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@ -70,12 +70,9 @@
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/**
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* struct ep93xx_spi - EP93xx SPI controller structure
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* @pdev: pointer to platform device
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* @clk: clock for the controller
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* @regs_base: pointer to ioremap()'d registers
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* @mmio: pointer to ioremap()'d registers
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* @sspdr_phys: physical address of the SSPDR register
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* @wait: wait here until given transfer is completed
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* @current_msg: message that is currently processed (or %NULL if none)
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* @tx: current byte in transfer to transmit
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* @rx: current byte in transfer to receive
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* @fifo_level: how full is FIFO (%0..%SPI_FIFO_SIZE - %1). Receiving one
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@ -90,12 +87,9 @@
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* the client
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*/
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struct ep93xx_spi {
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const struct platform_device *pdev;
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struct clk *clk;
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void __iomem *regs_base;
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void __iomem *mmio;
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unsigned long sspdr_phys;
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struct completion wait;
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struct spi_message *current_msg;
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size_t tx;
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size_t rx;
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size_t fifo_level;
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@ -111,91 +105,23 @@ struct ep93xx_spi {
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/* converts bits per word to CR0.DSS value */
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#define bits_per_word_to_dss(bpw) ((bpw) - 1)
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static void ep93xx_spi_write_u8(const struct ep93xx_spi *espi,
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u16 reg, u8 value)
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{
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writeb(value, espi->regs_base + reg);
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}
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static u8 ep93xx_spi_read_u8(const struct ep93xx_spi *spi, u16 reg)
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{
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return readb(spi->regs_base + reg);
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}
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static void ep93xx_spi_write_u16(const struct ep93xx_spi *espi,
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u16 reg, u16 value)
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{
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writew(value, espi->regs_base + reg);
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}
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static u16 ep93xx_spi_read_u16(const struct ep93xx_spi *spi, u16 reg)
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{
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return readw(spi->regs_base + reg);
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}
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static int ep93xx_spi_enable(const struct ep93xx_spi *espi)
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{
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u8 regval;
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int err;
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err = clk_enable(espi->clk);
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if (err)
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return err;
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regval = ep93xx_spi_read_u8(espi, SSPCR1);
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regval |= SSPCR1_SSE;
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ep93xx_spi_write_u8(espi, SSPCR1, regval);
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return 0;
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}
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static void ep93xx_spi_disable(const struct ep93xx_spi *espi)
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{
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u8 regval;
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regval = ep93xx_spi_read_u8(espi, SSPCR1);
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regval &= ~SSPCR1_SSE;
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ep93xx_spi_write_u8(espi, SSPCR1, regval);
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clk_disable(espi->clk);
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}
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static void ep93xx_spi_enable_interrupts(const struct ep93xx_spi *espi)
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{
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u8 regval;
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regval = ep93xx_spi_read_u8(espi, SSPCR1);
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regval |= (SSPCR1_RORIE | SSPCR1_TIE | SSPCR1_RIE);
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ep93xx_spi_write_u8(espi, SSPCR1, regval);
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}
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static void ep93xx_spi_disable_interrupts(const struct ep93xx_spi *espi)
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{
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u8 regval;
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regval = ep93xx_spi_read_u8(espi, SSPCR1);
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regval &= ~(SSPCR1_RORIE | SSPCR1_TIE | SSPCR1_RIE);
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ep93xx_spi_write_u8(espi, SSPCR1, regval);
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}
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/**
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* ep93xx_spi_calc_divisors() - calculates SPI clock divisors
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* @espi: ep93xx SPI controller struct
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* @master: SPI master
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* @rate: desired SPI output clock rate
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* @div_cpsr: pointer to return the cpsr (pre-scaler) divider
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* @div_scr: pointer to return the scr divider
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*/
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static int ep93xx_spi_calc_divisors(const struct ep93xx_spi *espi,
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static int ep93xx_spi_calc_divisors(struct spi_master *master,
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u32 rate, u8 *div_cpsr, u8 *div_scr)
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{
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struct spi_master *master = platform_get_drvdata(espi->pdev);
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struct ep93xx_spi *espi = spi_master_get_devdata(master);
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unsigned long spi_clk_rate = clk_get_rate(espi->clk);
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int cpsr, scr;
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/*
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* Make sure that max value is between values supported by the
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* controller. Note that minimum value is already checked in
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* ep93xx_spi_transfer_one_message().
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* controller.
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*/
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rate = clamp(rate, master->min_speed_hz, master->max_speed_hz);
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@ -220,26 +146,18 @@ static int ep93xx_spi_calc_divisors(const struct ep93xx_spi *espi,
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return -EINVAL;
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}
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static void ep93xx_spi_cs_control(struct spi_device *spi, bool enable)
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{
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if (spi->mode & SPI_CS_HIGH)
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enable = !enable;
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if (gpio_is_valid(spi->cs_gpio))
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gpio_set_value(spi->cs_gpio, !enable);
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}
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static int ep93xx_spi_chip_setup(const struct ep93xx_spi *espi,
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static int ep93xx_spi_chip_setup(struct spi_master *master,
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struct spi_device *spi,
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struct spi_transfer *xfer)
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{
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struct ep93xx_spi *espi = spi_master_get_devdata(master);
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u8 dss = bits_per_word_to_dss(xfer->bits_per_word);
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u8 div_cpsr = 0;
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u8 div_scr = 0;
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u16 cr0;
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int err;
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err = ep93xx_spi_calc_divisors(espi, xfer->speed_hz,
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err = ep93xx_spi_calc_divisors(master, xfer->speed_hz,
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&div_cpsr, &div_scr);
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if (err)
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return err;
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@ -248,51 +166,49 @@ static int ep93xx_spi_chip_setup(const struct ep93xx_spi *espi,
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cr0 |= (spi->mode & (SPI_CPHA | SPI_CPOL)) << SSPCR0_MODE_SHIFT;
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cr0 |= dss;
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dev_dbg(&espi->pdev->dev, "setup: mode %d, cpsr %d, scr %d, dss %d\n",
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dev_dbg(&master->dev, "setup: mode %d, cpsr %d, scr %d, dss %d\n",
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spi->mode, div_cpsr, div_scr, dss);
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dev_dbg(&espi->pdev->dev, "setup: cr0 %#x\n", cr0);
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dev_dbg(&master->dev, "setup: cr0 %#x\n", cr0);
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ep93xx_spi_write_u8(espi, SSPCPSR, div_cpsr);
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ep93xx_spi_write_u16(espi, SSPCR0, cr0);
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writel(div_cpsr, espi->mmio + SSPCPSR);
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writel(cr0, espi->mmio + SSPCR0);
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return 0;
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}
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static void ep93xx_do_write(struct ep93xx_spi *espi, struct spi_transfer *t)
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static void ep93xx_do_write(struct spi_master *master)
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{
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if (t->bits_per_word > 8) {
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u16 tx_val = 0;
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struct ep93xx_spi *espi = spi_master_get_devdata(master);
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struct spi_transfer *xfer = master->cur_msg->state;
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u32 val = 0;
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if (t->tx_buf)
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tx_val = ((u16 *)t->tx_buf)[espi->tx];
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ep93xx_spi_write_u16(espi, SSPDR, tx_val);
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espi->tx += sizeof(tx_val);
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if (xfer->bits_per_word > 8) {
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if (xfer->tx_buf)
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val = ((u16 *)xfer->tx_buf)[espi->tx];
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espi->tx += 2;
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} else {
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u8 tx_val = 0;
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if (t->tx_buf)
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tx_val = ((u8 *)t->tx_buf)[espi->tx];
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ep93xx_spi_write_u8(espi, SSPDR, tx_val);
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espi->tx += sizeof(tx_val);
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if (xfer->tx_buf)
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val = ((u8 *)xfer->tx_buf)[espi->tx];
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espi->tx += 1;
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}
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writel(val, espi->mmio + SSPDR);
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}
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static void ep93xx_do_read(struct ep93xx_spi *espi, struct spi_transfer *t)
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static void ep93xx_do_read(struct spi_master *master)
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{
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if (t->bits_per_word > 8) {
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u16 rx_val;
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struct ep93xx_spi *espi = spi_master_get_devdata(master);
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struct spi_transfer *xfer = master->cur_msg->state;
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u32 val;
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rx_val = ep93xx_spi_read_u16(espi, SSPDR);
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if (t->rx_buf)
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((u16 *)t->rx_buf)[espi->rx] = rx_val;
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espi->rx += sizeof(rx_val);
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val = readl(espi->mmio + SSPDR);
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if (xfer->bits_per_word > 8) {
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if (xfer->rx_buf)
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((u16 *)xfer->rx_buf)[espi->rx] = val;
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espi->rx += 2;
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} else {
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u8 rx_val;
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rx_val = ep93xx_spi_read_u8(espi, SSPDR);
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if (t->rx_buf)
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((u8 *)t->rx_buf)[espi->rx] = rx_val;
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espi->rx += sizeof(rx_val);
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if (xfer->rx_buf)
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((u8 *)xfer->rx_buf)[espi->rx] = val;
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espi->rx += 1;
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}
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}
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@ -307,44 +223,32 @@ static void ep93xx_do_read(struct ep93xx_spi *espi, struct spi_transfer *t)
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* When this function is finished, RX FIFO should be empty and TX FIFO should be
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* full.
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*/
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static int ep93xx_spi_read_write(struct ep93xx_spi *espi)
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static int ep93xx_spi_read_write(struct spi_master *master)
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{
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struct spi_message *msg = espi->current_msg;
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struct spi_transfer *t = msg->state;
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struct ep93xx_spi *espi = spi_master_get_devdata(master);
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struct spi_transfer *xfer = master->cur_msg->state;
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/* read as long as RX FIFO has frames in it */
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while ((ep93xx_spi_read_u8(espi, SSPSR) & SSPSR_RNE)) {
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ep93xx_do_read(espi, t);
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while ((readl(espi->mmio + SSPSR) & SSPSR_RNE)) {
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ep93xx_do_read(master);
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espi->fifo_level--;
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}
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/* write as long as TX FIFO has room */
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while (espi->fifo_level < SPI_FIFO_SIZE && espi->tx < t->len) {
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ep93xx_do_write(espi, t);
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while (espi->fifo_level < SPI_FIFO_SIZE && espi->tx < xfer->len) {
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ep93xx_do_write(master);
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espi->fifo_level++;
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}
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if (espi->rx == t->len)
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if (espi->rx == xfer->len)
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return 0;
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return -EINPROGRESS;
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}
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static void ep93xx_spi_pio_transfer(struct ep93xx_spi *espi)
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{
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/*
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* Now everything is set up for the current transfer. We prime the TX
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* FIFO, enable interrupts, and wait for the transfer to complete.
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*/
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if (ep93xx_spi_read_write(espi)) {
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ep93xx_spi_enable_interrupts(espi);
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wait_for_completion(&espi->wait);
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}
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}
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/**
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* ep93xx_spi_dma_prepare() - prepares a DMA transfer
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* @espi: ep93xx SPI controller struct
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* @master: SPI master
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* @dir: DMA transfer direction
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*
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* Function configures the DMA, maps the buffer and prepares the DMA
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@ -352,9 +256,11 @@ static void ep93xx_spi_pio_transfer(struct ep93xx_spi *espi)
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* in case of failure.
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*/
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static struct dma_async_tx_descriptor *
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ep93xx_spi_dma_prepare(struct ep93xx_spi *espi, enum dma_transfer_direction dir)
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ep93xx_spi_dma_prepare(struct spi_master *master,
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enum dma_transfer_direction dir)
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{
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struct spi_transfer *t = espi->current_msg->state;
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struct ep93xx_spi *espi = spi_master_get_devdata(master);
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struct spi_transfer *xfer = master->cur_msg->state;
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struct dma_async_tx_descriptor *txd;
|
|
|
|
|
enum dma_slave_buswidth buswidth;
|
|
|
|
|
struct dma_slave_config conf;
|
|
|
|
@ -362,10 +268,10 @@ ep93xx_spi_dma_prepare(struct ep93xx_spi *espi, enum dma_transfer_direction dir)
|
|
|
|
|
struct sg_table *sgt;
|
|
|
|
|
struct dma_chan *chan;
|
|
|
|
|
const void *buf, *pbuf;
|
|
|
|
|
size_t len = t->len;
|
|
|
|
|
size_t len = xfer->len;
|
|
|
|
|
int i, ret, nents;
|
|
|
|
|
|
|
|
|
|
if (t->bits_per_word > 8)
|
|
|
|
|
if (xfer->bits_per_word > 8)
|
|
|
|
|
buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
|
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|
|
|
else
|
|
|
|
|
buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
|
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|
|
@ -375,14 +281,14 @@ ep93xx_spi_dma_prepare(struct ep93xx_spi *espi, enum dma_transfer_direction dir)
|
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|
|
|
|
|
|
|
if (dir == DMA_DEV_TO_MEM) {
|
|
|
|
|
chan = espi->dma_rx;
|
|
|
|
|
buf = t->rx_buf;
|
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|
|
buf = xfer->rx_buf;
|
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|
|
sgt = &espi->rx_sgt;
|
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|
|
conf.src_addr = espi->sspdr_phys;
|
|
|
|
|
conf.src_addr_width = buswidth;
|
|
|
|
|
} else {
|
|
|
|
|
chan = espi->dma_tx;
|
|
|
|
|
buf = t->tx_buf;
|
|
|
|
|
buf = xfer->tx_buf;
|
|
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|
|
sgt = &espi->tx_sgt;
|
|
|
|
|
|
|
|
|
|
conf.dst_addr = espi->sspdr_phys;
|
|
|
|
@ -429,7 +335,7 @@ ep93xx_spi_dma_prepare(struct ep93xx_spi *espi, enum dma_transfer_direction dir)
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (WARN_ON(len)) {
|
|
|
|
|
dev_warn(&espi->pdev->dev, "len = %zu expected 0!\n", len);
|
|
|
|
|
dev_warn(&master->dev, "len = %zu expected 0!\n", len);
|
|
|
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
@ -447,15 +353,16 @@ ep93xx_spi_dma_prepare(struct ep93xx_spi *espi, enum dma_transfer_direction dir)
|
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|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* ep93xx_spi_dma_finish() - finishes with a DMA transfer
|
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|
|
|
* @espi: ep93xx SPI controller struct
|
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|
|
|
* @master: SPI master
|
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|
|
|
* @dir: DMA transfer direction
|
|
|
|
|
*
|
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|
|
|
* Function finishes with the DMA transfer. After this, the DMA buffer is
|
|
|
|
|
* unmapped.
|
|
|
|
|
*/
|
|
|
|
|
static void ep93xx_spi_dma_finish(struct ep93xx_spi *espi,
|
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|
|
|
static void ep93xx_spi_dma_finish(struct spi_master *master,
|
|
|
|
|
enum dma_transfer_direction dir)
|
|
|
|
|
{
|
|
|
|
|
struct ep93xx_spi *espi = spi_master_get_devdata(master);
|
|
|
|
|
struct dma_chan *chan;
|
|
|
|
|
struct sg_table *sgt;
|
|
|
|
|
|
|
|
|
@ -472,223 +379,69 @@ static void ep93xx_spi_dma_finish(struct ep93xx_spi *espi,
|
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|
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|
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|
|
static void ep93xx_spi_dma_callback(void *callback_param)
|
|
|
|
|
{
|
|
|
|
|
complete(callback_param);
|
|
|
|
|
struct spi_master *master = callback_param;
|
|
|
|
|
|
|
|
|
|
ep93xx_spi_dma_finish(master, DMA_MEM_TO_DEV);
|
|
|
|
|
ep93xx_spi_dma_finish(master, DMA_DEV_TO_MEM);
|
|
|
|
|
|
|
|
|
|
spi_finalize_current_transfer(master);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void ep93xx_spi_dma_transfer(struct ep93xx_spi *espi)
|
|
|
|
|
static int ep93xx_spi_dma_transfer(struct spi_master *master)
|
|
|
|
|
{
|
|
|
|
|
struct spi_message *msg = espi->current_msg;
|
|
|
|
|
struct ep93xx_spi *espi = spi_master_get_devdata(master);
|
|
|
|
|
struct dma_async_tx_descriptor *rxd, *txd;
|
|
|
|
|
|
|
|
|
|
rxd = ep93xx_spi_dma_prepare(espi, DMA_DEV_TO_MEM);
|
|
|
|
|
rxd = ep93xx_spi_dma_prepare(master, DMA_DEV_TO_MEM);
|
|
|
|
|
if (IS_ERR(rxd)) {
|
|
|
|
|
dev_err(&espi->pdev->dev, "DMA RX failed: %ld\n", PTR_ERR(rxd));
|
|
|
|
|
msg->status = PTR_ERR(rxd);
|
|
|
|
|
return;
|
|
|
|
|
dev_err(&master->dev, "DMA RX failed: %ld\n", PTR_ERR(rxd));
|
|
|
|
|
return PTR_ERR(rxd);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
txd = ep93xx_spi_dma_prepare(espi, DMA_MEM_TO_DEV);
|
|
|
|
|
txd = ep93xx_spi_dma_prepare(master, DMA_MEM_TO_DEV);
|
|
|
|
|
if (IS_ERR(txd)) {
|
|
|
|
|
ep93xx_spi_dma_finish(espi, DMA_DEV_TO_MEM);
|
|
|
|
|
dev_err(&espi->pdev->dev, "DMA TX failed: %ld\n", PTR_ERR(txd));
|
|
|
|
|
msg->status = PTR_ERR(txd);
|
|
|
|
|
return;
|
|
|
|
|
ep93xx_spi_dma_finish(master, DMA_DEV_TO_MEM);
|
|
|
|
|
dev_err(&master->dev, "DMA TX failed: %ld\n", PTR_ERR(txd));
|
|
|
|
|
return PTR_ERR(txd);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* We are ready when RX is done */
|
|
|
|
|
rxd->callback = ep93xx_spi_dma_callback;
|
|
|
|
|
rxd->callback_param = &espi->wait;
|
|
|
|
|
rxd->callback_param = master;
|
|
|
|
|
|
|
|
|
|
/* Now submit both descriptors and wait while they finish */
|
|
|
|
|
/* Now submit both descriptors and start DMA */
|
|
|
|
|
dmaengine_submit(rxd);
|
|
|
|
|
dmaengine_submit(txd);
|
|
|
|
|
|
|
|
|
|
dma_async_issue_pending(espi->dma_rx);
|
|
|
|
|
dma_async_issue_pending(espi->dma_tx);
|
|
|
|
|
|
|
|
|
|
wait_for_completion(&espi->wait);
|
|
|
|
|
|
|
|
|
|
ep93xx_spi_dma_finish(espi, DMA_MEM_TO_DEV);
|
|
|
|
|
ep93xx_spi_dma_finish(espi, DMA_DEV_TO_MEM);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* ep93xx_spi_process_transfer() - processes one SPI transfer
|
|
|
|
|
* @espi: ep93xx SPI controller struct
|
|
|
|
|
* @msg: current message
|
|
|
|
|
* @t: transfer to process
|
|
|
|
|
*
|
|
|
|
|
* This function processes one SPI transfer given in @t. Function waits until
|
|
|
|
|
* transfer is complete (may sleep) and updates @msg->status based on whether
|
|
|
|
|
* transfer was successfully processed or not.
|
|
|
|
|
*/
|
|
|
|
|
static void ep93xx_spi_process_transfer(struct ep93xx_spi *espi,
|
|
|
|
|
struct spi_message *msg,
|
|
|
|
|
struct spi_transfer *t)
|
|
|
|
|
{
|
|
|
|
|
int err;
|
|
|
|
|
|
|
|
|
|
msg->state = t;
|
|
|
|
|
|
|
|
|
|
err = ep93xx_spi_chip_setup(espi, msg->spi, t);
|
|
|
|
|
if (err) {
|
|
|
|
|
dev_err(&espi->pdev->dev,
|
|
|
|
|
"failed to setup chip for transfer\n");
|
|
|
|
|
msg->status = err;
|
|
|
|
|
return;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
espi->rx = 0;
|
|
|
|
|
espi->tx = 0;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* There is no point of setting up DMA for the transfers which will
|
|
|
|
|
* fit into the FIFO and can be transferred with a single interrupt.
|
|
|
|
|
* So in these cases we will be using PIO and don't bother for DMA.
|
|
|
|
|
*/
|
|
|
|
|
if (espi->dma_rx && t->len > SPI_FIFO_SIZE)
|
|
|
|
|
ep93xx_spi_dma_transfer(espi);
|
|
|
|
|
else
|
|
|
|
|
ep93xx_spi_pio_transfer(espi);
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* In case of error during transmit, we bail out from processing
|
|
|
|
|
* the message.
|
|
|
|
|
*/
|
|
|
|
|
if (msg->status)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
msg->actual_length += t->len;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* After this transfer is finished, perform any possible
|
|
|
|
|
* post-transfer actions requested by the protocol driver.
|
|
|
|
|
*/
|
|
|
|
|
if (t->delay_usecs) {
|
|
|
|
|
set_current_state(TASK_UNINTERRUPTIBLE);
|
|
|
|
|
schedule_timeout(usecs_to_jiffies(t->delay_usecs));
|
|
|
|
|
}
|
|
|
|
|
if (t->cs_change) {
|
|
|
|
|
if (!list_is_last(&t->transfer_list, &msg->transfers)) {
|
|
|
|
|
/*
|
|
|
|
|
* In case protocol driver is asking us to drop the
|
|
|
|
|
* chipselect briefly, we let the scheduler to handle
|
|
|
|
|
* any "delay" here.
|
|
|
|
|
*/
|
|
|
|
|
ep93xx_spi_cs_control(msg->spi, false);
|
|
|
|
|
cond_resched();
|
|
|
|
|
ep93xx_spi_cs_control(msg->spi, true);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* ep93xx_spi_process_message() - process one SPI message
|
|
|
|
|
* @espi: ep93xx SPI controller struct
|
|
|
|
|
* @msg: message to process
|
|
|
|
|
*
|
|
|
|
|
* This function processes a single SPI message. We go through all transfers in
|
|
|
|
|
* the message and pass them to ep93xx_spi_process_transfer(). Chipselect is
|
|
|
|
|
* asserted during the whole message (unless per transfer cs_change is set).
|
|
|
|
|
*
|
|
|
|
|
* @msg->status contains %0 in case of success or negative error code in case of
|
|
|
|
|
* failure.
|
|
|
|
|
*/
|
|
|
|
|
static void ep93xx_spi_process_message(struct ep93xx_spi *espi,
|
|
|
|
|
struct spi_message *msg)
|
|
|
|
|
{
|
|
|
|
|
unsigned long timeout;
|
|
|
|
|
struct spi_transfer *t;
|
|
|
|
|
int err;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Enable the SPI controller and its clock.
|
|
|
|
|
*/
|
|
|
|
|
err = ep93xx_spi_enable(espi);
|
|
|
|
|
if (err) {
|
|
|
|
|
dev_err(&espi->pdev->dev, "failed to enable SPI controller\n");
|
|
|
|
|
msg->status = err;
|
|
|
|
|
return;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Just to be sure: flush any data from RX FIFO.
|
|
|
|
|
*/
|
|
|
|
|
timeout = jiffies + msecs_to_jiffies(SPI_TIMEOUT);
|
|
|
|
|
while (ep93xx_spi_read_u16(espi, SSPSR) & SSPSR_RNE) {
|
|
|
|
|
if (time_after(jiffies, timeout)) {
|
|
|
|
|
dev_warn(&espi->pdev->dev,
|
|
|
|
|
"timeout while flushing RX FIFO\n");
|
|
|
|
|
msg->status = -ETIMEDOUT;
|
|
|
|
|
return;
|
|
|
|
|
}
|
|
|
|
|
ep93xx_spi_read_u16(espi, SSPDR);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* We explicitly handle FIFO level. This way we don't have to check TX
|
|
|
|
|
* FIFO status using %SSPSR_TNF bit which may cause RX FIFO overruns.
|
|
|
|
|
*/
|
|
|
|
|
espi->fifo_level = 0;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Assert the chipselect.
|
|
|
|
|
*/
|
|
|
|
|
ep93xx_spi_cs_control(msg->spi, true);
|
|
|
|
|
|
|
|
|
|
list_for_each_entry(t, &msg->transfers, transfer_list) {
|
|
|
|
|
ep93xx_spi_process_transfer(espi, msg, t);
|
|
|
|
|
if (msg->status)
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Now the whole message is transferred (or failed for some reason). We
|
|
|
|
|
* deselect the device and disable the SPI controller.
|
|
|
|
|
*/
|
|
|
|
|
ep93xx_spi_cs_control(msg->spi, false);
|
|
|
|
|
ep93xx_spi_disable(espi);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int ep93xx_spi_transfer_one_message(struct spi_master *master,
|
|
|
|
|
struct spi_message *msg)
|
|
|
|
|
{
|
|
|
|
|
struct ep93xx_spi *espi = spi_master_get_devdata(master);
|
|
|
|
|
|
|
|
|
|
msg->state = NULL;
|
|
|
|
|
msg->status = 0;
|
|
|
|
|
msg->actual_length = 0;
|
|
|
|
|
|
|
|
|
|
espi->current_msg = msg;
|
|
|
|
|
ep93xx_spi_process_message(espi, msg);
|
|
|
|
|
espi->current_msg = NULL;
|
|
|
|
|
|
|
|
|
|
spi_finalize_current_message(master);
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
/* signal that we need to wait for completion */
|
|
|
|
|
return 1;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static irqreturn_t ep93xx_spi_interrupt(int irq, void *dev_id)
|
|
|
|
|
{
|
|
|
|
|
struct ep93xx_spi *espi = dev_id;
|
|
|
|
|
u8 irq_status = ep93xx_spi_read_u8(espi, SSPIIR);
|
|
|
|
|
struct spi_master *master = dev_id;
|
|
|
|
|
struct ep93xx_spi *espi = spi_master_get_devdata(master);
|
|
|
|
|
u32 val;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* If we got ROR (receive overrun) interrupt we know that something is
|
|
|
|
|
* wrong. Just abort the message.
|
|
|
|
|
*/
|
|
|
|
|
if (unlikely(irq_status & SSPIIR_RORIS)) {
|
|
|
|
|
if (readl(espi->mmio + SSPIIR) & SSPIIR_RORIS) {
|
|
|
|
|
/* clear the overrun interrupt */
|
|
|
|
|
ep93xx_spi_write_u8(espi, SSPICR, 0);
|
|
|
|
|
dev_warn(&espi->pdev->dev,
|
|
|
|
|
writel(0, espi->mmio + SSPICR);
|
|
|
|
|
dev_warn(&master->dev,
|
|
|
|
|
"receive overrun, aborting the message\n");
|
|
|
|
|
espi->current_msg->status = -EIO;
|
|
|
|
|
master->cur_msg->status = -EIO;
|
|
|
|
|
} else {
|
|
|
|
|
/*
|
|
|
|
|
* Interrupt is either RX (RIS) or TX (TIS). For both cases we
|
|
|
|
|
* simply execute next data transfer.
|
|
|
|
|
*/
|
|
|
|
|
if (ep93xx_spi_read_write(espi)) {
|
|
|
|
|
if (ep93xx_spi_read_write(master)) {
|
|
|
|
|
/*
|
|
|
|
|
* In normal case, there still is some processing left
|
|
|
|
|
* for current transfer. Let's wait for the next
|
|
|
|
@ -703,11 +456,111 @@ static irqreturn_t ep93xx_spi_interrupt(int irq, void *dev_id)
|
|
|
|
|
* any case we disable interrupts and notify the worker to handle
|
|
|
|
|
* any post-processing of the message.
|
|
|
|
|
*/
|
|
|
|
|
ep93xx_spi_disable_interrupts(espi);
|
|
|
|
|
complete(&espi->wait);
|
|
|
|
|
val = readl(espi->mmio + SSPCR1);
|
|
|
|
|
val &= ~(SSPCR1_RORIE | SSPCR1_TIE | SSPCR1_RIE);
|
|
|
|
|
writel(val, espi->mmio + SSPCR1);
|
|
|
|
|
|
|
|
|
|
spi_finalize_current_transfer(master);
|
|
|
|
|
|
|
|
|
|
return IRQ_HANDLED;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int ep93xx_spi_transfer_one(struct spi_master *master,
|
|
|
|
|
struct spi_device *spi,
|
|
|
|
|
struct spi_transfer *xfer)
|
|
|
|
|
{
|
|
|
|
|
struct ep93xx_spi *espi = spi_master_get_devdata(master);
|
|
|
|
|
u32 val;
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
ret = ep93xx_spi_chip_setup(master, spi, xfer);
|
|
|
|
|
if (ret) {
|
|
|
|
|
dev_err(&master->dev, "failed to setup chip for transfer\n");
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
master->cur_msg->state = xfer;
|
|
|
|
|
espi->rx = 0;
|
|
|
|
|
espi->tx = 0;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* There is no point of setting up DMA for the transfers which will
|
|
|
|
|
* fit into the FIFO and can be transferred with a single interrupt.
|
|
|
|
|
* So in these cases we will be using PIO and don't bother for DMA.
|
|
|
|
|
*/
|
|
|
|
|
if (espi->dma_rx && xfer->len > SPI_FIFO_SIZE)
|
|
|
|
|
return ep93xx_spi_dma_transfer(master);
|
|
|
|
|
|
|
|
|
|
/* Using PIO so prime the TX FIFO and enable interrupts */
|
|
|
|
|
ep93xx_spi_read_write(master);
|
|
|
|
|
|
|
|
|
|
val = readl(espi->mmio + SSPCR1);
|
|
|
|
|
val |= (SSPCR1_RORIE | SSPCR1_TIE | SSPCR1_RIE);
|
|
|
|
|
writel(val, espi->mmio + SSPCR1);
|
|
|
|
|
|
|
|
|
|
/* signal that we need to wait for completion */
|
|
|
|
|
return 1;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int ep93xx_spi_prepare_message(struct spi_master *master,
|
|
|
|
|
struct spi_message *msg)
|
|
|
|
|
{
|
|
|
|
|
struct ep93xx_spi *espi = spi_master_get_devdata(master);
|
|
|
|
|
unsigned long timeout;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Just to be sure: flush any data from RX FIFO.
|
|
|
|
|
*/
|
|
|
|
|
timeout = jiffies + msecs_to_jiffies(SPI_TIMEOUT);
|
|
|
|
|
while (readl(espi->mmio + SSPSR) & SSPSR_RNE) {
|
|
|
|
|
if (time_after(jiffies, timeout)) {
|
|
|
|
|
dev_warn(&master->dev,
|
|
|
|
|
"timeout while flushing RX FIFO\n");
|
|
|
|
|
return -ETIMEDOUT;
|
|
|
|
|
}
|
|
|
|
|
readl(espi->mmio + SSPDR);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* We explicitly handle FIFO level. This way we don't have to check TX
|
|
|
|
|
* FIFO status using %SSPSR_TNF bit which may cause RX FIFO overruns.
|
|
|
|
|
*/
|
|
|
|
|
espi->fifo_level = 0;
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int ep93xx_spi_prepare_hardware(struct spi_master *master)
|
|
|
|
|
{
|
|
|
|
|
struct ep93xx_spi *espi = spi_master_get_devdata(master);
|
|
|
|
|
u32 val;
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
ret = clk_enable(espi->clk);
|
|
|
|
|
if (ret)
|
|
|
|
|
return ret;
|
|
|
|
|
|
|
|
|
|
val = readl(espi->mmio + SSPCR1);
|
|
|
|
|
val |= SSPCR1_SSE;
|
|
|
|
|
writel(val, espi->mmio + SSPCR1);
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int ep93xx_spi_unprepare_hardware(struct spi_master *master)
|
|
|
|
|
{
|
|
|
|
|
struct ep93xx_spi *espi = spi_master_get_devdata(master);
|
|
|
|
|
u32 val;
|
|
|
|
|
|
|
|
|
|
val = readl(espi->mmio + SSPCR1);
|
|
|
|
|
val &= ~SSPCR1_SSE;
|
|
|
|
|
writel(val, espi->mmio + SSPCR1);
|
|
|
|
|
|
|
|
|
|
clk_disable(espi->clk);
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool ep93xx_spi_dma_filter(struct dma_chan *chan, void *filter_param)
|
|
|
|
|
{
|
|
|
|
|
if (ep93xx_dma_chan_is_m2p(chan))
|
|
|
|
@ -809,7 +662,10 @@ static int ep93xx_spi_probe(struct platform_device *pdev)
|
|
|
|
|
if (!master)
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
|
|
master->transfer_one_message = ep93xx_spi_transfer_one_message;
|
|
|
|
|
master->prepare_transfer_hardware = ep93xx_spi_prepare_hardware;
|
|
|
|
|
master->unprepare_transfer_hardware = ep93xx_spi_unprepare_hardware;
|
|
|
|
|
master->prepare_message = ep93xx_spi_prepare_message;
|
|
|
|
|
master->transfer_one = ep93xx_spi_transfer_one;
|
|
|
|
|
master->bus_num = pdev->id;
|
|
|
|
|
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
|
|
|
|
|
master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
|
|
|
|
@ -850,26 +706,23 @@ static int ep93xx_spi_probe(struct platform_device *pdev)
|
|
|
|
|
goto fail_release_master;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
init_completion(&espi->wait);
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Calculate maximum and minimum supported clock rates
|
|
|
|
|
* for the controller.
|
|
|
|
|
*/
|
|
|
|
|
master->max_speed_hz = clk_get_rate(espi->clk) / 2;
|
|
|
|
|
master->min_speed_hz = clk_get_rate(espi->clk) / (254 * 256);
|
|
|
|
|
espi->pdev = pdev;
|
|
|
|
|
|
|
|
|
|
espi->sspdr_phys = res->start + SSPDR;
|
|
|
|
|
|
|
|
|
|
espi->regs_base = devm_ioremap_resource(&pdev->dev, res);
|
|
|
|
|
if (IS_ERR(espi->regs_base)) {
|
|
|
|
|
error = PTR_ERR(espi->regs_base);
|
|
|
|
|
espi->mmio = devm_ioremap_resource(&pdev->dev, res);
|
|
|
|
|
if (IS_ERR(espi->mmio)) {
|
|
|
|
|
error = PTR_ERR(espi->mmio);
|
|
|
|
|
goto fail_release_master;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
error = devm_request_irq(&pdev->dev, irq, ep93xx_spi_interrupt,
|
|
|
|
|
0, "ep93xx-spi", espi);
|
|
|
|
|
0, "ep93xx-spi", master);
|
|
|
|
|
if (error) {
|
|
|
|
|
dev_err(&pdev->dev, "failed to request irq\n");
|
|
|
|
|
goto fail_release_master;
|
|
|
|
@ -879,7 +732,7 @@ static int ep93xx_spi_probe(struct platform_device *pdev)
|
|
|
|
|
dev_warn(&pdev->dev, "DMA setup failed. Falling back to PIO\n");
|
|
|
|
|
|
|
|
|
|
/* make sure that the hardware is disabled */
|
|
|
|
|
ep93xx_spi_write_u8(espi, SSPCR1, 0);
|
|
|
|
|
writel(0, espi->mmio + SSPCR1);
|
|
|
|
|
|
|
|
|
|
error = devm_spi_register_master(&pdev->dev, master);
|
|
|
|
|
if (error) {
|
|
|
|
|