx_buf + tspi->cur_rx_pos, tspi->rx_dma_buf, len);
} else {
unsigned int i;
unsigned int count;
unsigned char *rx_buf = t->rx_buf + tspi->cur_rx_pos;
u32 rx_mask = ((u32)1 << t->bits_per_word) - 1;
for (count = 0; count < tspi->curr_dma_words; count++) {
u32 x = tspi->rx_dma_buf[count] & rx_mask;
for (i = 0; (i < tspi->bytes_per_word); i++)
*rx_buf++ = (x >> (i*8)) & 0xFF;
}
}
tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
/* Make the dma buffer to read by dma */
dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys,
tspi->dma_buf_size, DMA_FROM_DEVICE);
}
static void tegra_slink_dma_complete(void *args)
{
struct completion *dma_complete = args;
complete(dma_complete);
}
static int tegra_slink_start_tx_dma(struct tegra_slink_data *tspi, int len)
{
reinit_completion(&tspi->tx_dma_complete);
tspi->tx_dma_desc = dmaengine_prep_slave_single(tspi->tx_dma_chan,
tspi->tx_dma_phys, len, DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!tspi->tx_dma_desc) {
dev_err(tspi->dev, "Not able to get desc for Tx\n");
return -EIO;
}
tspi->tx_dma_desc->callback = tegra_slink_dma_complete;
tspi->tx_dma_desc->callback_param = &tspi->tx_dma_complete;
dmaengine_submit(tspi->tx_dma_desc);
dma_async_issue_pending(tspi->tx_dma_chan);
return 0;
}
static int tegra_slink_start_rx_dma(struct tegra_slink_data *tspi, int len)
{
reinit_completion(&tspi->rx_dma_complete);
tspi->rx_dma_desc = dmaengine_prep_slave_single(tspi->rx_dma_chan,
tspi->rx_dma_phys, len, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!tspi->rx_dma_desc) {
dev_err(tspi->dev, "Not able to get desc for Rx\n");
return -EIO;
}
tspi->rx_dma_desc->callback = tegra_slink_dma_complete;
tspi->rx_dma_desc->callback_param = &tspi->rx_dma_complete;
dmaengine_submit(tspi->rx_dma_desc);
dma_async_issue_pending(tspi->rx_dma_chan);
return 0;
}
static int tegra_slink_start_dma_based_transfer(
struct tegra_slink_data *tspi, struct spi_transfer *t)
{
u32 val;
unsigned int len;
int ret = 0;
u32 status;
/* Make sure that Rx and Tx fifo are empty */
status = tegra_slink_readl(tspi, SLINK_STATUS);
if ((status & SLINK_FIFO_EMPTY) != SLINK_FIFO_EMPTY) {
dev_err(tspi->dev, "Rx/Tx fifo are not empty status 0x%08x\n",
(unsigned)status);
return -EIO;
}
val = SLINK_DMA_BLOCK_SIZE(tspi->curr_dma_words - 1);
val |= tspi->packed_size;
if (tspi->is_packed)
len = DIV_ROUND_UP(tspi->curr_dma_words * tspi->bytes_per_word,
4) * 4;
else
len = tspi->curr_dma_words * 4;
/* Set attention level based on length of transfer */
if (len & 0xF)
val |= SLINK_TX_TRIG_1 | SLINK_RX_TRIG_1;
else if (((len) >> 4) & 0x1)
val |= SLINK_TX_TRIG_4 | SLINK_RX_TRIG_4;
else
val |= SLINK_TX_TRIG_8 | SLINK_RX_TRIG_8;
if (tspi->cur_direction & DATA_DIR_TX)
val |= SLINK_IE_TXC;
if (tspi->cur_direction & DATA_DIR_RX)
val |= SLINK_IE_RXC;
tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
tspi->dma_control_reg = val;
if (tspi->cur_direction & DATA_DIR_TX) {
tegra_slink_copy_client_txbuf_to_spi_txbuf(tspi, t);
wmb();
ret = tegra_slink_start_tx_dma(tspi, len);
if (ret < 0) {
dev_err(tspi->dev,
"Starting tx dma failed, err %d\n", ret);
return ret;
}
/* Wait for tx fifo to be fill before starting slink */
status = tegra_slink_readl(tspi, SLINK_STATUS);
while (!(status & SLINK_TX_FULL))
status = tegra_slink_readl(tspi, SLINK_STATUS);
}
if (tspi->cur_direction & DATA_DIR_RX) {
/* Make the dma buffer to read by dma */
dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys,
tspi->dma_buf_size, DMA_FROM_DEVICE);
ret = tegra_slink_start_rx_dma(tspi, len);
if (ret < 0) {
dev_err(tspi->dev,
"Starting rx dma failed, err %d\n", ret);
if (tspi->cur_direction & DATA_DIR_TX)
dmaengine_terminate_all(tspi->tx_dma_chan);
return ret;
}
}
tspi->is_curr_dma_xfer = true;
if (tspi->is_packed) {
val |= SLINK_PACKED;
tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
/* HW need small delay after settign Packed mode */
udelay(1);
}
tspi->dma_control_reg = val;
val |= SLINK_DMA_EN;
tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
return ret;
}
static int tegra_slink_start_cpu_based_transfer(
struct tegra_slink_data *tspi, struct spi_transfer *t)
{
u32 val;
unsigned cur_words;
val = tspi->packed_size;
if (tspi->cur_direction & DATA_DIR_TX)
val |= SLINK_IE_TXC;
if (tspi->cur_direction & DATA_DIR_RX)
val |= SLINK_IE_RXC;
tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
tspi->dma_control_reg = val;
if (tspi->cur_direction & DATA_DIR_TX)
cur_words = tegra_slink_fill_tx_fifo_from_client_txbuf(tspi, t);
else
cur_words = tspi->curr_dma_words;
val |= SLINK_DMA_BLOCK_SIZE(cur_words - 1);
tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
tspi->dma_control_reg = val;
tspi->is_curr_dma_xfer = false;
if (tspi->is_packed) {
val |= SLINK_PACKED;
tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
udelay(1);
wmb();
}
tspi->dma_control_reg = val;
val |= SLINK_DMA_EN;
tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
return 0;
}
static int tegra_slink_init_dma_param(struct tegra_slink_data *tspi,
bool dma_to_memory)
{
struct dma_chan *dma_chan;
u32 *dma_buf;
dma_addr_t dma_phys;
int ret;
struct dma_slave_config dma_sconfig;
dma_chan = dma_request_slave_channel_reason(tspi->dev,
dma_to_memory ? "rx" : "tx");
if (IS_ERR(dma_chan)) {
ret = PTR_ERR(dma_chan);
if (ret != -EPROBE_DEFER)
dev_err(tspi->dev,
"Dma channel is not available: %d\n", ret);
return ret;
}
dma_buf = dma_alloc_coherent(tspi->dev, tspi->dma_buf_size,
&dma_phys, GFP_KERNEL);
if (!dma_buf) {
dev_err(tspi->dev, " Not able to allocate the dma buffer\n");
dma_release_channel(dma_chan);
return -ENOMEM;
}
if (dma_to_memory) {
dma_sconfig.src_addr = tspi->phys + SLINK_RX_FIFO;
dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
dma_sconfig.src_maxburst = 0;
} else {
dma_sconfig.dst_addr = tspi->phys + SLINK_TX_FIFO;
dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
dma_sconfig.dst_maxburst = 0;
}
ret = dmaengine_slave_config(dma_chan, &dma_sconfig);
if (ret)
goto scrub;
if (dma_to_memory) {
tspi->rx_dma_chan = dma_chan;
tspi->rx_dma_buf = dma_buf;
tspi->rx_dma_phys = dma_phys;
} else {
tspi->tx_dma_chan = dma_chan;
tspi->tx_dma_buf = dma_buf;
tspi->tx_dma_phys = dma_phys;
}
return 0;
scrub:
dma_free_coherent(tspi->dev, tspi->dma_buf_size, dma_buf, dma_phys);
dma_release_channel(dma_chan);
return ret;
}
static void tegra_slink_deinit_dma_param(struct tegra_slink_data *tspi,
bool dma_to_memory)
{
u32 *dma_buf;
dma_addr_t dma_phys;
struct dma_chan *dma_chan;
if (dma_to_memory) {
dma_buf = tspi->rx_dma_buf;
dma_chan = tspi->rx_dma_chan;
dma_phys = tspi->rx_dma_phys;
tspi->rx_dma_chan = NULL;
tspi->rx_dma_buf = NULL;
} else {
dma_buf = tspi->tx_dma_buf;
dma_chan = tspi->tx_dma_chan;
dma_phys = tspi->tx_dma_phys;
tspi->tx_dma_buf = NULL;
tspi->tx_dma_chan = NULL;
}
if (!dma_chan)
return;
dma_free_coherent(tspi->dev, tspi->dma_buf_size, dma_buf, dma_phys);
dma_release_channel(dma_chan);
}
static int tegra_slink_start_transfer_one(struct spi_device *spi,
struct spi_transfer *t)
{
struct tegra_slink_data *tspi = spi_master_get_devdata(spi->master);
u32 speed;
u8 bits_per_word;
unsigned total_fifo_words;
int ret;
u32 command;
u32 command2;
bits_per_word = t->bits_per_word;
speed = t->speed_hz;
if (speed != tspi->cur_speed) {
clk_set_rate(tspi->clk, speed * 4);
tspi->cur_speed = speed;
}
tspi->cur_spi = spi;
tspi->cur_pos = 0;
tspi->cur_rx_pos = 0;
tspi->cur_tx_pos = 0;
tspi->curr_xfer = t;
total_fifo_words = tegra_slink_calculate_curr_xfer_param(spi, tspi, t);
command = tspi->command_reg;
command &= ~SLINK_BIT_LENGTH(~0);
command |= SLINK_BIT_LENGTH(bits_per_word - 1);
command2 = tspi->command2_reg;
command2 &= ~(SLINK_RXEN | SLINK_TXEN);
tegra_slink_writel(tspi, command, SLINK_COMMAND);
tspi->command_reg = command;
tspi->cur_direction = 0;
if (t->rx_buf) {
command2 |= SLINK_RXEN;
tspi->cur_direction |= DATA_DIR_RX;
}
if (t->tx_buf) {
command2 |= SLINK_TXEN;
tspi->cur_direction |= DATA_DIR_TX;
}
tegra_slink_writel(tspi, command2, SLINK_COMMAND2);
tspi->command2_reg = command2;
if (total_fifo_words > SLINK_FIFO_DEPTH)
ret = tegra_slink_start_dma_based_transfer(tspi, t);
else
ret = tegra_slink_start_cpu_based_transfer(tspi, t);
return ret;
}
static int tegra_slink_setup(struct spi_device *spi)
{
static const u32 cs_pol_bit[MAX_CHIP_SELECT] = {
SLINK_CS_POLARITY,
SLINK_CS_POLARITY1,
SLINK_CS_POLARITY2,
SLINK_CS_POLARITY3,
};
struct tegra_slink_data *tspi = spi_master_get_devdata(spi->master);
u32 val;
unsigned long flags;
int ret;
dev_dbg(&spi->dev, "setup %d bpw, %scpol, %scpha, %dHz\n",
spi->bits_per_word,
spi->mode & SPI_CPOL ? "" : "~",
spi->mode & SPI_CPHA ? "" : "~",
spi->max_speed_hz);
ret = pm_runtime_get_sync(tspi->dev);
if (ret < 0) {
dev_err(tspi->dev, "pm runtime failed, e = %d\n", ret);
return ret;
}
spin_lock_irqsave(&tspi->lock, flags);
val = tspi->def_command_reg;
if (spi->mode & SPI_CS_HIGH)
val |= cs_pol_bit[spi->chip_select];
else
val &= ~cs_pol_bit[spi->chip_select];
tspi->def_command_reg = val;
tegra_slink_writel(tspi, tspi->def_command_reg, SLINK_COMMAND);
spin_unlock_irqrestore(&tspi->lock, flags);
pm_runtime_put(tspi->dev);
return 0;
}
static int tegra_slink_prepare_message(struct spi_master *master,
struct spi_message *msg)
{
struct tegra_slink_data *tspi = spi_master_get_devdata(master);
struct spi_device *spi = msg->spi;
tegra_slink_clear_status(tspi);
tspi->command_reg = tspi->def_command_reg;
tspi->command_reg |= SLINK_CS_SW | SLINK_CS_VALUE;
tspi->command2_reg = tspi->def_command2_reg;
tspi->command2_reg |= SLINK_SS_EN_CS(spi->chip_select);
tspi->command_reg &= ~SLINK_MODES;
if (spi->mode & SPI_CPHA)
tspi->command_reg |= SLINK_CK_SDA;
if (spi->mode & SPI_CPOL)
tspi->command_reg |= SLINK_IDLE_SCLK_DRIVE_HIGH;
else
tspi->command_reg |= SLINK_IDLE_SCLK_DRIVE_LOW;
return 0;
}
static int tegra_slink_transfer_one(struct spi_master *master,
struct spi_device *spi,
struct spi_transfer *xfer)
{
struct tegra_slink_data *tspi = spi_master_get_devdata(master);
int ret;
reinit_completion(&tspi->xfer_completion);
ret = tegra_slink_start_transfer_one(spi, xfer);
if (ret < 0) {
dev_err(tspi->dev,
"spi can not start transfer, err %d\n", ret);
return ret;
}
ret = wait_for_completion_timeout(&tspi->xfer_completion,
SLINK_DMA_TIMEOUT);
if (WARN_ON(ret == 0)) {
dev_err(tspi->dev,
"spi trasfer timeout, err %d\n", ret);
return -EIO;
}
if (tspi->tx_status)
return tspi->tx_status;
if (tspi->rx_status)
return tspi->rx_status;
return 0;
}
static int tegra_slink_unprepare_message(struct spi_master *master,
struct spi_message *msg)
{
struct tegra_slink_data *tspi = spi_master_get_devdata(master);
tegra_slink_writel(tspi, tspi->def_command_reg, SLINK_COMMAND);
tegra_slink_writel(tspi, tspi->def_command2_reg, SLINK_COMMAND2);
return 0;
}
static irqreturn_t handle_cpu_based_xfer(struct tegra_slink_data *tspi)
{
struct spi_transfer *t = tspi->curr_xfer;
unsigned long flags;
spin_lock_irqsave(&tspi->lock, flags);
if (tspi->tx_status || tspi->rx_status ||
(tspi->status_reg & SLINK_BSY)) {
dev_err(tspi->dev,
"CpuXfer ERROR bit set 0x%x\n", tspi->status_reg);
dev_err(tspi->dev,
"CpuXfer 0x%08x:0x%08x:0x%08x\n", tspi->command_reg,
tspi->command2_reg, tspi->dma_control_reg);
reset_control_assert(tspi->rst);
udelay(2);
reset_control_deassert(tspi->rst);
complete(&tspi->xfer_completion);
goto exit;
}
if (tspi->cur_direction & DATA_DIR_RX)
tegra_slink_read_rx_fifo_to_client_rxbuf(tspi, t);
if (tspi->cur_direction & DATA_DIR_TX)
tspi->cur_pos = tspi->cur_tx_pos;
else
tspi->cur_pos = tspi->cur_rx_pos;
if (tspi->cur_pos == t->len) {
complete(&tspi->xfer_completion);
goto exit;
}
tegra_slink_calculate_curr_xfer_param(tspi->cur_spi, tspi, t);
tegra_slink_start_cpu_based_transfer(tspi, t);
exit:
spin_unlock_irqrestore(&tspi->lock, flags);
return IRQ_HANDLED;
}
static irqreturn_t handle_dma_based_xfer(struct tegra_slink_data *tspi)
{
struct spi_transfer *t = tspi->curr_xfer;
long wait_status;
int err = 0;
unsigned total_fifo_words;
unsigned long flags;
/* Abort dmas if any error */
if (tspi->cur_direction & DATA_DIR_TX) {
if (tspi->tx_status) {
dmaengine_terminate_all(tspi->tx_dma_chan);
err += 1;
} else {
wait_status = wait_for_completion_interruptible_timeout(
&tspi->tx_dma_complete, SLINK_DMA_TIMEOUT);
if (wait_status <= 0) {
dmaengine_terminate_all(tspi->tx_dma_chan);
dev_err(tspi->dev, "TxDma Xfer failed\n");
err += 1;
}
}
}
if (tspi->cur_direction & DATA_DIR_RX) {
if (tspi->rx_status) {
dmaengine_terminate_all(tspi->rx_dma_chan);
err += 2;
} else {
wait_status = wait_for_completion_interruptible_timeout(
&tspi->rx_dma_complete, SLINK_DMA_TIMEOUT);
if (wait_status <= 0) {
dmaengine_terminate_all(tspi->rx_dma_chan);
dev_err(tspi->dev, "RxDma Xfer failed\n");
err += 2;
}
}
}
spin_lock_irqsave(&tspi->lock, flags);
if (err) {
dev_err(tspi->dev,
"DmaXfer: ERROR bit set 0x%x\n", tspi->status_reg);
dev_err(tspi->dev,
"DmaXfer 0x%08x:0x%08x:0x%08x\n", tspi->command_reg,
tspi->command2_reg, tspi->dma_control_reg);
reset_control_assert(tspi->rst);
udelay(2);
reset_control_assert(tspi->rst);
complete(&tspi->xfer_completion);
spin_unlock_irqrestore(&tspi->lock, flags);
return IRQ_HANDLED;
}
if (tspi->cur_direction & DATA_DIR_RX)
tegra_slink_copy_spi_rxbuf_to_client_rxbuf(tspi, t);
if (tspi->cur_direction & DATA_DIR_TX)
tspi->cur_pos = tspi->cur_tx_pos;
else
tspi->cur_pos = tspi->cur_rx_pos;
if (tspi->cur_pos == t->len) {
complete(&tspi->xfer_completion);
goto exit;
}
/* Continue transfer in current message */
total_fifo_words = tegra_slink_calculate_curr_xfer_param(tspi->cur_spi,
tspi, t);
if (total_fifo_words > SLINK_FIFO_DEPTH)
err = tegra_slink_start_dma_based_transfer(tspi, t);
else
err = tegra_slink_start_cpu_based_transfer(tspi, t);
exit:
spin_unlock_irqrestore(&tspi->lock, flags);
return IRQ_HANDLED;
}
static irqreturn_t tegra_slink_isr_thread(int irq, void *context_data)
{
struct tegra_slink_data *tspi = context_data;
if (!tspi->is_curr_dma_xfer)
return handle_cpu_based_xfer(tspi);
return handle_dma_based_xfer(tspi);
}
static irqreturn_t tegra_slink_isr(int irq, void *context_data)
{
struct tegra_slink_data *tspi = context_data;
tspi->status_reg = tegra_slink_readl(tspi, SLINK_STATUS);
if (tspi->cur_direction & DATA_DIR_TX)
tspi->tx_status = tspi->status_reg &
(SLINK_TX_OVF | SLINK_TX_UNF);
if (tspi->cur_direction & DATA_DIR_RX)
tspi->rx_status = tspi->status_reg &
(SLINK_RX_OVF | SLINK_RX_UNF);
tegra_slink_clear_status(tspi);
return IRQ_WAKE_THREAD;
}
static const struct tegra_slink_chip_data tegra30_spi_cdata = {
.cs_hold_time = true,
};
static const struct tegra_slink_chip_data tegra20_spi_cdata = {
.cs_hold_time = false,
};
static const struct of_device_id tegra_slink_of_match[] = {
{ .compatible = "nvidia,tegra30-slink", .data = &tegra30_spi_cdata, },
{ .compatible = "nvidia,tegra20-slink", .data = &tegra20_spi_cdata, },
{}
};
MODULE_DEVICE_TABLE(of, tegra_slink_of_match);
static int tegra_slink_probe(struct platform_device *pdev)
{
struct spi_master *master;
struct tegra_slink_data *tspi;
struct resource *r;
int ret, spi_irq;
const struct tegra_slink_chip_data *cdata = NULL;
const struct of_device_id *match;
match = of_match_device(tegra_slink_of_match, &pdev->dev);
if (!match) {
dev_err(&pdev->dev, "Error: No device match found\n");
return -ENODEV;
}
cdata = match->data;
master = spi_alloc_master(&pdev->dev, sizeof(*tspi));
if (!master) {
dev_err(&pdev->dev, "master allocation failed\n");
return -ENOMEM;
}
/* the spi->mode bits understood by this driver: */
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
master->setup = tegra_slink_setup;
master->prepare_message = tegra_slink_prepare_message;
master->transfer_one = tegra_slink_transfer_one;
master->unprepare_message = tegra_slink_unprepare_message;
master->auto_runtime_pm = true;
master->num_chipselect = MAX_CHIP_SELECT;
platform_set_drvdata(pdev, master);
tspi = spi_master_get_devdata(master);
tspi->master = master;
tspi->dev = &pdev->dev;
tspi->chip_data = cdata;
spin_lock_init(&tspi->lock);
if (of_property_read_u32(tspi->dev->of_node, "spi-max-frequency",
&master->max_speed_hz))
master->max_speed_hz = 25000000; /* 25MHz */
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!r) {
dev_err(&pdev->dev, "No IO memory resource\n");
ret = -ENODEV;
goto exit_free_master;
}
tspi->phys = r->start;
tspi->base = devm_ioremap_resource(&pdev->dev, r);
if (IS_ERR(tspi->base)) {
ret = PTR_ERR(tspi->base);
goto exit_free_master;
}
spi_irq = platform_get_irq(pdev, 0);
tspi->irq = spi_irq;
ret = request_threaded_irq(tspi->irq, tegra_slink_isr,
tegra_slink_isr_thread, IRQF_ONESHOT,
dev_name(&pdev->dev), tspi);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n",
tspi->irq);
goto exit_free_master;
}
tspi->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(tspi->clk)) {
dev_err(&pdev->dev, "can not get clock\n");
ret = PTR_ERR(tspi->clk);
goto exit_free_irq;
}
tspi->rst = devm_reset_control_get(&pdev->dev, "spi");
if (IS_ERR(tspi->rst)) {
dev_err(&pdev->dev, "can not get reset\n");
ret = PTR_ERR(tspi->rst);
goto exit_free_irq;
}
tspi->max_buf_size = SLINK_FIFO_DEPTH << 2;
tspi->dma_buf_size = DEFAULT_SPI_DMA_BUF_LEN;
ret = tegra_slink_init_dma_param(tspi, true);
if (ret < 0)
goto exit_free_irq;
ret = tegra_slink_init_dma_param(tspi, false);
if (ret < 0)
goto exit_rx_dma_free;
tspi->max_buf_size = tspi->dma_buf_size;
init_completion(&tspi->tx_dma_complete);
init_completion(&tspi->rx_dma_complete);
init_completion(&tspi->xfer_completion);
pm_runtime_enable(&pdev->dev);
if (!pm_runtime_enabled(&pdev->dev)) {
ret = tegra_slink_runtime_resume(&pdev->dev);
if (ret)
goto exit_pm_disable;
}
ret = pm_runtime_get_sync(&pdev->dev);
if (ret < 0) {
dev_err(&pdev->dev, "pm runtime get failed, e = %d\n", ret);
goto exit_pm_disable;
}
tspi->def_command_reg = SLINK_M_S;
tspi->def_command2_reg = SLINK_CS_ACTIVE_BETWEEN;
tegra_slink_writel(tspi, tspi->def_command_reg, SLINK_COMMAND);
tegra_slink_writel(tspi, tspi->def_command2_reg, SLINK_COMMAND2);
pm_runtime_put(&pdev->dev);
master->dev.of_node = pdev->dev.of_node;
ret = devm_spi_register_master(&pdev->dev, master);
if (ret < 0) {
dev_err(&pdev->dev, "can not register to master err %d\n", ret);
goto exit_pm_disable;
}
return ret;
exit_pm_disable:
pm_runtime_disable(&pdev->dev);
if (!pm_runtime_status_suspended(&pdev->dev))
tegra_slink_runtime_suspend(&pdev->dev);
tegra_slink_deinit_dma_param(tspi, false);
exit_rx_dma_free:
tegra_slink_deinit_dma_param(tspi, true);
exit_free_irq:
free_irq(spi_irq, tspi);
exit_free_master:
spi_master_put(master);
return ret;
}
static int tegra_slink_remove(struct platform_device *pdev)
{
struct spi_master *master = platform_get_drvdata(pdev);
struct tegra_slink_data *tspi = spi_master_get_devdata(master);
free_irq(tspi->irq, tspi);
if (tspi->tx_dma_chan)
tegra_slink_deinit_dma_param(tspi, false);
if (tspi->rx_dma_chan)
tegra_slink_deinit_dma_param(tspi, true);
pm_runtime_disable(&pdev->dev);
if (!pm_runtime_status_suspended(&pdev->dev))
tegra_slink_runtime_suspend(&pdev->dev);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int tegra_slink_suspend(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
return spi_master_suspend(master);
}
static int tegra_slink_resume(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
struct tegra_slink_data *tspi = spi_master_get_devdata(master);
int ret;
ret = pm_runtime_get_sync(dev);
if (ret < 0) {
dev_err(dev, "pm runtime failed, e = %d\n", ret);
return ret;
}
tegra_slink_writel(tspi, tspi->command_reg, SLINK_COMMAND);
tegra_slink_writel(tspi, tspi->command2_reg, SLINK_COMMAND2);
pm_runtime_put(dev);
return spi_master_resume(master);
}
#endif
static int tegra_slink_runtime_suspend(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
struct tegra_slink_data *tspi = spi_master_get_devdata(master);
/* Flush all write which are in PPSB queue by reading back */
tegra_slink_readl(tspi, SLINK_MAS_DATA);
clk_disable_unprepare(tspi->clk);
return 0;
}
static int tegra_slink_runtime_resume(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
struct tegra_slink_data *tspi = spi_master_get_devdata(master);
int ret;
ret = clk_prepare_enable(tspi->clk);
if (ret < 0) {
dev_err(tspi->dev, "clk_prepare failed: %d\n", ret);
return ret;
}
return 0;
}
static const struct dev_pm_ops slink_pm_ops = {
SET_RUNTIME_PM_OPS(tegra_slink_runtime_suspend,
tegra_slink_runtime_resume, NULL)
SET_SYSTEM_SLEEP_PM_OPS(tegra_slink_suspend, tegra_slink_resume)
};
static struct platform_driver tegra_slink_driver = {
.driver = {
.name = "spi-tegra-slink",
.pm = &slink_pm_ops,
.of_match_table = tegra_slink_of_match,
},
.probe = tegra_slink_probe,
.remove = tegra_slink_remove,
};
module_platform_driver(tegra_slink_driver);
MODULE_ALIAS("platform:spi-tegra-slink");
MODULE_DESCRIPTION("NVIDIA Tegra20/Tegra30 SLINK Controller Driver");
MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
MODULE_LICENSE("GPL v2");