From: Lubomir Rintel Date: Tue, 13 Nov 2018 10:22:25 +0000 (+0100) Subject: spi: pxa2xx: Add slave mode support X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=ec93cb6f827b3e1a81b0721b8c893d2a5e37e7d6;p=openwrt%2Fstaging%2Fblogic.git spi: pxa2xx: Add slave mode support Tested on an OLPC XO-1.75 machine, where the Embedded Controller happens to be a SPI master. Signed-off-by: Lubomir Rintel Acked-by: Pavel Machek Signed-off-by: Mark Brown --- diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c index d46af116d630..a057c3be7e3b 100644 --- a/drivers/spi/spi-pxa2xx.c +++ b/drivers/spi/spi-pxa2xx.c @@ -626,6 +626,11 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data) return IRQ_HANDLED; } + if (irq_status & SSSR_TUR) { + int_error_stop(drv_data, "interrupt_transfer: fifo underrun"); + return IRQ_HANDLED; + } + if (irq_status & SSSR_TINT) { pxa2xx_spi_write(drv_data, SSSR, SSSR_TINT); if (drv_data->read(drv_data)) { @@ -1073,6 +1078,11 @@ static int pxa2xx_spi_transfer_one(struct spi_controller *master, pxa2xx_spi_write(drv_data, SSTO, chip->timeout); } + if (spi_controller_is_slave(master)) { + while (drv_data->write(drv_data)) + ; + } + /* * Release the data by enabling service requests and interrupts, * without changing any mode bits @@ -1082,6 +1092,27 @@ static int pxa2xx_spi_transfer_one(struct spi_controller *master, return 1; } +static int pxa2xx_spi_slave_abort(struct spi_master *master) +{ + struct driver_data *drv_data = spi_controller_get_devdata(master); + + /* Stop and reset SSP */ + write_SSSR_CS(drv_data, drv_data->clear_sr); + reset_sccr1(drv_data); + if (!pxa25x_ssp_comp(drv_data)) + pxa2xx_spi_write(drv_data, SSTO, 0); + pxa2xx_spi_flush(drv_data); + pxa2xx_spi_write(drv_data, SSCR0, + pxa2xx_spi_read(drv_data, SSCR0) & ~SSCR0_SSE); + + dev_dbg(&drv_data->pdev->dev, "transfer aborted\n"); + + drv_data->master->cur_msg->status = -EINTR; + spi_finalize_current_transfer(drv_data->master); + + return 0; +} + static void pxa2xx_spi_handle_err(struct spi_controller *master, struct spi_message *msg) { @@ -1209,9 +1240,14 @@ static int setup(struct spi_device *spi) rx_thres = config->rx_threshold; break; default: - tx_thres = TX_THRESH_DFLT; tx_hi_thres = 0; - rx_thres = RX_THRESH_DFLT; + if (spi_controller_is_slave(drv_data->master)) { + tx_thres = 1; + rx_thres = 2; + } else { + tx_thres = TX_THRESH_DFLT; + rx_thres = RX_THRESH_DFLT; + } break; } @@ -1255,6 +1291,12 @@ static int setup(struct spi_device *spi) if (chip_info->enable_loopback) chip->cr1 = SSCR1_LBM; } + if (spi_controller_is_slave(drv_data->master)) { + chip->cr1 |= SSCR1_SCFR; + chip->cr1 |= SSCR1_SCLKDIR; + chip->cr1 |= SSCR1_SFRMDIR; + chip->cr1 |= SSCR1_SPH; + } chip->lpss_rx_threshold = SSIRF_RxThresh(rx_thres); chip->lpss_tx_threshold = SSITF_TxLoThresh(tx_thres) @@ -1494,6 +1536,13 @@ pxa2xx_spi_init_pdata(struct platform_device *pdev) } #endif +#if CONFIG_OF + if (of_id) { + pdata->is_slave = of_property_read_bool(pdev->dev.of_node, + "spi-slave"); + } +#endif + ssp->clk = devm_clk_get(&pdev->dev, NULL); ssp->irq = platform_get_irq(pdev, 0); ssp->type = type; @@ -1559,7 +1608,11 @@ static int pxa2xx_spi_probe(struct platform_device *pdev) return -ENODEV; } - master = spi_alloc_master(dev, sizeof(struct driver_data)); + if (platform_info->is_slave) + master = spi_alloc_slave(dev, sizeof(struct driver_data)); + else + master = spi_alloc_master(dev, sizeof(struct driver_data)); + if (!master) { dev_err(&pdev->dev, "cannot alloc spi_master\n"); pxa_ssp_free(ssp); @@ -1581,6 +1634,7 @@ static int pxa2xx_spi_probe(struct platform_device *pdev) master->setup = setup; master->set_cs = pxa2xx_spi_set_cs; master->transfer_one = pxa2xx_spi_transfer_one; + master->slave_abort = pxa2xx_spi_slave_abort; master->handle_err = pxa2xx_spi_handle_err; master->unprepare_transfer_hardware = pxa2xx_spi_unprepare_transfer; master->fw_translate_cs = pxa2xx_spi_fw_translate_cs; @@ -1610,7 +1664,8 @@ static int pxa2xx_spi_probe(struct platform_device *pdev) drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE; drv_data->dma_cr1 = DEFAULT_DMA_CR1; drv_data->clear_sr = SSSR_ROR | SSSR_TINT; - drv_data->mask_sr = SSSR_TINT | SSSR_RFS | SSSR_TFS | SSSR_ROR; + drv_data->mask_sr = SSSR_TINT | SSSR_RFS | SSSR_TFS + | SSSR_ROR | SSSR_TUR; } status = request_irq(ssp->irq, ssp_int, IRQF_SHARED, dev_name(dev), @@ -1658,10 +1713,22 @@ static int pxa2xx_spi_probe(struct platform_device *pdev) pxa2xx_spi_write(drv_data, SSCR0, tmp); break; default: - tmp = SSCR1_RxTresh(RX_THRESH_DFLT) | - SSCR1_TxTresh(TX_THRESH_DFLT); + + if (spi_controller_is_slave(master)) { + tmp = SSCR1_SCFR | + SSCR1_SCLKDIR | + SSCR1_SFRMDIR | + SSCR1_RxTresh(2) | + SSCR1_TxTresh(1) | + SSCR1_SPH; + } else { + tmp = SSCR1_RxTresh(RX_THRESH_DFLT) | + SSCR1_TxTresh(TX_THRESH_DFLT); + } pxa2xx_spi_write(drv_data, SSCR1, tmp); - tmp = SSCR0_SCR(2) | SSCR0_Motorola | SSCR0_DataSize(8); + tmp = SSCR0_Motorola | SSCR0_DataSize(8); + if (!spi_controller_is_slave(master)) + tmp |= SSCR0_SCR(2); pxa2xx_spi_write(drv_data, SSCR0, tmp); break; } diff --git a/include/linux/spi/pxa2xx_spi.h b/include/linux/spi/pxa2xx_spi.h index 9ec4c147abbc..b0674e330ef6 100644 --- a/include/linux/spi/pxa2xx_spi.h +++ b/include/linux/spi/pxa2xx_spi.h @@ -25,6 +25,7 @@ struct dma_chan; struct pxa2xx_spi_master { u16 num_chipselect; u8 enable_dma; + bool is_slave; /* DMA engine specific config */ bool (*dma_filter)(struct dma_chan *chan, void *param);