Applied "spi: pxa2xx: Add slave mode support" to the spi tree
diff mbox series

Message ID 20181113183547.0F95D440078@finisterre.ee.mobilebroadband
State New, archived
Headers show
Series
  • Applied "spi: pxa2xx: Add slave mode support" to the spi tree
Related show

Commit Message

Mark Brown Nov. 13, 2018, 6:35 p.m. UTC
The patch

   spi: pxa2xx: Add slave mode support

has been applied to the spi tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

From ec93cb6f827b3e1a81b0721b8c893d2a5e37e7d6 Mon Sep 17 00:00:00 2001
From: Lubomir Rintel <lkundrak@v3.sk>
Date: Tue, 13 Nov 2018 11:22:25 +0100
Subject: [PATCH] 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 <lkundrak@v3.sk>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/spi/spi-pxa2xx.c       | 81 +++++++++++++++++++++++++++++++---
 include/linux/spi/pxa2xx_spi.h |  1 +
 2 files changed, 75 insertions(+), 7 deletions(-)

Patch
diff mbox series

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);