// 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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) { 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); 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_get_sync(tspi->dev); if (ret < 0) { pm_runtime_put_noidle(tspi->dev); 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; } 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_disable(&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_disable(&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_get_sync(dev); if (ret < 0) { pm_runtime_put_noidle(dev); 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 "); MODULE_LICENSE("GPL v2");