diff options
Diffstat (limited to 'drivers/spi/spi-tegra20-slink.c')
| -rw-r--r-- | drivers/spi/spi-tegra20-slink.c | 1232 |
1 files changed, 1232 insertions, 0 deletions
diff --git a/drivers/spi/spi-tegra20-slink.c b/drivers/spi/spi-tegra20-slink.c new file mode 100644 index 000000000..24cab56ec --- /dev/null +++ b/drivers/spi/spi-tegra20-slink.c @@ -0,0 +1,1232 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * SPI driver for Nvidia's Tegra20/Tegra30 SLINK Controller. + * + * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved. + */ + +#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_opp.h> +#include <linux/pm_runtime.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/reset.h> +#include <linux/spi/spi.h> + +#include <soc/tegra/common.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 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 = true; + tspi->words_per_32bit = 32/bits_per_word; + } else { + tspi->is_packed = false; + 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_chan(tspi->dev, dma_to_memory ? "rx" : "tx"); + if (IS_ERR(dma_chan)) + return dev_err_probe(tspi->dev, PTR_ERR(dma_chan), + "Dma channel is not available\n"); + + 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) { + dev_pm_opp_set_rate(tspi->dev, 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); + + 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; + } + + /* + * Writing to the command2 register bevore the command register prevents + * a spike in chip_select line 0. This selects the chip_select line + * before changing the chip_select value. + */ + tegra_slink_writel(tspi, command2, SLINK_COMMAND2); + tspi->command2_reg = command2; + + tegra_slink_writel(tspi, command, SLINK_COMMAND); + tspi->command_reg = command; + + 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_resume_and_get(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 transfer 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; + + cdata = of_device_get_match_data(&pdev->dev); + + 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; + } + + /* disabled clock may cause interrupt storm upon request */ + tspi->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(tspi->clk)) { + ret = PTR_ERR(tspi->clk); + dev_err(&pdev->dev, "Can not get clock %d\n", ret); + goto exit_free_master; + } + + tspi->rst = devm_reset_control_get_exclusive(&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_master; + } + + ret = devm_tegra_core_dev_init_opp_table_common(&pdev->dev); + if (ret) + goto exit_free_master; + + 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_master; + 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); + ret = pm_runtime_resume_and_get(&pdev->dev); + if (ret) { + dev_err(&pdev->dev, "pm runtime get failed, e = %d\n", ret); + goto exit_pm_disable; + } + + reset_control_assert(tspi->rst); + udelay(2); + reset_control_deassert(tspi->rst); + + spi_irq = platform_get_irq(pdev, 0); + if (spi_irq < 0) + return spi_irq; + 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_pm_put; + } + + 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); + + master->dev.of_node = pdev->dev.of_node; + ret = spi_register_master(master); + if (ret < 0) { + dev_err(&pdev->dev, "can not register to master err %d\n", ret); + goto exit_free_irq; + } + + pm_runtime_put(&pdev->dev); + + return ret; + +exit_free_irq: + free_irq(spi_irq, tspi); +exit_pm_put: + pm_runtime_put(&pdev->dev); +exit_pm_disable: + pm_runtime_force_suspend(&pdev->dev); + + tegra_slink_deinit_dma_param(tspi, false); +exit_rx_dma_free: + tegra_slink_deinit_dma_param(tspi, true); +exit_free_master: + spi_master_put(master); + return ret; +} + +static int tegra_slink_remove(struct platform_device *pdev) +{ + struct spi_master *master = spi_master_get(platform_get_drvdata(pdev)); + struct tegra_slink_data *tspi = spi_master_get_devdata(master); + + spi_unregister_master(master); + + free_irq(tspi->irq, tspi); + + pm_runtime_force_suspend(&pdev->dev); + + if (tspi->tx_dma_chan) + tegra_slink_deinit_dma_param(tspi, false); + + if (tspi->rx_dma_chan) + tegra_slink_deinit_dma_param(tspi, true); + + spi_master_put(master); + 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_resume_and_get(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 __maybe_unused 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 __maybe_unused 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"); |