/*
* SPI driver for NVIDIA's Tegra114 SPI Controller.
*
* Copyright (c) 2013, 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 SPI_COMMAND1 0x000
#define SPI_BIT_LENGTH(x) (((x) & 0x1f) << 0)
#define SPI_PACKED (1 << 5)
#define SPI_TX_EN (1 << 11)
#define SPI_RX_EN (1 << 12)
#define SPI_BOTH_EN_BYTE (1 << 13)
#define SPI_BOTH_EN_BIT (1 << 14)
#define SPI_LSBYTE_FE (1 << 15)
#define SPI_LSBIT_FE (1 << 16)
#define SPI_BIDIROE (1 << 17)
#define SPI_IDLE_SDA_DRIVE_LOW (0 << 18)
#define SPI_IDLE_SDA_DRIVE_HIGH (1 << 18)
#define SPI_IDLE_SDA_PULL_LOW (2 << 18)
#define SPI_IDLE_SDA_PULL_HIGH (3 << 18)
#define SPI_IDLE_SDA_MASK (3 << 18)
#define SPI_CS_SS_VAL (1 << 20)
#define SPI_CS_SW_HW (1 << 21)
/* SPI_CS_POL_INACTIVE bits are default high */
/* n from 0 to 3 */
#define SPI_CS_POL_INACTIVE(n) (1 << (22 + (n)))
#define SPI_CS_POL_INACTIVE_MASK (0xF << 22)
#define SPI_CS_SEL_0 (0 << 26)
#define SPI_CS_SEL_1 (1 << 26)
#define SPI_CS_SEL_2 (2 << 26)
#define SPI_CS_SEL_3 (3 << 26)
#define SPI_CS_SEL_MASK (3 << 26)
#define SPI_CS_SEL(x) (((x) & 0x3) << 26)
#define SPI_CONTROL_MODE_0 (0 << 28)
#define SPI_CONTROL_MODE_1 (1 << 28)
#define SPI_CONTROL_MODE_2 (2 << 28)
#define SPI_CONTROL_MODE_3 (3 << 28)
#define SPI_CONTROL_MODE_MASK (3 << 28)
#define SPI_MODE_SEL(x) (((x) & 0x3) << 28)
#define SPI_M_S (1 << 30)
#define SPI_PIO (1 << 31)
#define SPI_COMMAND2 0x004
#define SPI_TX_TAP_DELAY(x) (((x) & 0x3F) << 6)
#define SPI_RX_TAP_DELAY(x) (((x) & 0x3F) << 0)
#define SPI_CS_TIMING1 0x008
#define SPI_SETUP_HOLD(setup, hold) (((setup) << 4) | (hold))
#define SPI_CS_SETUP_HOLD(reg, cs, val) \
((((val) & 0xFFu) << ((cs) * 8)) | \
((reg) & ~(0xFFu << ((cs) * 8))))
#define SPI_CS_TIMING2 0x00C
#define CYCLES_BETWEEN_PACKETS_0(x) (((x) & 0x1F) << 0)
#define CS_ACTIVE_BETWEEN_PACKETS_0 (1 << 5)
#define CYCLES_BETWEEN_PACKETS_1(x) (((x) & 0x1F) << 8)
#define CS_ACTIVE_BETWEEN_PACKETS_1 (1 << 13)
#define CYCLES_BETWEEN_PACKETS_2(x) (((x) & 0x1F) << 16)
#define CS_ACTIVE_BETWEEN_PACKETS_2 (1 << 21)
#define CYCLES_BETWEEN_PACKETS_3(x) (((x) & 0x1F) << 24)
#define CS_ACTIVE_BETWEEN_PACKETS_3 (1 << 29)
#define SPI_SET_CS_ACTIVE_BETWEEN_PACKETS(reg, cs, val) \
(reg = (((val) & 0x1) << ((cs) * 8 + 5)) | \
((reg) & ~(1 << ((cs) * 8 + 5))))
#define SPI_SET_CYCLES_BETWEEN_PACKETS(reg, cs, val) \
(reg = (((val) & 0xF) << ((cs) * 8)) | \
((reg) & ~(0xF << ((cs) * 8))))
#define SPI_TRANS_STATUS 0x010
#define SPI_BLK_CNT(val) (((val) >> 0) & 0xFFFF)
#define SPI_SLV_IDLE_COUNT(val) (((val) >> 16) & 0xFF)
#define SPI_RDY (1 << 30)
#define SPI_FIFO_STATUS 0x014
#define SPI_RX_FIFO_EMPTY (1 << 0)
#define SPI_RX_FIFO_FULL (1 << 1)
#define SPI_TX_FIFO_EMPTY (1 << 2)
#define SPI_TX_FIFO_FULL (1 << 3)
#define SPI_RX_FIFO_UNF (1 << 4)
#define SPI_RX_FIFO_OVF (1 << 5)
#define SPI_TX_FIFO_UNF (1 << 6)
#define SPI_TX_FIFO_OVF (1 << 7)
#define SPI_ERR (1 << 8)
#define SPI_TX_FIFO_FLUSH (1 << 14)
#define SPI_RX_FIFO_FLUSH (1 << 15)
#define SPI_TX_FIFO_EMPTY_COUNT(val) (((val) >> 16) & 0x7F)
#define SPI_RX_FIFO_FULL_COUNT(val) (((val) >> 23) & 0x7F)
#define SPI_FRAME_END (1 << 30)
#define SPI_CS_INACTIVE (1 << 31)
#define SPI_FIFO_ERROR (SPI_RX_FIFO_UNF | \
SPI_RX_FIFO_OVF | SPI_TX_FIFO_UNF | SPI_TX_FIFO_OVF)
#define SPI_FIFO_EMPTY (SPI_RX_FIFO_EMPTY | SPI_TX_FIFO_EMPTY)
#define SPI_TX_DATA 0x018
#define SPI_RX_DATA 0x01C
#define SPI_DMA_CTL 0x020
#define SPI_TX_TRIG_1 (0 << 15)
#define SPI_TX_TRIG_4 (1 << 15)
#define SPI_TX_TRIG_8 (2 << 15)
#define SPI_TX_TRIG_16 (3 << 15)
#define SPI_TX_TRIG_MASK (3 << 15)
#define SPI_RX_TRIG_1 (0 << 19)
#define SPI_RX_TRIG_4 (1 << 19)
#define SPI_RX_TRIG_8 (2 << 19)
#define SPI_RX_TRIG_16 (3 << 19)
#define SPI_RX_TRIG_MASK (3 << 19)
#define SPI_IE_TX (1 << 28)
#define SPI_IE_RX (1 << 29)
#define SPI_CONT (1 << 30)
#define SPI_DMA (1 << 31)
#define SPI_DMA_EN SPI_DMA
#define SPI_DMA_BLK 0x024
#define SPI_DMA_BLK_SET(x) (((x) & 0xFFFF) << 0)
#define SPI_TX_FIFO 0x108
#define SPI_RX_FIFO 0x188
#define MAX_CHIP_SELECT 4
#define SPI_FIFO_DEPTH 64
#define DATA_DIR_TX (1 << 0)
#define DATA_DIR_RX (1 << 1)
#define SPI_DMA_TIMEOUT (msecs_to_jiffies(1000))
#define DEFAULT_SPI_DMA_BUF_LEN (16*1024)
#define TX_FIFO_EMPTY_COUNT_MAX SPI_TX_FIFO_EMPTY_COUNT(0x40)
#define RX_FIFO_FULL_COUNT_ZERO SPI_RX_FIFO_FULL_COUNT(0)
#define MAX_HOLD_CYCLES 16
#define SPI_DEFAULT_SPEED 25000000
struct tegra_spi_data {
struct device *dev;
struct spi_master *master;
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;
struct spi_device *cs_control;
unsigned cur_pos;
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 command1_reg;
u32 dma_control_reg;
u32 def_command1_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_spi_runtime_suspend(struct device *dev);
static int tegra_spi_runtime_resume(struct device *dev);
static inline u32 tegra_spi_readl(struct tegra_spi_data *tspi,
unsigned long reg)
{
return readl(tspi->base + reg);
}
static inline void tegra_spi_writel(struct tegra_spi_data *tspi,
u32 val, unsigned long reg)
{
writel(val, tspi->base + reg);
/* Read back register to make sure that register writes completed */
if (reg != SPI_TX_FIFO)
readl(tspi->base + SPI_COMMAND1);
}
static void tegra_spi_clear_status(struct tegra_spi_data *tspi)
{
u32 val;
/* Write 1 to clear status register */
val = tegra_spi_readl(tspi, SPI_TRANS_STATUS);
tegra_spi_writel(tspi, val, SPI_TRANS_STATUS);
/* Clear fifo status error if any */
val = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
if (val & SPI_ERR)
tegra_spi_writel(tspi, SPI_ERR | SPI_FIFO_ERROR,
SPI_FIFO_STATUS);
}
static unsigned tegra_spi_calculate_curr_xfer_param(
struct spi_device *spi, struct tegra_spi_data *tspi,
struct spi_transfer *t)
{
unsigned remain_len = t->len - tspi->cur_pos;
unsigned max_word;
unsigned bits_per_word = t->bits_per_word;
unsigned max_len;
unsigned total_fifo_words;
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;
}
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 + 3) / 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_spi_fill_tx_fifo_from_client_txbuf(
struct tegra_spi_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_spi_readl(tspi, SPI_FIFO_STATUS);
tx_empty_count = SPI_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_spi_writel(tspi, x, SPI_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_spi_writel(tspi, x, SPI_TX_FIFO);
}
}
tspi->cur_tx_pos += written_words * tspi->bytes_per_word;
return written_words;
}
static unsigned int tegra_spi_read_rx_fifo_to_client_rxbuf(
struct tegra_spi_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_spi_readl(tspi, SPI_FIFO_STATUS);
rx_full_count = SPI_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_spi_readl(tspi, SPI_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 {
u32 rx_mask = ((u32)1 << t->bits_per_word) - 1;
for (count = 0; count < rx_full_count; count++) {
u32 x = tegra_spi_readl(tspi, SPI_RX_FIFO) & rx_mask;
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_spi_copy_client_txbuf_to_spi_txbuf(
struct tegra_spi_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_spi_copy_spi_rxbuf_to_client_rxbuf(
struct tegra_spi_data *tspi, struct spi_transfer *t)
{
/* 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) {
unsigned 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_spi_dma_complete(void *args)
{
struct completion *dma_complete = args;
complete(dma_complete);
}
static int tegra_spi_start_tx_dma(struct tegra_spi_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_spi_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_spi_start_rx_dma(struct tegra_spi_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_spi_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_spi_start_dma_based_transfer(
struct tegra_spi_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_spi_readl(tspi, SPI_FIFO_STATUS);
if ((status & SPI_FIFO_EMPTY) != SPI_FIFO_EMPTY) {
dev_err(tspi->dev, "Rx/Tx fifo are not empty status 0x%08x\n",
(unsigned)status);
return -EIO;
}
val = SPI_DMA_BLK_SET(tspi->curr_dma_words - 1);
tegra_spi_writel(tspi, val, SPI_DMA_BLK);
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 |= SPI_TX_TRIG_1 | SPI_RX_TRIG_1;
else if (((len) >> 4) & 0x1)
val |= SPI_TX_TRIG_4 | SPI_RX_TRIG_4;
else
val |= SPI_TX_TRIG_8 | SPI_RX_TRIG_8;
if (tspi->cur_direction & DATA_DIR_TX)
val |= SPI_IE_TX;
if (tspi->cur_direction & DATA_DIR_RX)
val |= SPI_IE_RX;
tegra_spi_writel(tspi, val, SPI_DMA_CTL);
tspi->dma_control_reg = val;
if (tspi->cur_direction & DATA_DIR_TX) {
tegra_spi_copy_client_txbuf_to_spi_txbuf(tspi, t);
ret = tegra_spi_start_tx_dma(tspi, len);
if (ret < 0) {
dev_err(tspi->dev,
"Starting tx dma failed, err %d\n", ret);
return ret;
}
}
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_spi_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;
tspi->dma_control_reg = val;
val |= SPI_DMA_EN;
tegra_spi_writel(tspi, val, SPI_DMA_CTL);
return ret;
}
static int tegra_spi_start_cpu_based_transfer(
struct tegra_spi_data *tspi, struct spi_transfer *t)
{
u32 val;
unsigned cur_words;
if (tspi->cur_direction & DATA_DIR_TX)
cur_words = tegra_spi_fill_tx_fifo_from_client_txbuf(tspi, t);
else
cur_words = tspi->curr_dma_words;
val = SPI_DMA_BLK_SET(cur_words - 1);
tegra_spi_writel(tspi, val, SPI_DMA_BLK);
val = 0;
if (tspi->cur_direction & DATA_DIR_TX)
val |= SPI_IE_TX;
if (tspi->cur_direction & DATA_DIR_RX)
val |= SPI_IE_RX;
tegra_spi_writel(tspi, val, SPI_DMA_CTL);
tspi->dma_control_reg = val;
tspi->is_curr_dma_xfer = false;
val |= SPI_DMA_EN;
tegra_spi_writel(tspi, val, SPI_DMA_CTL);
return 0;
}
static int tegra_spi_init_dma_param(struct tegra_spi_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 + SPI_RX_FIFO;
dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
dma_sconfig.src_maxburst = 0;
} else {
dma_sconfig.dst_addr = tspi->phys + SPI_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_spi_deinit_dma_param(struct tegra_spi_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 u32 tegra_spi_setup_transfer_one(struct spi_device *spi,
struct spi_transfer *t, bool is_first_of_msg)
{
struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
u32 speed = t->speed_hz;
u8 bits_per_word = t->bits_per_word;
u32 command1;
int req_mode;
if (speed != tspi->cur_speed) {
clk_set_rate(tspi->clk, speed);
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;
if (is_first_of_msg) {
tegra_spi_clear_status(tspi);
command1 = tspi->def_command1_reg;
command1 |= SPI_BIT_LENGTH(bits_per_word - 1);
command1 &= ~SPI_CONTROL_MODE_MASK;
req_mode = spi->mode & 0x3;
if (req_mode == SPI_MODE_0)
command1 |= SPI_CONTROL_MODE_0;
else if (req_mode == SPI_MODE_1)
command1 |= SPI_CONTROL_MODE_1;
else if (req_mode == SPI_MODE_2)
command1 |= SPI_CONTROL_MODE_2;
else if (req_mode == SPI_MODE_3)
command1 |= SPI_CONTROL_MODE_3;
if (tspi->cs_control) {
if (tspi->cs_control != spi)
tegra_spi_writel(tspi, command1, SPI_COMMAND1);
tspi->cs_control = NULL;
} else
tegra_spi_writel(tspi, command1, SPI_COMMAND1);
command1 |= SPI_CS_SW_HW;
if (spi->mode & SPI_CS_HIGH)
command1 |= SPI_CS_SS_VAL;
else
command1 &= ~SPI_CS_SS_VAL;
tegra_spi_writel(tspi, 0, SPI_COMMAND2);
} else {
command1 = tspi->command1_reg;
command1 &= ~SPI_BIT_LENGTH(~0);
command1 |= SPI_BIT_LENGTH(bits_per_word - 1);
}
return command1;
}
static int tegra_spi_start_transfer_one(struct spi_device *spi,
struct spi_transfer *t, u32 command1)
{
struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
unsigned total_fifo_words;
int ret;
total_fifo_words = tegra_spi_calculate_curr_xfer_param(spi, tspi, t);
if (tspi->is_packed)
command1 |= SPI_PACKED;
command1 &= ~(SPI_CS_SEL_MASK | SPI_TX_EN | SPI_RX_EN);
tspi->cur_direction = 0;
if (t->rx_buf) {
command1 |= SPI_RX_EN;
tspi->cur_direction |= DATA_DIR_RX;
}
if (t->tx_buf) {
command1 |= SPI_TX_EN;
tspi->cur_direction |= DATA_DIR_TX;
}
command1 |= SPI_CS_SEL(spi->chip_select);
tegra_spi_writel(tspi, command1, SPI_COMMAND1);
tspi->command1_reg = command1;
dev_dbg(tspi->dev, "The def 0x%x and written 0x%x\n",
tspi->def_command1_reg, (unsigned)command1);
if (total_fifo_words > SPI_FIFO_DEPTH)
ret = tegra_spi_start_dma_based_transfer(tspi, t);
else
ret = tegra_spi_start_cpu_based_transfer(tspi, t);
return ret;
}
static int tegra_spi_setup(struct spi_device *spi)
{
struct tegra_spi_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_command1_reg;
if (spi->mode & SPI_CS_HIGH)
val &= ~SPI_CS_POL_INACTIVE(spi->chip_select);
else
val |= SPI_CS_POL_INACTIVE(spi->chip_select);
tspi->def_command1_reg = val;
tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
spin_unlock_irqrestore(&tspi->lock, flags);
pm_runtime_put(tspi->dev);
return 0;
}
static void tegra_spi_transfer_delay(int delay)
{
if (!delay)
return;
if (delay >= 1000)
mdelay(delay / 1000);
udelay(delay % 1000);
}
static int tegra_spi_transfer_one_message(struct spi_master *master,
struct spi_message *msg)
{
bool is_first_msg = true;
struct tegra_spi_data *tspi = spi_master_get_devdata(master);
struct spi_transfer *xfer;
struct spi_device *spi = msg->spi;
int ret;
bool skip = false;
msg->status = 0;
msg->actual_length = 0;
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
u32 cmd1;
reinit_completion(&tspi->xfer_completion);
cmd1 = tegra_spi_setup_transfer_one(spi, xfer, is_first_msg);
if (!xfer->len) {
ret = 0;
skip = true;
goto complete_xfer;
}
ret = tegra_spi_start_transfer_one(spi, xfer, cmd1);
if (ret < 0) {
dev_err(tspi->dev,
"spi can not start transfer, err %d\n", ret);
goto complete_xfer;
}
is_first_msg = false;
ret = wait_for_completion_timeout(&tspi->xfer_completion,
SPI_DMA_TIMEOUT);
if (WARN_ON(ret == 0)) {
dev_err(tspi->dev,
"spi trasfer timeout, err %d\n", ret);
ret = -EIO;
goto complete_xfer;
}
if (tspi->tx_status || tspi->rx_status) {
dev_err(tspi->dev, "Error in Transfer\n");
ret = -EIO;
goto complete_xfer;
}
msg->actual_length += xfer->len;
complete_xfer:
if (ret < 0 || skip) {
tegra_spi_writel(tspi, tspi->def_command1_reg,
SPI_COMMAND1);
tegra_spi_transfer_delay(xfer->delay_usecs);
goto exit;
} else if (list_is_last(&xfer->transfer_list,
&msg->transfers)) {
if (xfer->cs_change)
tspi->cs_control = spi;
else {
tegra_spi_writel(tspi, tspi->def_command1_reg,
SPI_COMMAND1);
tegra_spi_transfer_delay(xfer->delay_usecs);
}
} else if (xfer->cs_change) {
tegra_spi_writel(tspi, tspi->def_command1_reg,
SPI_COMMAND1);
tegra_spi_transfer_delay(xfer->delay_usecs);
}
}
ret = 0;
exit:
msg->status = ret;
spi_finalize_current_message(master);
return ret;
}
static irqreturn_t handle_cpu_based_xfer(struct tegra_spi_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) {
dev_err(tspi->dev, "CpuXfer ERROR bit set 0x%x\n",
tspi->status_reg);
dev_err(tspi->dev, "CpuXfer 0x%08x:0x%08x\n",
tspi->command1_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_spi_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_spi_calculate_curr_xfer_param(tspi->cur_spi, tspi, t);
tegra_spi_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_spi_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, SPI_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, SPI_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\n",
tspi->command1_reg, tspi->dma_control_reg);
reset_control_assert(tspi->rst);
udelay(2);
reset_control_deassert(tspi->rst);
complete(&tspi->xfer_completion);
spin_unlock_irqrestore(&tspi->lock, flags);
return IRQ_HANDLED;
}
if (tspi->cur_direction & DATA_DIR_RX)
tegra_spi_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_spi_calculate_curr_xfer_param(tspi->cur_spi,
tspi, t);
if (total_fifo_words > SPI_FIFO_DEPTH)
err = tegra_spi_start_dma_based_transfer(tspi, t);
else
err = tegra_spi_start_cpu_based_transfer(tspi, t);
exit:
spin_unlock_irqrestore(&tspi->lock, flags);
return IRQ_HANDLED;
}
static irqreturn_t tegra_spi_isr_thread(int irq, void *context_data)
{
struct tegra_spi_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_spi_isr(int irq, void *context_data)
{
struct tegra_spi_data *tspi = context_data;
tspi->status_reg = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
if (tspi->cur_direction & DATA_DIR_TX)
tspi->tx_status = tspi->status_reg &
(SPI_TX_FIFO_UNF | SPI_TX_FIFO_OVF);
if (tspi->cur_direction & DATA_DIR_RX)
tspi->rx_status = tspi->status_reg &
(SPI_RX_FIFO_OVF | SPI_RX_FIFO_UNF);
tegra_spi_clear_status(tspi);
return IRQ_WAKE_THREAD;
}
static const struct of_device_id tegra_spi_of_match[] = {
{ .compatible = "nvidia,tegra114-spi", },
{}
};
MODULE_DEVICE_TABLE(of, tegra_spi_of_match);
static int tegra_spi_probe(struct platform_device *pdev)
{
struct spi_master *master;
struct tegra_spi_data *tspi;
struct resource *r;
int ret, spi_irq;
master = spi_alloc_master(&pdev->dev, sizeof(*tspi));
if (!master) {
dev_err(&pdev->dev, "master allocation failed\n");
return -ENOMEM;
}
platform_set_drvdata(pdev, master);
tspi = spi_master_get_devdata(master);
if (of_property_read_u32(pdev->dev.of_node, "spi-max-frequency",
&master->max_speed_hz))
master->max_speed_hz = 25000000; /* 25MHz */
/* the spi->mode bits understood by this driver: */
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
master->setup = tegra_spi_setup;
master->transfer_one_message = tegra_spi_transfer_one_message;
master->num_chipselect = MAX_CHIP_SELECT;
master->auto_runtime_pm = true;
tspi->master = master;
tspi->dev = &pdev->dev;
spin_lock_init(&tspi->lock);
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
tspi->base = devm_ioremap_resource(&pdev->dev, r);
if (IS_ERR(tspi->base)) {
ret = PTR_ERR(tspi->base);
goto exit_free_master;
}
tspi->phys = r->start;
spi_irq = platform_get_irq(pdev, 0);
tspi->irq = spi_irq;
ret = request_threaded_irq(tspi->irq, tegra_spi_isr,
tegra_spi_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, "spi");
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 = SPI_FIFO_DEPTH << 2;
tspi->dma_buf_size = DEFAULT_SPI_DMA_BUF_LEN;
ret = tegra_spi_init_dma_param(tspi, true);
if (ret < 0)
goto exit_free_irq;
ret = tegra_spi_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_spi_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_command1_reg = SPI_M_S;
tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
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_spi_runtime_suspend(&pdev->dev);
tegra_spi_deinit_dma_param(tspi, false);
exit_rx_dma_free:
tegra_spi_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_spi_remove(struct platform_device *pdev)
{
struct spi_master *master = platform_get_drvdata(pdev);
struct tegra_spi_data *tspi = spi_master_get_devdata(master);
free_irq(tspi->irq, tspi);
if (tspi->tx_dma_chan)
tegra_spi_deinit_dma_param(tspi, false);
if (tspi->rx_dma_chan)
tegra_spi_deinit_dma_param(tspi, true);
pm_runtime_disable(&pdev->dev);
if (!pm_runtime_status_suspended(&pdev->dev))
tegra_spi_runtime_suspend(&pdev->dev);
return 0;
}
#ifdef [31mCONFIG_PM_SLEEP[0m
static int tegra_spi_suspend(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
return spi_master_suspend(master);
}
static int tegra_spi_resume(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
struct tegra_spi_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_spi_writel(tspi, tspi->command1_reg, SPI_COMMAND1);
pm_runtime_put(dev);
return spi_master_resume(master);
}
#endif
static int tegra_spi_runtime_suspend(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
struct tegra_spi_data *tspi = spi_master_get_devdata(master);
/* Flush all write which are in PPSB queue by reading back */
tegra_spi_readl(tspi, SPI_COMMAND1);
clk_disable_unprepare(tspi->clk);
return 0;
}
static int tegra_spi_runtime_resume(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
struct tegra_spi_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 tegra_spi_pm_ops = {
SET_RUNTIME_PM_OPS(tegra_spi_runtime_suspend,
tegra_spi_runtime_resume, NULL)
SET_SYSTEM_SLEEP_PM_OPS(tegra_spi_suspend, tegra_spi_resume)
};
static struct platform_driver tegra_spi_driver = {
.driver = {
.name = "spi-tegra114",
.pm = &tegra_spi_pm_ops,
.of_match_table = tegra_spi_of_match,
},
.probe = tegra_spi_probe,
.remove = tegra_spi_remove,
};
module_platform_driver(tegra_spi_driver);
MODULE_ALIAS("platform:spi-tegra114");
MODULE_DESCRIPTION("NVIDIA Tegra114 SPI Controller Driver");
MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
MODULE_LICENSE("GPL v2");