diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/spi/spi-geni-qcom.c | 1110 |
1 files changed, 1110 insertions, 0 deletions
diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c new file mode 100644 index 000000000..7b76dcd11 --- /dev/null +++ b/drivers/spi/spi-geni-qcom.c @@ -0,0 +1,1110 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2017-2018, The Linux foundation. All rights reserved. + +#include <linux/clk.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/dma/qcom-gpi-dma.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/log2.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/pm_opp.h> +#include <linux/pm_runtime.h> +#include <linux/qcom-geni-se.h> +#include <linux/spi/spi.h> +#include <linux/spinlock.h> + +/* SPI SE specific registers and respective register fields */ +#define SE_SPI_CPHA 0x224 +#define CPHA BIT(0) + +#define SE_SPI_LOOPBACK 0x22c +#define LOOPBACK_ENABLE 0x1 +#define NORMAL_MODE 0x0 +#define LOOPBACK_MSK GENMASK(1, 0) + +#define SE_SPI_CPOL 0x230 +#define CPOL BIT(2) + +#define SE_SPI_DEMUX_OUTPUT_INV 0x24c +#define CS_DEMUX_OUTPUT_INV_MSK GENMASK(3, 0) + +#define SE_SPI_DEMUX_SEL 0x250 +#define CS_DEMUX_OUTPUT_SEL GENMASK(3, 0) + +#define SE_SPI_TRANS_CFG 0x25c +#define CS_TOGGLE BIT(1) + +#define SE_SPI_WORD_LEN 0x268 +#define WORD_LEN_MSK GENMASK(9, 0) +#define MIN_WORD_LEN 4 + +#define SE_SPI_TX_TRANS_LEN 0x26c +#define SE_SPI_RX_TRANS_LEN 0x270 +#define TRANS_LEN_MSK GENMASK(23, 0) + +#define SE_SPI_PRE_POST_CMD_DLY 0x274 + +#define SE_SPI_DELAY_COUNTERS 0x278 +#define SPI_INTER_WORDS_DELAY_MSK GENMASK(9, 0) +#define SPI_CS_CLK_DELAY_MSK GENMASK(19, 10) +#define SPI_CS_CLK_DELAY_SHFT 10 + +/* M_CMD OP codes for SPI */ +#define SPI_TX_ONLY 1 +#define SPI_RX_ONLY 2 +#define SPI_TX_RX 7 +#define SPI_CS_ASSERT 8 +#define SPI_CS_DEASSERT 9 +#define SPI_SCK_ONLY 10 +/* M_CMD params for SPI */ +#define SPI_PRE_CMD_DELAY BIT(0) +#define TIMESTAMP_BEFORE BIT(1) +#define FRAGMENTATION BIT(2) +#define TIMESTAMP_AFTER BIT(3) +#define POST_CMD_DELAY BIT(4) + +#define GSI_LOOPBACK_EN BIT(0) +#define GSI_CS_TOGGLE BIT(3) +#define GSI_CPHA BIT(4) +#define GSI_CPOL BIT(5) + +struct spi_geni_master { + struct geni_se se; + struct device *dev; + u32 tx_fifo_depth; + u32 fifo_width_bits; + u32 tx_wm; + u32 last_mode; + unsigned long cur_speed_hz; + unsigned long cur_sclk_hz; + unsigned int cur_bits_per_word; + unsigned int tx_rem_bytes; + unsigned int rx_rem_bytes; + const struct spi_transfer *cur_xfer; + struct completion cs_done; + struct completion cancel_done; + struct completion abort_done; + unsigned int oversampling; + spinlock_t lock; + int irq; + bool cs_flag; + bool abort_failed; + struct dma_chan *tx; + struct dma_chan *rx; + int cur_xfer_mode; +}; + +static int get_spi_clk_cfg(unsigned int speed_hz, + struct spi_geni_master *mas, + unsigned int *clk_idx, + unsigned int *clk_div) +{ + unsigned long sclk_freq; + unsigned int actual_hz; + int ret; + + ret = geni_se_clk_freq_match(&mas->se, + speed_hz * mas->oversampling, + clk_idx, &sclk_freq, false); + if (ret) { + dev_err(mas->dev, "Failed(%d) to find src clk for %dHz\n", + ret, speed_hz); + return ret; + } + + *clk_div = DIV_ROUND_UP(sclk_freq, mas->oversampling * speed_hz); + actual_hz = sclk_freq / (mas->oversampling * *clk_div); + + dev_dbg(mas->dev, "req %u=>%u sclk %lu, idx %d, div %d\n", speed_hz, + actual_hz, sclk_freq, *clk_idx, *clk_div); + ret = dev_pm_opp_set_rate(mas->dev, sclk_freq); + if (ret) + dev_err(mas->dev, "dev_pm_opp_set_rate failed %d\n", ret); + else + mas->cur_sclk_hz = sclk_freq; + + return ret; +} + +static void handle_fifo_timeout(struct spi_master *spi, + struct spi_message *msg) +{ + struct spi_geni_master *mas = spi_master_get_devdata(spi); + unsigned long time_left; + struct geni_se *se = &mas->se; + + spin_lock_irq(&mas->lock); + reinit_completion(&mas->cancel_done); + writel(0, se->base + SE_GENI_TX_WATERMARK_REG); + mas->cur_xfer = NULL; + geni_se_cancel_m_cmd(se); + spin_unlock_irq(&mas->lock); + + time_left = wait_for_completion_timeout(&mas->cancel_done, HZ); + if (time_left) + return; + + spin_lock_irq(&mas->lock); + reinit_completion(&mas->abort_done); + geni_se_abort_m_cmd(se); + spin_unlock_irq(&mas->lock); + + time_left = wait_for_completion_timeout(&mas->abort_done, HZ); + if (!time_left) { + dev_err(mas->dev, "Failed to cancel/abort m_cmd\n"); + + /* + * No need for a lock since SPI core has a lock and we never + * access this from an interrupt. + */ + mas->abort_failed = true; + } +} + +static void handle_gpi_timeout(struct spi_master *spi, struct spi_message *msg) +{ + struct spi_geni_master *mas = spi_master_get_devdata(spi); + + dmaengine_terminate_sync(mas->tx); + dmaengine_terminate_sync(mas->rx); +} + +static void spi_geni_handle_err(struct spi_master *spi, struct spi_message *msg) +{ + struct spi_geni_master *mas = spi_master_get_devdata(spi); + + switch (mas->cur_xfer_mode) { + case GENI_SE_FIFO: + handle_fifo_timeout(spi, msg); + break; + case GENI_GPI_DMA: + handle_gpi_timeout(spi, msg); + break; + default: + dev_err(mas->dev, "Abort on Mode:%d not supported", mas->cur_xfer_mode); + } +} + +static bool spi_geni_is_abort_still_pending(struct spi_geni_master *mas) +{ + struct geni_se *se = &mas->se; + u32 m_irq, m_irq_en; + + if (!mas->abort_failed) + return false; + + /* + * The only known case where a transfer times out and then a cancel + * times out then an abort times out is if something is blocking our + * interrupt handler from running. Avoid starting any new transfers + * until that sorts itself out. + */ + spin_lock_irq(&mas->lock); + m_irq = readl(se->base + SE_GENI_M_IRQ_STATUS); + m_irq_en = readl(se->base + SE_GENI_M_IRQ_EN); + spin_unlock_irq(&mas->lock); + + if (m_irq & m_irq_en) { + dev_err(mas->dev, "Interrupts pending after abort: %#010x\n", + m_irq & m_irq_en); + return true; + } + + /* + * If we're here the problem resolved itself so no need to check more + * on future transfers. + */ + mas->abort_failed = false; + + return false; +} + +static void spi_geni_set_cs(struct spi_device *slv, bool set_flag) +{ + struct spi_geni_master *mas = spi_master_get_devdata(slv->master); + struct spi_master *spi = dev_get_drvdata(mas->dev); + struct geni_se *se = &mas->se; + unsigned long time_left; + + if (!(slv->mode & SPI_CS_HIGH)) + set_flag = !set_flag; + + if (set_flag == mas->cs_flag) + return; + + pm_runtime_get_sync(mas->dev); + + if (spi_geni_is_abort_still_pending(mas)) { + dev_err(mas->dev, "Can't set chip select\n"); + goto exit; + } + + spin_lock_irq(&mas->lock); + if (mas->cur_xfer) { + dev_err(mas->dev, "Can't set CS when prev xfer running\n"); + spin_unlock_irq(&mas->lock); + goto exit; + } + + mas->cs_flag = set_flag; + reinit_completion(&mas->cs_done); + if (set_flag) + geni_se_setup_m_cmd(se, SPI_CS_ASSERT, 0); + else + geni_se_setup_m_cmd(se, SPI_CS_DEASSERT, 0); + spin_unlock_irq(&mas->lock); + + time_left = wait_for_completion_timeout(&mas->cs_done, HZ); + if (!time_left) { + dev_warn(mas->dev, "Timeout setting chip select\n"); + handle_fifo_timeout(spi, NULL); + } + +exit: + pm_runtime_put(mas->dev); +} + +static void spi_setup_word_len(struct spi_geni_master *mas, u16 mode, + unsigned int bits_per_word) +{ + unsigned int pack_words; + bool msb_first = (mode & SPI_LSB_FIRST) ? false : true; + struct geni_se *se = &mas->se; + u32 word_len; + + /* + * If bits_per_word isn't a byte aligned value, set the packing to be + * 1 SPI word per FIFO word. + */ + if (!(mas->fifo_width_bits % bits_per_word)) + pack_words = mas->fifo_width_bits / bits_per_word; + else + pack_words = 1; + geni_se_config_packing(&mas->se, bits_per_word, pack_words, msb_first, + true, true); + word_len = (bits_per_word - MIN_WORD_LEN) & WORD_LEN_MSK; + writel(word_len, se->base + SE_SPI_WORD_LEN); +} + +static int geni_spi_set_clock_and_bw(struct spi_geni_master *mas, + unsigned long clk_hz) +{ + u32 clk_sel, m_clk_cfg, idx, div; + struct geni_se *se = &mas->se; + int ret; + + if (clk_hz == mas->cur_speed_hz) + return 0; + + ret = get_spi_clk_cfg(clk_hz, mas, &idx, &div); + if (ret) { + dev_err(mas->dev, "Err setting clk to %lu: %d\n", clk_hz, ret); + return ret; + } + + /* + * SPI core clock gets configured with the requested frequency + * or the frequency closer to the requested frequency. + * For that reason requested frequency is stored in the + * cur_speed_hz and referred in the consecutive transfer instead + * of calling clk_get_rate() API. + */ + mas->cur_speed_hz = clk_hz; + + clk_sel = idx & CLK_SEL_MSK; + m_clk_cfg = (div << CLK_DIV_SHFT) | SER_CLK_EN; + writel(clk_sel, se->base + SE_GENI_CLK_SEL); + writel(m_clk_cfg, se->base + GENI_SER_M_CLK_CFG); + + /* Set BW quota for CPU as driver supports FIFO mode only. */ + se->icc_paths[CPU_TO_GENI].avg_bw = Bps_to_icc(mas->cur_speed_hz); + ret = geni_icc_set_bw(se); + if (ret) + return ret; + + return 0; +} + +static int setup_fifo_params(struct spi_device *spi_slv, + struct spi_master *spi) +{ + struct spi_geni_master *mas = spi_master_get_devdata(spi); + struct geni_se *se = &mas->se; + u32 loopback_cfg = 0, cpol = 0, cpha = 0, demux_output_inv = 0; + u32 demux_sel; + + if (mas->last_mode != spi_slv->mode) { + if (spi_slv->mode & SPI_LOOP) + loopback_cfg = LOOPBACK_ENABLE; + + if (spi_slv->mode & SPI_CPOL) + cpol = CPOL; + + if (spi_slv->mode & SPI_CPHA) + cpha = CPHA; + + if (spi_slv->mode & SPI_CS_HIGH) + demux_output_inv = BIT(spi_slv->chip_select); + + demux_sel = spi_slv->chip_select; + mas->cur_bits_per_word = spi_slv->bits_per_word; + + spi_setup_word_len(mas, spi_slv->mode, spi_slv->bits_per_word); + writel(loopback_cfg, se->base + SE_SPI_LOOPBACK); + writel(demux_sel, se->base + SE_SPI_DEMUX_SEL); + writel(cpha, se->base + SE_SPI_CPHA); + writel(cpol, se->base + SE_SPI_CPOL); + writel(demux_output_inv, se->base + SE_SPI_DEMUX_OUTPUT_INV); + + mas->last_mode = spi_slv->mode; + } + + return geni_spi_set_clock_and_bw(mas, spi_slv->max_speed_hz); +} + +static void +spi_gsi_callback_result(void *cb, const struct dmaengine_result *result) +{ + struct spi_master *spi = cb; + + spi->cur_msg->status = -EIO; + if (result->result != DMA_TRANS_NOERROR) { + dev_err(&spi->dev, "DMA txn failed: %d\n", result->result); + spi_finalize_current_transfer(spi); + return; + } + + if (!result->residue) { + spi->cur_msg->status = 0; + dev_dbg(&spi->dev, "DMA txn completed\n"); + } else { + dev_err(&spi->dev, "DMA xfer has pending: %d\n", result->residue); + } + + spi_finalize_current_transfer(spi); +} + +static int setup_gsi_xfer(struct spi_transfer *xfer, struct spi_geni_master *mas, + struct spi_device *spi_slv, struct spi_master *spi) +{ + unsigned long flags = DMA_PREP_INTERRUPT | DMA_CTRL_ACK; + struct dma_slave_config config = {}; + struct gpi_spi_config peripheral = {}; + struct dma_async_tx_descriptor *tx_desc, *rx_desc; + int ret; + + config.peripheral_config = &peripheral; + config.peripheral_size = sizeof(peripheral); + peripheral.set_config = true; + + if (xfer->bits_per_word != mas->cur_bits_per_word || + xfer->speed_hz != mas->cur_speed_hz) { + mas->cur_bits_per_word = xfer->bits_per_word; + mas->cur_speed_hz = xfer->speed_hz; + } + + if (xfer->tx_buf && xfer->rx_buf) { + peripheral.cmd = SPI_DUPLEX; + } else if (xfer->tx_buf) { + peripheral.cmd = SPI_TX; + peripheral.rx_len = 0; + } else if (xfer->rx_buf) { + peripheral.cmd = SPI_RX; + if (!(mas->cur_bits_per_word % MIN_WORD_LEN)) { + peripheral.rx_len = ((xfer->len << 3) / mas->cur_bits_per_word); + } else { + int bytes_per_word = (mas->cur_bits_per_word / BITS_PER_BYTE) + 1; + + peripheral.rx_len = (xfer->len / bytes_per_word); + } + } + + peripheral.loopback_en = !!(spi_slv->mode & SPI_LOOP); + peripheral.clock_pol_high = !!(spi_slv->mode & SPI_CPOL); + peripheral.data_pol_high = !!(spi_slv->mode & SPI_CPHA); + peripheral.cs = spi_slv->chip_select; + peripheral.pack_en = true; + peripheral.word_len = xfer->bits_per_word - MIN_WORD_LEN; + + ret = get_spi_clk_cfg(mas->cur_speed_hz, mas, + &peripheral.clk_src, &peripheral.clk_div); + if (ret) { + dev_err(mas->dev, "Err in get_spi_clk_cfg() :%d\n", ret); + return ret; + } + + if (!xfer->cs_change) { + if (!list_is_last(&xfer->transfer_list, &spi->cur_msg->transfers)) + peripheral.fragmentation = FRAGMENTATION; + } + + if (peripheral.cmd & SPI_RX) { + dmaengine_slave_config(mas->rx, &config); + rx_desc = dmaengine_prep_slave_sg(mas->rx, xfer->rx_sg.sgl, xfer->rx_sg.nents, + DMA_DEV_TO_MEM, flags); + if (!rx_desc) { + dev_err(mas->dev, "Err setting up rx desc\n"); + return -EIO; + } + } + + /* + * Prepare the TX always, even for RX or tx_buf being null, we would + * need TX to be prepared per GSI spec + */ + dmaengine_slave_config(mas->tx, &config); + tx_desc = dmaengine_prep_slave_sg(mas->tx, xfer->tx_sg.sgl, xfer->tx_sg.nents, + DMA_MEM_TO_DEV, flags); + if (!tx_desc) { + dev_err(mas->dev, "Err setting up tx desc\n"); + return -EIO; + } + + tx_desc->callback_result = spi_gsi_callback_result; + tx_desc->callback_param = spi; + + if (peripheral.cmd & SPI_RX) + dmaengine_submit(rx_desc); + dmaengine_submit(tx_desc); + + if (peripheral.cmd & SPI_RX) + dma_async_issue_pending(mas->rx); + + dma_async_issue_pending(mas->tx); + return 1; +} + +static bool geni_can_dma(struct spi_controller *ctlr, + struct spi_device *slv, struct spi_transfer *xfer) +{ + struct spi_geni_master *mas = spi_master_get_devdata(slv->master); + + /* check if dma is supported */ + return mas->cur_xfer_mode != GENI_SE_FIFO; +} + +static int spi_geni_prepare_message(struct spi_master *spi, + struct spi_message *spi_msg) +{ + struct spi_geni_master *mas = spi_master_get_devdata(spi); + int ret; + + switch (mas->cur_xfer_mode) { + case GENI_SE_FIFO: + if (spi_geni_is_abort_still_pending(mas)) + return -EBUSY; + ret = setup_fifo_params(spi_msg->spi, spi); + if (ret) + dev_err(mas->dev, "Couldn't select mode %d\n", ret); + return ret; + + case GENI_GPI_DMA: + /* nothing to do for GPI DMA */ + return 0; + } + + dev_err(mas->dev, "Mode not supported %d", mas->cur_xfer_mode); + return -EINVAL; +} + +static int spi_geni_grab_gpi_chan(struct spi_geni_master *mas) +{ + int ret; + + mas->tx = dma_request_chan(mas->dev, "tx"); + if (IS_ERR(mas->tx)) { + ret = dev_err_probe(mas->dev, PTR_ERR(mas->tx), + "Failed to get tx DMA ch\n"); + goto err_tx; + } + + mas->rx = dma_request_chan(mas->dev, "rx"); + if (IS_ERR(mas->rx)) { + ret = dev_err_probe(mas->dev, PTR_ERR(mas->rx), + "Failed to get rx DMA ch\n"); + goto err_rx; + } + + return 0; + +err_rx: + mas->rx = NULL; + dma_release_channel(mas->tx); +err_tx: + mas->tx = NULL; + return ret; +} + +static void spi_geni_release_dma_chan(struct spi_geni_master *mas) +{ + if (mas->rx) { + dma_release_channel(mas->rx); + mas->rx = NULL; + } + + if (mas->tx) { + dma_release_channel(mas->tx); + mas->tx = NULL; + } +} + +static int spi_geni_init(struct spi_geni_master *mas) +{ + struct geni_se *se = &mas->se; + unsigned int proto, major, minor, ver; + u32 spi_tx_cfg, fifo_disable; + int ret = -ENXIO; + + pm_runtime_get_sync(mas->dev); + + proto = geni_se_read_proto(se); + if (proto != GENI_SE_SPI) { + dev_err(mas->dev, "Invalid proto %d\n", proto); + goto out_pm; + } + mas->tx_fifo_depth = geni_se_get_tx_fifo_depth(se); + + /* Width of Tx and Rx FIFO is same */ + mas->fifo_width_bits = geni_se_get_tx_fifo_width(se); + + /* + * Hardware programming guide suggests to configure + * RX FIFO RFR level to fifo_depth-2. + */ + geni_se_init(se, mas->tx_fifo_depth - 3, mas->tx_fifo_depth - 2); + /* Transmit an entire FIFO worth of data per IRQ */ + mas->tx_wm = 1; + ver = geni_se_get_qup_hw_version(se); + major = GENI_SE_VERSION_MAJOR(ver); + minor = GENI_SE_VERSION_MINOR(ver); + + if (major == 1 && minor == 0) + mas->oversampling = 2; + else + mas->oversampling = 1; + + fifo_disable = readl(se->base + GENI_IF_DISABLE_RO) & FIFO_IF_DISABLE; + switch (fifo_disable) { + case 1: + ret = spi_geni_grab_gpi_chan(mas); + if (!ret) { /* success case */ + mas->cur_xfer_mode = GENI_GPI_DMA; + geni_se_select_mode(se, GENI_GPI_DMA); + dev_dbg(mas->dev, "Using GPI DMA mode for SPI\n"); + break; + } else if (ret == -EPROBE_DEFER) { + goto out_pm; + } + /* + * in case of failure to get dma channel, we can still do the + * FIFO mode, so fallthrough + */ + dev_warn(mas->dev, "FIFO mode disabled, but couldn't get DMA, fall back to FIFO mode\n"); + fallthrough; + + case 0: + mas->cur_xfer_mode = GENI_SE_FIFO; + geni_se_select_mode(se, GENI_SE_FIFO); + ret = 0; + break; + } + + /* We always control CS manually */ + spi_tx_cfg = readl(se->base + SE_SPI_TRANS_CFG); + spi_tx_cfg &= ~CS_TOGGLE; + writel(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG); + +out_pm: + pm_runtime_put(mas->dev); + return ret; +} + +static unsigned int geni_byte_per_fifo_word(struct spi_geni_master *mas) +{ + /* + * Calculate how many bytes we'll put in each FIFO word. If the + * transfer words don't pack cleanly into a FIFO word we'll just put + * one transfer word in each FIFO word. If they do pack we'll pack 'em. + */ + if (mas->fifo_width_bits % mas->cur_bits_per_word) + return roundup_pow_of_two(DIV_ROUND_UP(mas->cur_bits_per_word, + BITS_PER_BYTE)); + + return mas->fifo_width_bits / BITS_PER_BYTE; +} + +static bool geni_spi_handle_tx(struct spi_geni_master *mas) +{ + struct geni_se *se = &mas->se; + unsigned int max_bytes; + const u8 *tx_buf; + unsigned int bytes_per_fifo_word = geni_byte_per_fifo_word(mas); + unsigned int i = 0; + + /* Stop the watermark IRQ if nothing to send */ + if (!mas->cur_xfer) { + writel(0, se->base + SE_GENI_TX_WATERMARK_REG); + return false; + } + + max_bytes = (mas->tx_fifo_depth - mas->tx_wm) * bytes_per_fifo_word; + if (mas->tx_rem_bytes < max_bytes) + max_bytes = mas->tx_rem_bytes; + + tx_buf = mas->cur_xfer->tx_buf + mas->cur_xfer->len - mas->tx_rem_bytes; + while (i < max_bytes) { + unsigned int j; + unsigned int bytes_to_write; + u32 fifo_word = 0; + u8 *fifo_byte = (u8 *)&fifo_word; + + bytes_to_write = min(bytes_per_fifo_word, max_bytes - i); + for (j = 0; j < bytes_to_write; j++) + fifo_byte[j] = tx_buf[i++]; + iowrite32_rep(se->base + SE_GENI_TX_FIFOn, &fifo_word, 1); + } + mas->tx_rem_bytes -= max_bytes; + if (!mas->tx_rem_bytes) { + writel(0, se->base + SE_GENI_TX_WATERMARK_REG); + return false; + } + return true; +} + +static void geni_spi_handle_rx(struct spi_geni_master *mas) +{ + struct geni_se *se = &mas->se; + u32 rx_fifo_status; + unsigned int rx_bytes; + unsigned int rx_last_byte_valid; + u8 *rx_buf; + unsigned int bytes_per_fifo_word = geni_byte_per_fifo_word(mas); + unsigned int i = 0; + + rx_fifo_status = readl(se->base + SE_GENI_RX_FIFO_STATUS); + rx_bytes = (rx_fifo_status & RX_FIFO_WC_MSK) * bytes_per_fifo_word; + if (rx_fifo_status & RX_LAST) { + rx_last_byte_valid = rx_fifo_status & RX_LAST_BYTE_VALID_MSK; + rx_last_byte_valid >>= RX_LAST_BYTE_VALID_SHFT; + if (rx_last_byte_valid && rx_last_byte_valid < 4) + rx_bytes -= bytes_per_fifo_word - rx_last_byte_valid; + } + + /* Clear out the FIFO and bail if nowhere to put it */ + if (!mas->cur_xfer) { + for (i = 0; i < DIV_ROUND_UP(rx_bytes, bytes_per_fifo_word); i++) + readl(se->base + SE_GENI_RX_FIFOn); + return; + } + + if (mas->rx_rem_bytes < rx_bytes) + rx_bytes = mas->rx_rem_bytes; + + rx_buf = mas->cur_xfer->rx_buf + mas->cur_xfer->len - mas->rx_rem_bytes; + while (i < rx_bytes) { + u32 fifo_word = 0; + u8 *fifo_byte = (u8 *)&fifo_word; + unsigned int bytes_to_read; + unsigned int j; + + bytes_to_read = min(bytes_per_fifo_word, rx_bytes - i); + ioread32_rep(se->base + SE_GENI_RX_FIFOn, &fifo_word, 1); + for (j = 0; j < bytes_to_read; j++) + rx_buf[i++] = fifo_byte[j]; + } + mas->rx_rem_bytes -= rx_bytes; +} + +static void setup_fifo_xfer(struct spi_transfer *xfer, + struct spi_geni_master *mas, + u16 mode, struct spi_master *spi) +{ + u32 m_cmd = 0; + u32 len; + struct geni_se *se = &mas->se; + int ret; + + /* + * Ensure that our interrupt handler isn't still running from some + * prior command before we start messing with the hardware behind + * its back. We don't need to _keep_ the lock here since we're only + * worried about racing with out interrupt handler. The SPI core + * already handles making sure that we're not trying to do two + * transfers at once or setting a chip select and doing a transfer + * concurrently. + * + * NOTE: we actually _can't_ hold the lock here because possibly we + * might call clk_set_rate() which needs to be able to sleep. + */ + spin_lock_irq(&mas->lock); + spin_unlock_irq(&mas->lock); + + if (xfer->bits_per_word != mas->cur_bits_per_word) { + spi_setup_word_len(mas, mode, xfer->bits_per_word); + mas->cur_bits_per_word = xfer->bits_per_word; + } + + /* Speed and bits per word can be overridden per transfer */ + ret = geni_spi_set_clock_and_bw(mas, xfer->speed_hz); + if (ret) + return; + + mas->tx_rem_bytes = 0; + mas->rx_rem_bytes = 0; + + if (!(mas->cur_bits_per_word % MIN_WORD_LEN)) + len = xfer->len * BITS_PER_BYTE / mas->cur_bits_per_word; + else + len = xfer->len / (mas->cur_bits_per_word / BITS_PER_BYTE + 1); + len &= TRANS_LEN_MSK; + + mas->cur_xfer = xfer; + if (xfer->tx_buf) { + m_cmd |= SPI_TX_ONLY; + mas->tx_rem_bytes = xfer->len; + writel(len, se->base + SE_SPI_TX_TRANS_LEN); + } + + if (xfer->rx_buf) { + m_cmd |= SPI_RX_ONLY; + writel(len, se->base + SE_SPI_RX_TRANS_LEN); + mas->rx_rem_bytes = xfer->len; + } + + /* + * Lock around right before we start the transfer since our + * interrupt could come in at any time now. + */ + spin_lock_irq(&mas->lock); + geni_se_setup_m_cmd(se, m_cmd, FRAGMENTATION); + if (m_cmd & SPI_TX_ONLY) { + if (geni_spi_handle_tx(mas)) + writel(mas->tx_wm, se->base + SE_GENI_TX_WATERMARK_REG); + } + spin_unlock_irq(&mas->lock); +} + +static int spi_geni_transfer_one(struct spi_master *spi, + struct spi_device *slv, + struct spi_transfer *xfer) +{ + struct spi_geni_master *mas = spi_master_get_devdata(spi); + + if (spi_geni_is_abort_still_pending(mas)) + return -EBUSY; + + /* Terminate and return success for 0 byte length transfer */ + if (!xfer->len) + return 0; + + if (mas->cur_xfer_mode == GENI_SE_FIFO) { + setup_fifo_xfer(xfer, mas, slv->mode, spi); + return 1; + } + return setup_gsi_xfer(xfer, mas, slv, spi); +} + +static irqreturn_t geni_spi_isr(int irq, void *data) +{ + struct spi_master *spi = data; + struct spi_geni_master *mas = spi_master_get_devdata(spi); + struct geni_se *se = &mas->se; + u32 m_irq; + + m_irq = readl(se->base + SE_GENI_M_IRQ_STATUS); + if (!m_irq) + return IRQ_NONE; + + if (m_irq & (M_CMD_OVERRUN_EN | M_ILLEGAL_CMD_EN | M_CMD_FAILURE_EN | + M_RX_FIFO_RD_ERR_EN | M_RX_FIFO_WR_ERR_EN | + M_TX_FIFO_RD_ERR_EN | M_TX_FIFO_WR_ERR_EN)) + dev_warn(mas->dev, "Unexpected IRQ err status %#010x\n", m_irq); + + spin_lock(&mas->lock); + + if ((m_irq & M_RX_FIFO_WATERMARK_EN) || (m_irq & M_RX_FIFO_LAST_EN)) + geni_spi_handle_rx(mas); + + if (m_irq & M_TX_FIFO_WATERMARK_EN) + geni_spi_handle_tx(mas); + + if (m_irq & M_CMD_DONE_EN) { + if (mas->cur_xfer) { + spi_finalize_current_transfer(spi); + mas->cur_xfer = NULL; + /* + * If this happens, then a CMD_DONE came before all the + * Tx buffer bytes were sent out. This is unusual, log + * this condition and disable the WM interrupt to + * prevent the system from stalling due an interrupt + * storm. + * + * If this happens when all Rx bytes haven't been + * received, log the condition. The only known time + * this can happen is if bits_per_word != 8 and some + * registers that expect xfer lengths in num spi_words + * weren't written correctly. + */ + if (mas->tx_rem_bytes) { + writel(0, se->base + SE_GENI_TX_WATERMARK_REG); + dev_err(mas->dev, "Premature done. tx_rem = %d bpw%d\n", + mas->tx_rem_bytes, mas->cur_bits_per_word); + } + if (mas->rx_rem_bytes) + dev_err(mas->dev, "Premature done. rx_rem = %d bpw%d\n", + mas->rx_rem_bytes, mas->cur_bits_per_word); + } else { + complete(&mas->cs_done); + } + } + + if (m_irq & M_CMD_CANCEL_EN) + complete(&mas->cancel_done); + if (m_irq & M_CMD_ABORT_EN) + complete(&mas->abort_done); + + /* + * It's safe or a good idea to Ack all of our interrupts at the end + * of the function. Specifically: + * - M_CMD_DONE_EN / M_RX_FIFO_LAST_EN: Edge triggered interrupts and + * clearing Acks. Clearing at the end relies on nobody else having + * started a new transfer yet or else we could be clearing _their_ + * done bit, but everyone grabs the spinlock before starting a new + * transfer. + * - M_RX_FIFO_WATERMARK_EN / M_TX_FIFO_WATERMARK_EN: These appear + * to be "latched level" interrupts so it's important to clear them + * _after_ you've handled the condition and always safe to do so + * since they'll re-assert if they're still happening. + */ + writel(m_irq, se->base + SE_GENI_M_IRQ_CLEAR); + + spin_unlock(&mas->lock); + + return IRQ_HANDLED; +} + +static int spi_geni_probe(struct platform_device *pdev) +{ + int ret, irq; + struct spi_master *spi; + struct spi_geni_master *mas; + void __iomem *base; + struct clk *clk; + struct device *dev = &pdev->dev; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64)); + if (ret) + return dev_err_probe(dev, ret, "could not set DMA mask\n"); + + base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(base)) + return PTR_ERR(base); + + clk = devm_clk_get(dev, "se"); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + spi = devm_spi_alloc_master(dev, sizeof(*mas)); + if (!spi) + return -ENOMEM; + + platform_set_drvdata(pdev, spi); + mas = spi_master_get_devdata(spi); + mas->irq = irq; + mas->dev = dev; + mas->se.dev = dev; + mas->se.wrapper = dev_get_drvdata(dev->parent); + mas->se.base = base; + mas->se.clk = clk; + + ret = devm_pm_opp_set_clkname(&pdev->dev, "se"); + if (ret) + return ret; + /* OPP table is optional */ + ret = devm_pm_opp_of_add_table(&pdev->dev); + if (ret && ret != -ENODEV) { + dev_err(&pdev->dev, "invalid OPP table in device tree\n"); + return ret; + } + + spi->bus_num = -1; + spi->dev.of_node = dev->of_node; + spi->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_CS_HIGH; + spi->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32); + spi->num_chipselect = 4; + spi->max_speed_hz = 50000000; + spi->prepare_message = spi_geni_prepare_message; + spi->transfer_one = spi_geni_transfer_one; + spi->can_dma = geni_can_dma; + spi->dma_map_dev = dev->parent; + spi->auto_runtime_pm = true; + spi->handle_err = spi_geni_handle_err; + spi->use_gpio_descriptors = true; + + init_completion(&mas->cs_done); + init_completion(&mas->cancel_done); + init_completion(&mas->abort_done); + spin_lock_init(&mas->lock); + pm_runtime_use_autosuspend(&pdev->dev); + pm_runtime_set_autosuspend_delay(&pdev->dev, 250); + pm_runtime_enable(dev); + + ret = geni_icc_get(&mas->se, NULL); + if (ret) + goto spi_geni_probe_runtime_disable; + /* Set the bus quota to a reasonable value for register access */ + mas->se.icc_paths[GENI_TO_CORE].avg_bw = Bps_to_icc(CORE_2X_50_MHZ); + mas->se.icc_paths[CPU_TO_GENI].avg_bw = GENI_DEFAULT_BW; + + ret = geni_icc_set_bw(&mas->se); + if (ret) + goto spi_geni_probe_runtime_disable; + + ret = spi_geni_init(mas); + if (ret) + goto spi_geni_probe_runtime_disable; + + /* + * check the mode supported and set_cs for fifo mode only + * for dma (gsi) mode, the gsi will set cs based on params passed in + * TRE + */ + if (mas->cur_xfer_mode == GENI_SE_FIFO) + spi->set_cs = spi_geni_set_cs; + + /* + * TX is required per GSI spec, see setup_gsi_xfer(). + */ + if (mas->cur_xfer_mode == GENI_GPI_DMA) + spi->flags = SPI_CONTROLLER_MUST_TX; + + ret = request_irq(mas->irq, geni_spi_isr, 0, dev_name(dev), spi); + if (ret) + goto spi_geni_release_dma; + + ret = spi_register_master(spi); + if (ret) + goto spi_geni_probe_free_irq; + + return 0; +spi_geni_probe_free_irq: + free_irq(mas->irq, spi); +spi_geni_release_dma: + spi_geni_release_dma_chan(mas); +spi_geni_probe_runtime_disable: + pm_runtime_disable(dev); + return ret; +} + +static int spi_geni_remove(struct platform_device *pdev) +{ + struct spi_master *spi = platform_get_drvdata(pdev); + struct spi_geni_master *mas = spi_master_get_devdata(spi); + + /* Unregister _before_ disabling pm_runtime() so we stop transfers */ + spi_unregister_master(spi); + + spi_geni_release_dma_chan(mas); + + free_irq(mas->irq, spi); + pm_runtime_disable(&pdev->dev); + return 0; +} + +static int __maybe_unused spi_geni_runtime_suspend(struct device *dev) +{ + struct spi_master *spi = dev_get_drvdata(dev); + struct spi_geni_master *mas = spi_master_get_devdata(spi); + int ret; + + /* Drop the performance state vote */ + dev_pm_opp_set_rate(dev, 0); + + ret = geni_se_resources_off(&mas->se); + if (ret) + return ret; + + return geni_icc_disable(&mas->se); +} + +static int __maybe_unused spi_geni_runtime_resume(struct device *dev) +{ + struct spi_master *spi = dev_get_drvdata(dev); + struct spi_geni_master *mas = spi_master_get_devdata(spi); + int ret; + + ret = geni_icc_enable(&mas->se); + if (ret) + return ret; + + ret = geni_se_resources_on(&mas->se); + if (ret) + return ret; + + return dev_pm_opp_set_rate(mas->dev, mas->cur_sclk_hz); +} + +static int __maybe_unused spi_geni_suspend(struct device *dev) +{ + struct spi_master *spi = dev_get_drvdata(dev); + int ret; + + ret = spi_master_suspend(spi); + if (ret) + return ret; + + ret = pm_runtime_force_suspend(dev); + if (ret) + spi_master_resume(spi); + + return ret; +} + +static int __maybe_unused spi_geni_resume(struct device *dev) +{ + struct spi_master *spi = dev_get_drvdata(dev); + int ret; + + ret = pm_runtime_force_resume(dev); + if (ret) + return ret; + + ret = spi_master_resume(spi); + if (ret) + pm_runtime_force_suspend(dev); + + return ret; +} + +static const struct dev_pm_ops spi_geni_pm_ops = { + SET_RUNTIME_PM_OPS(spi_geni_runtime_suspend, + spi_geni_runtime_resume, NULL) + SET_SYSTEM_SLEEP_PM_OPS(spi_geni_suspend, spi_geni_resume) +}; + +static const struct of_device_id spi_geni_dt_match[] = { + { .compatible = "qcom,geni-spi" }, + {} +}; +MODULE_DEVICE_TABLE(of, spi_geni_dt_match); + +static struct platform_driver spi_geni_driver = { + .probe = spi_geni_probe, + .remove = spi_geni_remove, + .driver = { + .name = "geni_spi", + .pm = &spi_geni_pm_ops, + .of_match_table = spi_geni_dt_match, + }, +}; +module_platform_driver(spi_geni_driver); + +MODULE_DESCRIPTION("SPI driver for GENI based QUP cores"); +MODULE_LICENSE("GPL v2"); |