Unverified Commit ec93cb6f authored by Lubomir Rintel's avatar Lubomir Rintel Committed by Mark Brown
Browse files

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: default avatarLubomir Rintel <lkundrak@v3.sk>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 810923f3

drivers/spi/spi-pxa2xx.c

+74 −7
Original line number Diff line number Diff line
@@ -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;

		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;

	}



	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:



		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;

	}

include/linux/spi/pxa2xx_spi.h

+1 −0
Original line number Diff line number Diff line
@@ -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);