diff options
Diffstat (limited to 'drivers/spi/spi-atmel.c')
| -rw-r--r-- | drivers/spi/spi-atmel.c | 1798 |
1 files changed, 1798 insertions, 0 deletions
diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c new file mode 100644 index 0000000000..e073d54873 --- /dev/null +++ b/drivers/spi/spi-atmel.c @@ -0,0 +1,1798 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for Atmel AT32 and AT91 SPI Controllers + * + * Copyright (C) 2006 Atmel Corporation + */ + +#include <linux/kernel.h> +#include <linux/clk.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/delay.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/spi/spi.h> +#include <linux/slab.h> +#include <linux/of.h> + +#include <linux/io.h> +#include <linux/gpio/consumer.h> +#include <linux/pinctrl/consumer.h> +#include <linux/pm_runtime.h> +#include <linux/iopoll.h> +#include <trace/events/spi.h> + +/* SPI register offsets */ +#define SPI_CR 0x0000 +#define SPI_MR 0x0004 +#define SPI_RDR 0x0008 +#define SPI_TDR 0x000c +#define SPI_SR 0x0010 +#define SPI_IER 0x0014 +#define SPI_IDR 0x0018 +#define SPI_IMR 0x001c +#define SPI_CSR0 0x0030 +#define SPI_CSR1 0x0034 +#define SPI_CSR2 0x0038 +#define SPI_CSR3 0x003c +#define SPI_FMR 0x0040 +#define SPI_FLR 0x0044 +#define SPI_VERSION 0x00fc +#define SPI_RPR 0x0100 +#define SPI_RCR 0x0104 +#define SPI_TPR 0x0108 +#define SPI_TCR 0x010c +#define SPI_RNPR 0x0110 +#define SPI_RNCR 0x0114 +#define SPI_TNPR 0x0118 +#define SPI_TNCR 0x011c +#define SPI_PTCR 0x0120 +#define SPI_PTSR 0x0124 + +/* Bitfields in CR */ +#define SPI_SPIEN_OFFSET 0 +#define SPI_SPIEN_SIZE 1 +#define SPI_SPIDIS_OFFSET 1 +#define SPI_SPIDIS_SIZE 1 +#define SPI_SWRST_OFFSET 7 +#define SPI_SWRST_SIZE 1 +#define SPI_LASTXFER_OFFSET 24 +#define SPI_LASTXFER_SIZE 1 +#define SPI_TXFCLR_OFFSET 16 +#define SPI_TXFCLR_SIZE 1 +#define SPI_RXFCLR_OFFSET 17 +#define SPI_RXFCLR_SIZE 1 +#define SPI_FIFOEN_OFFSET 30 +#define SPI_FIFOEN_SIZE 1 +#define SPI_FIFODIS_OFFSET 31 +#define SPI_FIFODIS_SIZE 1 + +/* Bitfields in MR */ +#define SPI_MSTR_OFFSET 0 +#define SPI_MSTR_SIZE 1 +#define SPI_PS_OFFSET 1 +#define SPI_PS_SIZE 1 +#define SPI_PCSDEC_OFFSET 2 +#define SPI_PCSDEC_SIZE 1 +#define SPI_FDIV_OFFSET 3 +#define SPI_FDIV_SIZE 1 +#define SPI_MODFDIS_OFFSET 4 +#define SPI_MODFDIS_SIZE 1 +#define SPI_WDRBT_OFFSET 5 +#define SPI_WDRBT_SIZE 1 +#define SPI_LLB_OFFSET 7 +#define SPI_LLB_SIZE 1 +#define SPI_PCS_OFFSET 16 +#define SPI_PCS_SIZE 4 +#define SPI_DLYBCS_OFFSET 24 +#define SPI_DLYBCS_SIZE 8 + +/* Bitfields in RDR */ +#define SPI_RD_OFFSET 0 +#define SPI_RD_SIZE 16 + +/* Bitfields in TDR */ +#define SPI_TD_OFFSET 0 +#define SPI_TD_SIZE 16 + +/* Bitfields in SR */ +#define SPI_RDRF_OFFSET 0 +#define SPI_RDRF_SIZE 1 +#define SPI_TDRE_OFFSET 1 +#define SPI_TDRE_SIZE 1 +#define SPI_MODF_OFFSET 2 +#define SPI_MODF_SIZE 1 +#define SPI_OVRES_OFFSET 3 +#define SPI_OVRES_SIZE 1 +#define SPI_ENDRX_OFFSET 4 +#define SPI_ENDRX_SIZE 1 +#define SPI_ENDTX_OFFSET 5 +#define SPI_ENDTX_SIZE 1 +#define SPI_RXBUFF_OFFSET 6 +#define SPI_RXBUFF_SIZE 1 +#define SPI_TXBUFE_OFFSET 7 +#define SPI_TXBUFE_SIZE 1 +#define SPI_NSSR_OFFSET 8 +#define SPI_NSSR_SIZE 1 +#define SPI_TXEMPTY_OFFSET 9 +#define SPI_TXEMPTY_SIZE 1 +#define SPI_SPIENS_OFFSET 16 +#define SPI_SPIENS_SIZE 1 +#define SPI_TXFEF_OFFSET 24 +#define SPI_TXFEF_SIZE 1 +#define SPI_TXFFF_OFFSET 25 +#define SPI_TXFFF_SIZE 1 +#define SPI_TXFTHF_OFFSET 26 +#define SPI_TXFTHF_SIZE 1 +#define SPI_RXFEF_OFFSET 27 +#define SPI_RXFEF_SIZE 1 +#define SPI_RXFFF_OFFSET 28 +#define SPI_RXFFF_SIZE 1 +#define SPI_RXFTHF_OFFSET 29 +#define SPI_RXFTHF_SIZE 1 +#define SPI_TXFPTEF_OFFSET 30 +#define SPI_TXFPTEF_SIZE 1 +#define SPI_RXFPTEF_OFFSET 31 +#define SPI_RXFPTEF_SIZE 1 + +/* Bitfields in CSR0 */ +#define SPI_CPOL_OFFSET 0 +#define SPI_CPOL_SIZE 1 +#define SPI_NCPHA_OFFSET 1 +#define SPI_NCPHA_SIZE 1 +#define SPI_CSAAT_OFFSET 3 +#define SPI_CSAAT_SIZE 1 +#define SPI_BITS_OFFSET 4 +#define SPI_BITS_SIZE 4 +#define SPI_SCBR_OFFSET 8 +#define SPI_SCBR_SIZE 8 +#define SPI_DLYBS_OFFSET 16 +#define SPI_DLYBS_SIZE 8 +#define SPI_DLYBCT_OFFSET 24 +#define SPI_DLYBCT_SIZE 8 + +/* Bitfields in RCR */ +#define SPI_RXCTR_OFFSET 0 +#define SPI_RXCTR_SIZE 16 + +/* Bitfields in TCR */ +#define SPI_TXCTR_OFFSET 0 +#define SPI_TXCTR_SIZE 16 + +/* Bitfields in RNCR */ +#define SPI_RXNCR_OFFSET 0 +#define SPI_RXNCR_SIZE 16 + +/* Bitfields in TNCR */ +#define SPI_TXNCR_OFFSET 0 +#define SPI_TXNCR_SIZE 16 + +/* Bitfields in PTCR */ +#define SPI_RXTEN_OFFSET 0 +#define SPI_RXTEN_SIZE 1 +#define SPI_RXTDIS_OFFSET 1 +#define SPI_RXTDIS_SIZE 1 +#define SPI_TXTEN_OFFSET 8 +#define SPI_TXTEN_SIZE 1 +#define SPI_TXTDIS_OFFSET 9 +#define SPI_TXTDIS_SIZE 1 + +/* Bitfields in FMR */ +#define SPI_TXRDYM_OFFSET 0 +#define SPI_TXRDYM_SIZE 2 +#define SPI_RXRDYM_OFFSET 4 +#define SPI_RXRDYM_SIZE 2 +#define SPI_TXFTHRES_OFFSET 16 +#define SPI_TXFTHRES_SIZE 6 +#define SPI_RXFTHRES_OFFSET 24 +#define SPI_RXFTHRES_SIZE 6 + +/* Bitfields in FLR */ +#define SPI_TXFL_OFFSET 0 +#define SPI_TXFL_SIZE 6 +#define SPI_RXFL_OFFSET 16 +#define SPI_RXFL_SIZE 6 + +/* Constants for BITS */ +#define SPI_BITS_8_BPT 0 +#define SPI_BITS_9_BPT 1 +#define SPI_BITS_10_BPT 2 +#define SPI_BITS_11_BPT 3 +#define SPI_BITS_12_BPT 4 +#define SPI_BITS_13_BPT 5 +#define SPI_BITS_14_BPT 6 +#define SPI_BITS_15_BPT 7 +#define SPI_BITS_16_BPT 8 +#define SPI_ONE_DATA 0 +#define SPI_TWO_DATA 1 +#define SPI_FOUR_DATA 2 + +/* Bit manipulation macros */ +#define SPI_BIT(name) \ + (1 << SPI_##name##_OFFSET) +#define SPI_BF(name, value) \ + (((value) & ((1 << SPI_##name##_SIZE) - 1)) << SPI_##name##_OFFSET) +#define SPI_BFEXT(name, value) \ + (((value) >> SPI_##name##_OFFSET) & ((1 << SPI_##name##_SIZE) - 1)) +#define SPI_BFINS(name, value, old) \ + (((old) & ~(((1 << SPI_##name##_SIZE) - 1) << SPI_##name##_OFFSET)) \ + | SPI_BF(name, value)) + +/* Register access macros */ +#define spi_readl(port, reg) \ + readl_relaxed((port)->regs + SPI_##reg) +#define spi_writel(port, reg, value) \ + writel_relaxed((value), (port)->regs + SPI_##reg) +#define spi_writew(port, reg, value) \ + writew_relaxed((value), (port)->regs + SPI_##reg) + +/* use PIO for small transfers, avoiding DMA setup/teardown overhead and + * cache operations; better heuristics consider wordsize and bitrate. + */ +#define DMA_MIN_BYTES 16 + +#define SPI_DMA_MIN_TIMEOUT (msecs_to_jiffies(1000)) +#define SPI_DMA_TIMEOUT_PER_10K (msecs_to_jiffies(4)) + +#define AUTOSUSPEND_TIMEOUT 2000 + +struct atmel_spi_caps { + bool is_spi2; + bool has_wdrbt; + bool has_dma_support; + bool has_pdc_support; +}; + +/* + * The core SPI transfer engine just talks to a register bank to set up + * DMA transfers; transfer queue progress is driven by IRQs. The clock + * framework provides the base clock, subdivided for each spi_device. + */ +struct atmel_spi { + spinlock_t lock; + unsigned long flags; + + phys_addr_t phybase; + void __iomem *regs; + int irq; + struct clk *clk; + struct platform_device *pdev; + unsigned long spi_clk; + + struct spi_transfer *current_transfer; + int current_remaining_bytes; + int done_status; + dma_addr_t dma_addr_rx_bbuf; + dma_addr_t dma_addr_tx_bbuf; + void *addr_rx_bbuf; + void *addr_tx_bbuf; + + struct completion xfer_completion; + + struct atmel_spi_caps caps; + + bool use_dma; + bool use_pdc; + + bool keep_cs; + + u32 fifo_size; + bool last_polarity; + u8 native_cs_free; + u8 native_cs_for_gpio; +}; + +/* Controller-specific per-slave state */ +struct atmel_spi_device { + u32 csr; +}; + +#define SPI_MAX_DMA_XFER 65535 /* true for both PDC and DMA */ +#define INVALID_DMA_ADDRESS 0xffffffff + +/* + * This frequency can be anything supported by the controller, but to avoid + * unnecessary delay, the highest possible frequency is chosen. + * + * This frequency is the highest possible which is not interfering with other + * chip select registers (see Note for Serial Clock Bit Rate configuration in + * Atmel-11121F-ATARM-SAMA5D3-Series-Datasheet_02-Feb-16, page 1283) + */ +#define DUMMY_MSG_FREQUENCY 0x02 +/* + * 8 bits is the minimum data the controller is capable of sending. + * + * This message can be anything as it should not be treated by any SPI device. + */ +#define DUMMY_MSG 0xAA + +/* + * Version 2 of the SPI controller has + * - CR.LASTXFER + * - SPI_MR.DIV32 may become FDIV or must-be-zero (here: always zero) + * - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs) + * - SPI_CSRx.CSAAT + * - SPI_CSRx.SBCR allows faster clocking + */ +static bool atmel_spi_is_v2(struct atmel_spi *as) +{ + return as->caps.is_spi2; +} + +/* + * Send a dummy message. + * + * This is sometimes needed when using a CS GPIO to force clock transition when + * switching between devices with different polarities. + */ +static void atmel_spi_send_dummy(struct atmel_spi *as, struct spi_device *spi, int chip_select) +{ + u32 status; + u32 csr; + + /* + * Set a clock frequency to allow sending message on SPI bus. + * The frequency here can be anything, but is needed for + * the controller to send the data. + */ + csr = spi_readl(as, CSR0 + 4 * chip_select); + csr = SPI_BFINS(SCBR, DUMMY_MSG_FREQUENCY, csr); + spi_writel(as, CSR0 + 4 * chip_select, csr); + + /* + * Read all data coming from SPI bus, needed to be able to send + * the message. + */ + spi_readl(as, RDR); + while (spi_readl(as, SR) & SPI_BIT(RDRF)) { + spi_readl(as, RDR); + cpu_relax(); + } + + spi_writel(as, TDR, DUMMY_MSG); + + readl_poll_timeout_atomic(as->regs + SPI_SR, status, + (status & SPI_BIT(TXEMPTY)), 1, 1000); +} + + +/* + * Earlier SPI controllers (e.g. on at91rm9200) have a design bug whereby + * they assume that spi slave device state will not change on deselect, so + * that automagic deselection is OK. ("NPCSx rises if no data is to be + * transmitted") Not so! Workaround uses nCSx pins as GPIOs; or newer + * controllers have CSAAT and friends. + * + * Even controller newer than ar91rm9200, using GPIOs can make sens as + * it lets us support active-high chipselects despite the controller's + * belief that only active-low devices/systems exists. + * + * However, at91rm9200 has a second erratum whereby nCS0 doesn't work + * right when driven with GPIO. ("Mode Fault does not allow more than one + * Master on Chip Select 0.") No workaround exists for that ... so for + * nCS0 on that chip, we (a) don't use the GPIO, (b) can't support CS_HIGH, + * and (c) will trigger that first erratum in some cases. + * + * When changing the clock polarity, the SPI controller waits for the next + * transmission to enforce the default clock state. This may be an issue when + * using a GPIO as Chip Select: the clock level is applied only when the first + * packet is sent, once the CS has already been asserted. The workaround is to + * avoid this by sending a first (dummy) message before toggling the CS state. + */ +static void cs_activate(struct atmel_spi *as, struct spi_device *spi) +{ + struct atmel_spi_device *asd = spi->controller_state; + bool new_polarity; + int chip_select; + u32 mr; + + if (spi_get_csgpiod(spi, 0)) + chip_select = as->native_cs_for_gpio; + else + chip_select = spi_get_chipselect(spi, 0); + + if (atmel_spi_is_v2(as)) { + spi_writel(as, CSR0 + 4 * chip_select, asd->csr); + /* For the low SPI version, there is a issue that PDC transfer + * on CS1,2,3 needs SPI_CSR0.BITS config as SPI_CSR1,2,3.BITS + */ + spi_writel(as, CSR0, asd->csr); + if (as->caps.has_wdrbt) { + spi_writel(as, MR, + SPI_BF(PCS, ~(0x01 << chip_select)) + | SPI_BIT(WDRBT) + | SPI_BIT(MODFDIS) + | SPI_BIT(MSTR)); + } else { + spi_writel(as, MR, + SPI_BF(PCS, ~(0x01 << chip_select)) + | SPI_BIT(MODFDIS) + | SPI_BIT(MSTR)); + } + + mr = spi_readl(as, MR); + + /* + * Ensures the clock polarity is valid before we actually + * assert the CS to avoid spurious clock edges to be + * processed by the spi devices. + */ + if (spi_get_csgpiod(spi, 0)) { + new_polarity = (asd->csr & SPI_BIT(CPOL)) != 0; + if (new_polarity != as->last_polarity) { + /* + * Need to disable the GPIO before sending the dummy + * message because it is already set by the spi core. + */ + gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0), 0); + atmel_spi_send_dummy(as, spi, chip_select); + as->last_polarity = new_polarity; + gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0), 1); + } + } + } else { + u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0; + int i; + u32 csr; + + /* Make sure clock polarity is correct */ + for (i = 0; i < spi->controller->num_chipselect; i++) { + csr = spi_readl(as, CSR0 + 4 * i); + if ((csr ^ cpol) & SPI_BIT(CPOL)) + spi_writel(as, CSR0 + 4 * i, + csr ^ SPI_BIT(CPOL)); + } + + mr = spi_readl(as, MR); + mr = SPI_BFINS(PCS, ~(1 << chip_select), mr); + spi_writel(as, MR, mr); + } + + dev_dbg(&spi->dev, "activate NPCS, mr %08x\n", mr); +} + +static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi) +{ + int chip_select; + u32 mr; + + if (spi_get_csgpiod(spi, 0)) + chip_select = as->native_cs_for_gpio; + else + chip_select = spi_get_chipselect(spi, 0); + + /* only deactivate *this* device; sometimes transfers to + * another device may be active when this routine is called. + */ + mr = spi_readl(as, MR); + if (~SPI_BFEXT(PCS, mr) & (1 << chip_select)) { + mr = SPI_BFINS(PCS, 0xf, mr); + spi_writel(as, MR, mr); + } + + dev_dbg(&spi->dev, "DEactivate NPCS, mr %08x\n", mr); + + if (!spi_get_csgpiod(spi, 0)) + spi_writel(as, CR, SPI_BIT(LASTXFER)); +} + +static void atmel_spi_lock(struct atmel_spi *as) __acquires(&as->lock) +{ + spin_lock_irqsave(&as->lock, as->flags); +} + +static void atmel_spi_unlock(struct atmel_spi *as) __releases(&as->lock) +{ + spin_unlock_irqrestore(&as->lock, as->flags); +} + +static inline bool atmel_spi_is_vmalloc_xfer(struct spi_transfer *xfer) +{ + return is_vmalloc_addr(xfer->tx_buf) || is_vmalloc_addr(xfer->rx_buf); +} + +static inline bool atmel_spi_use_dma(struct atmel_spi *as, + struct spi_transfer *xfer) +{ + return as->use_dma && xfer->len >= DMA_MIN_BYTES; +} + +static bool atmel_spi_can_dma(struct spi_controller *host, + struct spi_device *spi, + struct spi_transfer *xfer) +{ + struct atmel_spi *as = spi_controller_get_devdata(host); + + if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) + return atmel_spi_use_dma(as, xfer) && + !atmel_spi_is_vmalloc_xfer(xfer); + else + return atmel_spi_use_dma(as, xfer); + +} + +static int atmel_spi_dma_slave_config(struct atmel_spi *as, u8 bits_per_word) +{ + struct spi_controller *host = platform_get_drvdata(as->pdev); + struct dma_slave_config slave_config; + int err = 0; + + if (bits_per_word > 8) { + slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; + slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; + } else { + slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + } + + slave_config.dst_addr = (dma_addr_t)as->phybase + SPI_TDR; + slave_config.src_addr = (dma_addr_t)as->phybase + SPI_RDR; + slave_config.src_maxburst = 1; + slave_config.dst_maxburst = 1; + slave_config.device_fc = false; + + /* + * This driver uses fixed peripheral select mode (PS bit set to '0' in + * the Mode Register). + * So according to the datasheet, when FIFOs are available (and + * enabled), the Transmit FIFO operates in Multiple Data Mode. + * In this mode, up to 2 data, not 4, can be written into the Transmit + * Data Register in a single access. + * However, the first data has to be written into the lowest 16 bits and + * the second data into the highest 16 bits of the Transmit + * Data Register. For 8bit data (the most frequent case), it would + * require to rework tx_buf so each data would actually fit 16 bits. + * So we'd rather write only one data at the time. Hence the transmit + * path works the same whether FIFOs are available (and enabled) or not. + */ + if (dmaengine_slave_config(host->dma_tx, &slave_config)) { + dev_err(&as->pdev->dev, + "failed to configure tx dma channel\n"); + err = -EINVAL; + } + + /* + * This driver configures the spi controller for host mode (MSTR bit + * set to '1' in the Mode Register). + * So according to the datasheet, when FIFOs are available (and + * enabled), the Receive FIFO operates in Single Data Mode. + * So the receive path works the same whether FIFOs are available (and + * enabled) or not. + */ + if (dmaengine_slave_config(host->dma_rx, &slave_config)) { + dev_err(&as->pdev->dev, + "failed to configure rx dma channel\n"); + err = -EINVAL; + } + + return err; +} + +static int atmel_spi_configure_dma(struct spi_controller *host, + struct atmel_spi *as) +{ + struct device *dev = &as->pdev->dev; + int err; + + host->dma_tx = dma_request_chan(dev, "tx"); + if (IS_ERR(host->dma_tx)) { + err = PTR_ERR(host->dma_tx); + dev_dbg(dev, "No TX DMA channel, DMA is disabled\n"); + goto error_clear; + } + + host->dma_rx = dma_request_chan(dev, "rx"); + if (IS_ERR(host->dma_rx)) { + err = PTR_ERR(host->dma_rx); + /* + * No reason to check EPROBE_DEFER here since we have already + * requested tx channel. + */ + dev_dbg(dev, "No RX DMA channel, DMA is disabled\n"); + goto error; + } + + err = atmel_spi_dma_slave_config(as, 8); + if (err) + goto error; + + dev_info(&as->pdev->dev, + "Using %s (tx) and %s (rx) for DMA transfers\n", + dma_chan_name(host->dma_tx), + dma_chan_name(host->dma_rx)); + + return 0; +error: + if (!IS_ERR(host->dma_rx)) + dma_release_channel(host->dma_rx); + if (!IS_ERR(host->dma_tx)) + dma_release_channel(host->dma_tx); +error_clear: + host->dma_tx = host->dma_rx = NULL; + return err; +} + +static void atmel_spi_stop_dma(struct spi_controller *host) +{ + if (host->dma_rx) + dmaengine_terminate_all(host->dma_rx); + if (host->dma_tx) + dmaengine_terminate_all(host->dma_tx); +} + +static void atmel_spi_release_dma(struct spi_controller *host) +{ + if (host->dma_rx) { + dma_release_channel(host->dma_rx); + host->dma_rx = NULL; + } + if (host->dma_tx) { + dma_release_channel(host->dma_tx); + host->dma_tx = NULL; + } +} + +/* This function is called by the DMA driver from tasklet context */ +static void dma_callback(void *data) +{ + struct spi_controller *host = data; + struct atmel_spi *as = spi_controller_get_devdata(host); + + if (is_vmalloc_addr(as->current_transfer->rx_buf) && + IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { + memcpy(as->current_transfer->rx_buf, as->addr_rx_bbuf, + as->current_transfer->len); + } + complete(&as->xfer_completion); +} + +/* + * Next transfer using PIO without FIFO. + */ +static void atmel_spi_next_xfer_single(struct spi_controller *host, + struct spi_transfer *xfer) +{ + struct atmel_spi *as = spi_controller_get_devdata(host); + unsigned long xfer_pos = xfer->len - as->current_remaining_bytes; + + dev_vdbg(host->dev.parent, "atmel_spi_next_xfer_pio\n"); + + /* Make sure data is not remaining in RDR */ + spi_readl(as, RDR); + while (spi_readl(as, SR) & SPI_BIT(RDRF)) { + spi_readl(as, RDR); + cpu_relax(); + } + + if (xfer->bits_per_word > 8) + spi_writel(as, TDR, *(u16 *)(xfer->tx_buf + xfer_pos)); + else + spi_writel(as, TDR, *(u8 *)(xfer->tx_buf + xfer_pos)); + + dev_dbg(host->dev.parent, + " start pio xfer %p: len %u tx %p rx %p bitpw %d\n", + xfer, xfer->len, xfer->tx_buf, xfer->rx_buf, + xfer->bits_per_word); + + /* Enable relevant interrupts */ + spi_writel(as, IER, SPI_BIT(RDRF) | SPI_BIT(OVRES)); +} + +/* + * Next transfer using PIO with FIFO. + */ +static void atmel_spi_next_xfer_fifo(struct spi_controller *host, + struct spi_transfer *xfer) +{ + struct atmel_spi *as = spi_controller_get_devdata(host); + u32 current_remaining_data, num_data; + u32 offset = xfer->len - as->current_remaining_bytes; + const u16 *words = (const u16 *)((u8 *)xfer->tx_buf + offset); + const u8 *bytes = (const u8 *)((u8 *)xfer->tx_buf + offset); + u16 td0, td1; + u32 fifomr; + + dev_vdbg(host->dev.parent, "atmel_spi_next_xfer_fifo\n"); + + /* Compute the number of data to transfer in the current iteration */ + current_remaining_data = ((xfer->bits_per_word > 8) ? + ((u32)as->current_remaining_bytes >> 1) : + (u32)as->current_remaining_bytes); + num_data = min(current_remaining_data, as->fifo_size); + + /* Flush RX and TX FIFOs */ + spi_writel(as, CR, SPI_BIT(RXFCLR) | SPI_BIT(TXFCLR)); + while (spi_readl(as, FLR)) + cpu_relax(); + + /* Set RX FIFO Threshold to the number of data to transfer */ + fifomr = spi_readl(as, FMR); + spi_writel(as, FMR, SPI_BFINS(RXFTHRES, num_data, fifomr)); + + /* Clear FIFO flags in the Status Register, especially RXFTHF */ + (void)spi_readl(as, SR); + + /* Fill TX FIFO */ + while (num_data >= 2) { + if (xfer->bits_per_word > 8) { + td0 = *words++; + td1 = *words++; + } else { + td0 = *bytes++; + td1 = *bytes++; + } + + spi_writel(as, TDR, (td1 << 16) | td0); + num_data -= 2; + } + + if (num_data) { + if (xfer->bits_per_word > 8) + td0 = *words++; + else + td0 = *bytes++; + + spi_writew(as, TDR, td0); + num_data--; + } + + dev_dbg(host->dev.parent, + " start fifo xfer %p: len %u tx %p rx %p bitpw %d\n", + xfer, xfer->len, xfer->tx_buf, xfer->rx_buf, + xfer->bits_per_word); + + /* + * Enable RX FIFO Threshold Flag interrupt to be notified about + * transfer completion. + */ + spi_writel(as, IER, SPI_BIT(RXFTHF) | SPI_BIT(OVRES)); +} + +/* + * Next transfer using PIO. + */ +static void atmel_spi_next_xfer_pio(struct spi_controller *host, + struct spi_transfer *xfer) +{ + struct atmel_spi *as = spi_controller_get_devdata(host); + + if (as->fifo_size) + atmel_spi_next_xfer_fifo(host, xfer); + else + atmel_spi_next_xfer_single(host, xfer); +} + +/* + * Submit next transfer for DMA. + */ +static int atmel_spi_next_xfer_dma_submit(struct spi_controller *host, + struct spi_transfer *xfer, + u32 *plen) +{ + struct atmel_spi *as = spi_controller_get_devdata(host); + struct dma_chan *rxchan = host->dma_rx; + struct dma_chan *txchan = host->dma_tx; + struct dma_async_tx_descriptor *rxdesc; + struct dma_async_tx_descriptor *txdesc; + dma_cookie_t cookie; + + dev_vdbg(host->dev.parent, "atmel_spi_next_xfer_dma_submit\n"); + + /* Check that the channels are available */ + if (!rxchan || !txchan) + return -ENODEV; + + + *plen = xfer->len; + + if (atmel_spi_dma_slave_config(as, xfer->bits_per_word)) + goto err_exit; + + /* Send both scatterlists */ + if (atmel_spi_is_vmalloc_xfer(xfer) && + IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { + rxdesc = dmaengine_prep_slave_single(rxchan, + as->dma_addr_rx_bbuf, + xfer->len, + DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | + DMA_CTRL_ACK); + } else { + rxdesc = dmaengine_prep_slave_sg(rxchan, + xfer->rx_sg.sgl, + xfer->rx_sg.nents, + DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | + DMA_CTRL_ACK); + } + if (!rxdesc) + goto err_dma; + + if (atmel_spi_is_vmalloc_xfer(xfer) && + IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { + memcpy(as->addr_tx_bbuf, xfer->tx_buf, xfer->len); + txdesc = dmaengine_prep_slave_single(txchan, + as->dma_addr_tx_bbuf, + xfer->len, DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | + DMA_CTRL_ACK); + } else { + txdesc = dmaengine_prep_slave_sg(txchan, + xfer->tx_sg.sgl, + xfer->tx_sg.nents, + DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | + DMA_CTRL_ACK); + } + if (!txdesc) + goto err_dma; + + dev_dbg(host->dev.parent, + " start dma xfer %p: len %u tx %p/%08llx rx %p/%08llx\n", + xfer, xfer->len, xfer->tx_buf, (unsigned long long)xfer->tx_dma, + xfer->rx_buf, (unsigned long long)xfer->rx_dma); + + /* Enable relevant interrupts */ + spi_writel(as, IER, SPI_BIT(OVRES)); + + /* Put the callback on the RX transfer only, that should finish last */ + rxdesc->callback = dma_callback; + rxdesc->callback_param = host; + + /* Submit and fire RX and TX with TX last so we're ready to read! */ + cookie = rxdesc->tx_submit(rxdesc); + if (dma_submit_error(cookie)) + goto err_dma; + cookie = txdesc->tx_submit(txdesc); + if (dma_submit_error(cookie)) + goto err_dma; + rxchan->device->device_issue_pending(rxchan); + txchan->device->device_issue_pending(txchan); + + return 0; + +err_dma: + spi_writel(as, IDR, SPI_BIT(OVRES)); + atmel_spi_stop_dma(host); +err_exit: + return -ENOMEM; +} + +static void atmel_spi_next_xfer_data(struct spi_controller *host, + struct spi_transfer *xfer, + dma_addr_t *tx_dma, + dma_addr_t *rx_dma, + u32 *plen) +{ + *rx_dma = xfer->rx_dma + xfer->len - *plen; + *tx_dma = xfer->tx_dma + xfer->len - *plen; + if (*plen > host->max_dma_len) + *plen = host->max_dma_len; +} + +static int atmel_spi_set_xfer_speed(struct atmel_spi *as, + struct spi_device *spi, + struct spi_transfer *xfer) +{ + u32 scbr, csr; + unsigned long bus_hz; + int chip_select; + + if (spi_get_csgpiod(spi, 0)) + chip_select = as->native_cs_for_gpio; + else + chip_select = spi_get_chipselect(spi, 0); + + /* v1 chips start out at half the peripheral bus speed. */ + bus_hz = as->spi_clk; + if (!atmel_spi_is_v2(as)) + bus_hz /= 2; + + /* + * Calculate the lowest divider that satisfies the + * constraint, assuming div32/fdiv/mbz == 0. + */ + scbr = DIV_ROUND_UP(bus_hz, xfer->speed_hz); + + /* + * If the resulting divider doesn't fit into the + * register bitfield, we can't satisfy the constraint. + */ + if (scbr >= (1 << SPI_SCBR_SIZE)) { + dev_err(&spi->dev, + "setup: %d Hz too slow, scbr %u; min %ld Hz\n", + xfer->speed_hz, scbr, bus_hz/255); + return -EINVAL; + } + if (scbr == 0) { + dev_err(&spi->dev, + "setup: %d Hz too high, scbr %u; max %ld Hz\n", + xfer->speed_hz, scbr, bus_hz); + return -EINVAL; + } + csr = spi_readl(as, CSR0 + 4 * chip_select); + csr = SPI_BFINS(SCBR, scbr, csr); + spi_writel(as, CSR0 + 4 * chip_select, csr); + xfer->effective_speed_hz = bus_hz / scbr; + + return 0; +} + +/* + * Submit next transfer for PDC. + * lock is held, spi irq is blocked + */ +static void atmel_spi_pdc_next_xfer(struct spi_controller *host, + struct spi_transfer *xfer) +{ + struct atmel_spi *as = spi_controller_get_devdata(host); + u32 len; + dma_addr_t tx_dma, rx_dma; + + spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); + + len = as->current_remaining_bytes; + atmel_spi_next_xfer_data(host, xfer, &tx_dma, &rx_dma, &len); + as->current_remaining_bytes -= len; + + spi_writel(as, RPR, rx_dma); + spi_writel(as, TPR, tx_dma); + + if (xfer->bits_per_word > 8) + len >>= 1; + spi_writel(as, RCR, len); + spi_writel(as, TCR, len); + + dev_dbg(&host->dev, + " start xfer %p: len %u tx %p/%08llx rx %p/%08llx\n", + xfer, xfer->len, xfer->tx_buf, + (unsigned long long)xfer->tx_dma, xfer->rx_buf, + (unsigned long long)xfer->rx_dma); + + if (as->current_remaining_bytes) { + len = as->current_remaining_bytes; + atmel_spi_next_xfer_data(host, xfer, &tx_dma, &rx_dma, &len); + as->current_remaining_bytes -= len; + + spi_writel(as, RNPR, rx_dma); + spi_writel(as, TNPR, tx_dma); + + if (xfer->bits_per_word > 8) + len >>= 1; + spi_writel(as, RNCR, len); + spi_writel(as, TNCR, len); + + dev_dbg(&host->dev, + " next xfer %p: len %u tx %p/%08llx rx %p/%08llx\n", + xfer, xfer->len, xfer->tx_buf, + (unsigned long long)xfer->tx_dma, xfer->rx_buf, + (unsigned long long)xfer->rx_dma); + } + + /* REVISIT: We're waiting for RXBUFF before we start the next + * transfer because we need to handle some difficult timing + * issues otherwise. If we wait for TXBUFE in one transfer and + * then starts waiting for RXBUFF in the next, it's difficult + * to tell the difference between the RXBUFF interrupt we're + * actually waiting for and the RXBUFF interrupt of the + * previous transfer. + * + * It should be doable, though. Just not now... + */ + spi_writel(as, IER, SPI_BIT(RXBUFF) | SPI_BIT(OVRES)); + spi_writel(as, PTCR, SPI_BIT(TXTEN) | SPI_BIT(RXTEN)); +} + +/* + * For DMA, tx_buf/tx_dma have the same relationship as rx_buf/rx_dma: + * - The buffer is either valid for CPU access, else NULL + * - If the buffer is valid, so is its DMA address + * + * This driver manages the dma address unless message->is_dma_mapped. + */ +static int +atmel_spi_dma_map_xfer(struct atmel_spi *as, struct spi_transfer *xfer) +{ + struct device *dev = &as->pdev->dev; + + xfer->tx_dma = xfer->rx_dma = INVALID_DMA_ADDRESS; + if (xfer->tx_buf) { + /* tx_buf is a const void* where we need a void * for the dma + * mapping */ + void *nonconst_tx = (void *)xfer->tx_buf; + + xfer->tx_dma = dma_map_single(dev, + nonconst_tx, xfer->len, + DMA_TO_DEVICE); + if (dma_mapping_error(dev, xfer->tx_dma)) + return -ENOMEM; + } + if (xfer->rx_buf) { + xfer->rx_dma = dma_map_single(dev, + xfer->rx_buf, xfer->len, + DMA_FROM_DEVICE); + if (dma_mapping_error(dev, xfer->rx_dma)) { + if (xfer->tx_buf) + dma_unmap_single(dev, + xfer->tx_dma, xfer->len, + DMA_TO_DEVICE); + return -ENOMEM; + } + } + return 0; +} + +static void atmel_spi_dma_unmap_xfer(struct spi_controller *host, + struct spi_transfer *xfer) +{ + if (xfer->tx_dma != INVALID_DMA_ADDRESS) + dma_unmap_single(host->dev.parent, xfer->tx_dma, + xfer->len, DMA_TO_DEVICE); + if (xfer->rx_dma != INVALID_DMA_ADDRESS) + dma_unmap_single(host->dev.parent, xfer->rx_dma, + xfer->len, DMA_FROM_DEVICE); +} + +static void atmel_spi_disable_pdc_transfer(struct atmel_spi *as) +{ + spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); +} + +static void +atmel_spi_pump_single_data(struct atmel_spi *as, struct spi_transfer *xfer) +{ + u8 *rxp; + u16 *rxp16; + unsigned long xfer_pos = xfer->len - as->current_remaining_bytes; + + if (xfer->bits_per_word > 8) { + rxp16 = (u16 *)(((u8 *)xfer->rx_buf) + xfer_pos); + *rxp16 = spi_readl(as, RDR); + } else { + rxp = ((u8 *)xfer->rx_buf) + xfer_pos; + *rxp = spi_readl(as, RDR); + } + if (xfer->bits_per_word > 8) { + if (as->current_remaining_bytes > 2) + as->current_remaining_bytes -= 2; + else + as->current_remaining_bytes = 0; + } else { + as->current_remaining_bytes--; + } +} + +static void +atmel_spi_pump_fifo_data(struct atmel_spi *as, struct spi_transfer *xfer) +{ + u32 fifolr = spi_readl(as, FLR); + u32 num_bytes, num_data = SPI_BFEXT(RXFL, fifolr); + u32 offset = xfer->len - as->current_remaining_bytes; + u16 *words = (u16 *)((u8 *)xfer->rx_buf + offset); + u8 *bytes = (u8 *)((u8 *)xfer->rx_buf + offset); + u16 rd; /* RD field is the lowest 16 bits of RDR */ + + /* Update the number of remaining bytes to transfer */ + num_bytes = ((xfer->bits_per_word > 8) ? + (num_data << 1) : + num_data); + + if (as->current_remaining_bytes > num_bytes) + as->current_remaining_bytes -= num_bytes; + else + as->current_remaining_bytes = 0; + + /* Handle odd number of bytes when data are more than 8bit width */ + if (xfer->bits_per_word > 8) + as->current_remaining_bytes &= ~0x1; + + /* Read data */ + while (num_data) { + rd = spi_readl(as, RDR); + if (xfer->bits_per_word > 8) + *words++ = rd; + else + *bytes++ = rd; + num_data--; + } +} + +/* Called from IRQ + * + * Must update "current_remaining_bytes" to keep track of data + * to transfer. + */ +static void +atmel_spi_pump_pio_data(struct atmel_spi *as, struct spi_transfer *xfer) +{ + if (as->fifo_size) + atmel_spi_pump_fifo_data(as, xfer); + else + atmel_spi_pump_single_data(as, xfer); +} + +/* Interrupt + * + */ +static irqreturn_t +atmel_spi_pio_interrupt(int irq, void *dev_id) +{ + struct spi_controller *host = dev_id; + struct atmel_spi *as = spi_controller_get_devdata(host); + u32 status, pending, imr; + struct spi_transfer *xfer; + int ret = IRQ_NONE; + + imr = spi_readl(as, IMR); + status = spi_readl(as, SR); + pending = status & imr; + + if (pending & SPI_BIT(OVRES)) { + ret = IRQ_HANDLED; + spi_writel(as, IDR, SPI_BIT(OVRES)); + dev_warn(host->dev.parent, "overrun\n"); + + /* + * When we get an overrun, we disregard the current + * transfer. Data will not be copied back from any + * bounce buffer and msg->actual_len will not be + * updated with the last xfer. + * + * We will also not process any remaning transfers in + * the message. + */ + as->done_status = -EIO; + smp_wmb(); + + /* Clear any overrun happening while cleaning up */ + spi_readl(as, SR); + + complete(&as->xfer_completion); + + } else if (pending & (SPI_BIT(RDRF) | SPI_BIT(RXFTHF))) { + atmel_spi_lock(as); + + if (as->current_remaining_bytes) { + ret = IRQ_HANDLED; + xfer = as->current_transfer; + atmel_spi_pump_pio_data(as, xfer); + if (!as->current_remaining_bytes) + spi_writel(as, IDR, pending); + + complete(&as->xfer_completion); + } + + atmel_spi_unlock(as); + } else { + WARN_ONCE(pending, "IRQ not handled, pending = %x\n", pending); + ret = IRQ_HANDLED; + spi_writel(as, IDR, pending); + } + + return ret; +} + +static irqreturn_t +atmel_spi_pdc_interrupt(int irq, void *dev_id) +{ + struct spi_controller *host = dev_id; + struct atmel_spi *as = spi_controller_get_devdata(host); + u32 status, pending, imr; + int ret = IRQ_NONE; + + imr = spi_readl(as, IMR); + status = spi_readl(as, SR); + pending = status & imr; + + if (pending & SPI_BIT(OVRES)) { + + ret = IRQ_HANDLED; + + spi_writel(as, IDR, (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX) + | SPI_BIT(OVRES))); + + /* Clear any overrun happening while cleaning up */ + spi_readl(as, SR); + + as->done_status = -EIO; + + complete(&as->xfer_completion); + + } else if (pending & (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX))) { + ret = IRQ_HANDLED; + + spi_writel(as, IDR, pending); + + complete(&as->xfer_completion); + } + + return ret; +} + +static int atmel_word_delay_csr(struct spi_device *spi, struct atmel_spi *as) +{ + struct spi_delay *delay = &spi->word_delay; + u32 value = delay->value; + + switch (delay->unit) { + case SPI_DELAY_UNIT_NSECS: + value /= 1000; + break; + case SPI_DELAY_UNIT_USECS: + break; + default: + return -EINVAL; + } + + return (as->spi_clk / 1000000 * value) >> 5; +} + +static void initialize_native_cs_for_gpio(struct atmel_spi *as) +{ + int i; + struct spi_controller *host = platform_get_drvdata(as->pdev); + + if (!as->native_cs_free) + return; /* already initialized */ + + if (!host->cs_gpiods) + return; /* No CS GPIO */ + + /* + * On the first version of the controller (AT91RM9200), CS0 + * can't be used associated with GPIO + */ + if (atmel_spi_is_v2(as)) + i = 0; + else + i = 1; + + for (; i < 4; i++) + if (host->cs_gpiods[i]) + as->native_cs_free |= BIT(i); + + if (as->native_cs_free) + as->native_cs_for_gpio = ffs(as->native_cs_free); +} + +static int atmel_spi_setup(struct spi_device *spi) +{ + struct atmel_spi *as; + struct atmel_spi_device *asd; + u32 csr; + unsigned int bits = spi->bits_per_word; + int chip_select; + int word_delay_csr; + + as = spi_controller_get_devdata(spi->controller); + + /* see notes above re chipselect */ + if (!spi_get_csgpiod(spi, 0) && (spi->mode & SPI_CS_HIGH)) { + dev_warn(&spi->dev, "setup: non GPIO CS can't be active-high\n"); + return -EINVAL; + } + + /* Setup() is called during spi_register_controller(aka + * spi_register_master) but after all membmers of the cs_gpiod + * array have been filled, so we can looked for which native + * CS will be free for using with GPIO + */ + initialize_native_cs_for_gpio(as); + + if (spi_get_csgpiod(spi, 0) && as->native_cs_free) { + dev_err(&spi->dev, + "No native CS available to support this GPIO CS\n"); + return -EBUSY; + } + + if (spi_get_csgpiod(spi, 0)) + chip_select = as->native_cs_for_gpio; + else + chip_select = spi_get_chipselect(spi, 0); + + csr = SPI_BF(BITS, bits - 8); + if (spi->mode & SPI_CPOL) + csr |= SPI_BIT(CPOL); + if (!(spi->mode & SPI_CPHA)) + csr |= SPI_BIT(NCPHA); + + if (!spi_get_csgpiod(spi, 0)) + csr |= SPI_BIT(CSAAT); + csr |= SPI_BF(DLYBS, 0); + + word_delay_csr = atmel_word_delay_csr(spi, as); + if (word_delay_csr < 0) + return word_delay_csr; + + /* DLYBCT adds delays between words. This is useful for slow devices + * that need a bit of time to setup the next transfer. + */ + csr |= SPI_BF(DLYBCT, word_delay_csr); + + asd = spi->controller_state; + if (!asd) { + asd = kzalloc(sizeof(struct atmel_spi_device), GFP_KERNEL); + if (!asd) + return -ENOMEM; + + spi->controller_state = asd; + } + + asd->csr = csr; + + dev_dbg(&spi->dev, + "setup: bpw %u mode 0x%x -> csr%d %08x\n", + bits, spi->mode, spi_get_chipselect(spi, 0), csr); + + if (!atmel_spi_is_v2(as)) + spi_writel(as, CSR0 + 4 * chip_select, csr); + + return 0; +} + +static void atmel_spi_set_cs(struct spi_device *spi, bool enable) +{ + struct atmel_spi *as = spi_controller_get_devdata(spi->controller); + /* the core doesn't really pass us enable/disable, but CS HIGH vs CS LOW + * since we already have routines for activate/deactivate translate + * high/low to active/inactive + */ + enable = (!!(spi->mode & SPI_CS_HIGH) == enable); + + if (enable) { + cs_activate(as, spi); + } else { + cs_deactivate(as, spi); + } + +} + +static int atmel_spi_one_transfer(struct spi_controller *host, + struct spi_device *spi, + struct spi_transfer *xfer) +{ + struct atmel_spi *as; + u8 bits; + u32 len; + struct atmel_spi_device *asd; + int timeout; + int ret; + unsigned int dma_timeout; + long ret_timeout; + + as = spi_controller_get_devdata(host); + + asd = spi->controller_state; + bits = (asd->csr >> 4) & 0xf; + if (bits != xfer->bits_per_word - 8) { + dev_dbg(&spi->dev, + "you can't yet change bits_per_word in transfers\n"); + return -ENOPROTOOPT; + } + + /* + * DMA map early, for performance (empties dcache ASAP) and + * better fault reporting. + */ + if ((!host->cur_msg->is_dma_mapped) + && as->use_pdc) { + if (atmel_spi_dma_map_xfer(as, xfer) < 0) + return -ENOMEM; + } + + atmel_spi_set_xfer_speed(as, spi, xfer); + + as->done_status = 0; + as->current_transfer = xfer; + as->current_remaining_bytes = xfer->len; + while (as->current_remaining_bytes) { + reinit_completion(&as->xfer_completion); + + if (as->use_pdc) { + atmel_spi_lock(as); + atmel_spi_pdc_next_xfer(host, xfer); + atmel_spi_unlock(as); + } else if (atmel_spi_use_dma(as, xfer)) { + len = as->current_remaining_bytes; + ret = atmel_spi_next_xfer_dma_submit(host, + xfer, &len); + if (ret) { + dev_err(&spi->dev, + "unable to use DMA, fallback to PIO\n"); + as->done_status = ret; + break; + } else { + as->current_remaining_bytes -= len; + if (as->current_remaining_bytes < 0) + as->current_remaining_bytes = 0; + } + } else { + atmel_spi_lock(as); + atmel_spi_next_xfer_pio(host, xfer); + atmel_spi_unlock(as); + } + + dma_timeout = msecs_to_jiffies(spi_controller_xfer_timeout(host, xfer)); + ret_timeout = wait_for_completion_timeout(&as->xfer_completion, dma_timeout); + if (!ret_timeout) { + dev_err(&spi->dev, "spi transfer timeout\n"); + as->done_status = -EIO; + } + + if (as->done_status) + break; + } + + if (as->done_status) { + if (as->use_pdc) { + dev_warn(host->dev.parent, + "overrun (%u/%u remaining)\n", + spi_readl(as, TCR), spi_readl(as, RCR)); + + /* + * Clean up DMA registers and make sure the data + * registers are empty. + */ + spi_writel(as, RNCR, 0); + spi_writel(as, TNCR, 0); + spi_writel(as, RCR, 0); + spi_writel(as, TCR, 0); + for (timeout = 1000; timeout; timeout--) + if (spi_readl(as, SR) & SPI_BIT(TXEMPTY)) + break; + if (!timeout) + dev_warn(host->dev.parent, + "timeout waiting for TXEMPTY"); + while (spi_readl(as, SR) & SPI_BIT(RDRF)) + spi_readl(as, RDR); + + /* Clear any overrun happening while cleaning up */ + spi_readl(as, SR); + + } else if (atmel_spi_use_dma(as, xfer)) { + atmel_spi_stop_dma(host); + } + } + + if (!host->cur_msg->is_dma_mapped + && as->use_pdc) + atmel_spi_dma_unmap_xfer(host, xfer); + + if (as->use_pdc) + atmel_spi_disable_pdc_transfer(as); + + return as->done_status; +} + +static void atmel_spi_cleanup(struct spi_device *spi) +{ + struct atmel_spi_device *asd = spi->controller_state; + + if (!asd) + return; + + spi->controller_state = NULL; + kfree(asd); +} + +static inline unsigned int atmel_get_version(struct atmel_spi *as) +{ + return spi_readl(as, VERSION) & 0x00000fff; +} + +static void atmel_get_caps(struct atmel_spi *as) +{ + unsigned int version; + + version = atmel_get_version(as); + + as->caps.is_spi2 = version > 0x121; + as->caps.has_wdrbt = version >= 0x210; + as->caps.has_dma_support = version >= 0x212; + as->caps.has_pdc_support = version < 0x212; +} + +static void atmel_spi_init(struct atmel_spi *as) +{ + spi_writel(as, CR, SPI_BIT(SWRST)); + spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ + + /* It is recommended to enable FIFOs first thing after reset */ + if (as->fifo_size) + spi_writel(as, CR, SPI_BIT(FIFOEN)); + + if (as->caps.has_wdrbt) { + spi_writel(as, MR, SPI_BIT(WDRBT) | SPI_BIT(MODFDIS) + | SPI_BIT(MSTR)); + } else { + spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS)); + } + + if (as->use_pdc) + spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); + spi_writel(as, CR, SPI_BIT(SPIEN)); +} + +static int atmel_spi_probe(struct platform_device *pdev) +{ + struct resource *regs; + int irq; + struct clk *clk; + int ret; + struct spi_controller *host; + struct atmel_spi *as; + + /* Select default pin state */ + pinctrl_pm_select_default_state(&pdev->dev); + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + clk = devm_clk_get(&pdev->dev, "spi_clk"); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + /* setup spi core then atmel-specific driver state */ + host = spi_alloc_host(&pdev->dev, sizeof(*as)); + if (!host) + return -ENOMEM; + + /* the spi->mode bits understood by this driver: */ + host->use_gpio_descriptors = true; + host->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; + host->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 16); + host->dev.of_node = pdev->dev.of_node; + host->bus_num = pdev->id; + host->num_chipselect = 4; + host->setup = atmel_spi_setup; + host->flags = (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX | + SPI_CONTROLLER_GPIO_SS); + host->transfer_one = atmel_spi_one_transfer; + host->set_cs = atmel_spi_set_cs; + host->cleanup = atmel_spi_cleanup; + host->auto_runtime_pm = true; + host->max_dma_len = SPI_MAX_DMA_XFER; + host->can_dma = atmel_spi_can_dma; + platform_set_drvdata(pdev, host); + + as = spi_controller_get_devdata(host); + + spin_lock_init(&as->lock); + + as->pdev = pdev; + as->regs = devm_platform_get_and_ioremap_resource(pdev, 0, ®s); + if (IS_ERR(as->regs)) { + ret = PTR_ERR(as->regs); + goto out_unmap_regs; + } + as->phybase = regs->start; + as->irq = irq; + as->clk = clk; + + init_completion(&as->xfer_completion); + + atmel_get_caps(as); + + as->use_dma = false; + as->use_pdc = false; + if (as->caps.has_dma_support) { + ret = atmel_spi_configure_dma(host, as); + if (ret == 0) { + as->use_dma = true; + } else if (ret == -EPROBE_DEFER) { + goto out_unmap_regs; + } + } else if (as->caps.has_pdc_support) { + as->use_pdc = true; + } + + if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { + as->addr_rx_bbuf = dma_alloc_coherent(&pdev->dev, + SPI_MAX_DMA_XFER, + &as->dma_addr_rx_bbuf, + GFP_KERNEL | GFP_DMA); + if (!as->addr_rx_bbuf) { + as->use_dma = false; + } else { + as->addr_tx_bbuf = dma_alloc_coherent(&pdev->dev, + SPI_MAX_DMA_XFER, + &as->dma_addr_tx_bbuf, + GFP_KERNEL | GFP_DMA); + if (!as->addr_tx_bbuf) { + as->use_dma = false; + dma_free_coherent(&pdev->dev, SPI_MAX_DMA_XFER, + as->addr_rx_bbuf, + as->dma_addr_rx_bbuf); + } + } + if (!as->use_dma) + dev_info(host->dev.parent, + " can not allocate dma coherent memory\n"); + } + + if (as->caps.has_dma_support && !as->use_dma) + dev_info(&pdev->dev, "Atmel SPI Controller using PIO only\n"); + + if (as->use_pdc) { + ret = devm_request_irq(&pdev->dev, irq, atmel_spi_pdc_interrupt, + 0, dev_name(&pdev->dev), host); + } else { + ret = devm_request_irq(&pdev->dev, irq, atmel_spi_pio_interrupt, + 0, dev_name(&pdev->dev), host); + } + if (ret) + goto out_unmap_regs; + + /* Initialize the hardware */ + ret = clk_prepare_enable(clk); + if (ret) + goto out_free_irq; + + as->spi_clk = clk_get_rate(clk); + + as->fifo_size = 0; + if (!of_property_read_u32(pdev->dev.of_node, "atmel,fifo-size", + &as->fifo_size)) { + dev_info(&pdev->dev, "Using FIFO (%u data)\n", as->fifo_size); + } + + atmel_spi_init(as); + + pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT); + pm_runtime_use_autosuspend(&pdev->dev); + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + + ret = devm_spi_register_controller(&pdev->dev, host); + if (ret) + goto out_free_dma; + + /* go! */ + dev_info(&pdev->dev, "Atmel SPI Controller version 0x%x at 0x%08lx (irq %d)\n", + atmel_get_version(as), (unsigned long)regs->start, + irq); + + return 0; + +out_free_dma: + pm_runtime_disable(&pdev->dev); + pm_runtime_set_suspended(&pdev->dev); + + if (as->use_dma) + atmel_spi_release_dma(host); + + spi_writel(as, CR, SPI_BIT(SWRST)); + spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ + clk_disable_unprepare(clk); +out_free_irq: +out_unmap_regs: + spi_controller_put(host); + return ret; +} + +static void atmel_spi_remove(struct platform_device *pdev) +{ + struct spi_controller *host = platform_get_drvdata(pdev); + struct atmel_spi *as = spi_controller_get_devdata(host); + + pm_runtime_get_sync(&pdev->dev); + + /* reset the hardware and block queue progress */ + if (as->use_dma) { + atmel_spi_stop_dma(host); + atmel_spi_release_dma(host); + if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { + dma_free_coherent(&pdev->dev, SPI_MAX_DMA_XFER, + as->addr_tx_bbuf, + as->dma_addr_tx_bbuf); + dma_free_coherent(&pdev->dev, SPI_MAX_DMA_XFER, + as->addr_rx_bbuf, + as->dma_addr_rx_bbuf); + } + } + + spin_lock_irq(&as->lock); + spi_writel(as, CR, SPI_BIT(SWRST)); + spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ + spi_readl(as, SR); + spin_unlock_irq(&as->lock); + + clk_disable_unprepare(as->clk); + + pm_runtime_put_noidle(&pdev->dev); + pm_runtime_disable(&pdev->dev); +} + +static int atmel_spi_runtime_suspend(struct device *dev) +{ + struct spi_controller *host = dev_get_drvdata(dev); + struct atmel_spi *as = spi_controller_get_devdata(host); + + clk_disable_unprepare(as->clk); + pinctrl_pm_select_sleep_state(dev); + + return 0; +} + +static int atmel_spi_runtime_resume(struct device *dev) +{ + struct spi_controller *host = dev_get_drvdata(dev); + struct atmel_spi *as = spi_controller_get_devdata(host); + + pinctrl_pm_select_default_state(dev); + + return clk_prepare_enable(as->clk); +} + +static int atmel_spi_suspend(struct device *dev) +{ + struct spi_controller *host = dev_get_drvdata(dev); + int ret; + + /* Stop the queue running */ + ret = spi_controller_suspend(host); + if (ret) + return ret; + + if (!pm_runtime_suspended(dev)) + atmel_spi_runtime_suspend(dev); + + return 0; +} + +static int atmel_spi_resume(struct device *dev) +{ + struct spi_controller *host = dev_get_drvdata(dev); + struct atmel_spi *as = spi_controller_get_devdata(host); + int ret; + + ret = clk_prepare_enable(as->clk); + if (ret) + return ret; + + atmel_spi_init(as); + + clk_disable_unprepare(as->clk); + + if (!pm_runtime_suspended(dev)) { + ret = atmel_spi_runtime_resume(dev); + if (ret) + return ret; + } + + /* Start the queue running */ + return spi_controller_resume(host); +} + +static const struct dev_pm_ops atmel_spi_pm_ops = { + SYSTEM_SLEEP_PM_OPS(atmel_spi_suspend, atmel_spi_resume) + RUNTIME_PM_OPS(atmel_spi_runtime_suspend, + atmel_spi_runtime_resume, NULL) +}; + +static const struct of_device_id atmel_spi_dt_ids[] = { + { .compatible = "atmel,at91rm9200-spi" }, + { /* sentinel */ } +}; + +MODULE_DEVICE_TABLE(of, atmel_spi_dt_ids); + +static struct platform_driver atmel_spi_driver = { + .driver = { + .name = "atmel_spi", + .pm = pm_ptr(&atmel_spi_pm_ops), + .of_match_table = atmel_spi_dt_ids, + }, + .probe = atmel_spi_probe, + .remove_new = atmel_spi_remove, +}; +module_platform_driver(atmel_spi_driver); + +MODULE_DESCRIPTION("Atmel AT32/AT91 SPI Controller driver"); +MODULE_AUTHOR("Haavard Skinnemoen (Atmel)"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:atmel_spi"); |