[PATCH v2] spi: atmel: improve internal vs gpio chip-select choice
From: Mans Rullgard <hidden>
Date: 2016-01-11 16:02:26
The driver currently chooses between internal chip-select or gpio based on the existence of the cs-gpios DT property which fails on non-DT systems and also enforces the same choice for all devices. This patch makes the method per device instead of per controller and fixes the selection on non-DT systems. With these changes, the chip-select method for each device is chosen according to the following priority: 1. GPIO from device tree 2. GPIO from platform data 3. Internal chip-select Tested on AVR32 ATSTK1000. Signed-off-by: Mans Rullgard <redacted> --- Changes: - allow internal CS only hardware v2 - retain seting of master->num_chipselect to 4 on hardware v2 if cs-gpios property is missing --- drivers/spi/spi-atmel.c | 38 +++++++++++++++++++++++--------------- 1 file changed, 23 insertions(+), 15 deletions(-)
diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 08cbb3e43c76..d4a806e24060 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c@@ -312,7 +312,6 @@ struct atmel_spi { bool use_dma; bool use_pdc; - bool use_cs_gpios; /* dmaengine data */ struct atmel_spi_dma dma;
@@ -323,6 +322,7 @@ struct atmel_spi { struct atmel_spi_device { unsigned int npcs_pin; u32 csr; + bool use_cs_gpio; }; #define BUFFER_SIZE PAGE_SIZE
@@ -387,7 +387,7 @@ static void cs_activate(struct atmel_spi *as, struct spi_device *spi) } mr = spi_readl(as, MR); - if (as->use_cs_gpios) + if (asd->use_cs_gpio) gpio_set_value(asd->npcs_pin, active); } else { u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0;
@@ -404,7 +404,7 @@ static void cs_activate(struct atmel_spi *as, struct spi_device *spi) mr = spi_readl(as, MR); mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr); - if (as->use_cs_gpios && spi->chip_select != 0) + if (asd->use_cs_gpio && spi->chip_select != 0) gpio_set_value(asd->npcs_pin, active); spi_writel(as, MR, mr); }
@@ -433,7 +433,7 @@ static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi) asd->npcs_pin, active ? " (low)" : "", mr); - if (!as->use_cs_gpios) + if (!asd->use_cs_gpio) spi_writel(as, CR, SPI_BIT(LASTXFER)); else if (atmel_spi_is_v2(as) || spi->chip_select != 0) gpio_set_value(asd->npcs_pin, !active);
@@ -1539,6 +1539,7 @@ static int atmel_spi_setup(struct spi_device *spi) unsigned int bits = spi->bits_per_word; unsigned int npcs_pin; int ret; + bool use_cs_gpio; as = spi_master_get_devdata(spi->master);
@@ -1565,8 +1566,6 @@ static int atmel_spi_setup(struct spi_device *spi) csr |= SPI_BIT(CPOL); if (!(spi->mode & SPI_CPHA)) csr |= SPI_BIT(NCPHA); - if (!as->use_cs_gpios) - csr |= SPI_BIT(CSAAT); /* DLYBS is mostly irrelevant since we manage chipselect using GPIOs. *
@@ -1577,13 +1576,22 @@ static int atmel_spi_setup(struct spi_device *spi) csr |= SPI_BF(DLYBS, 0); csr |= SPI_BF(DLYBCT, 0); - /* chipselect must have been muxed as GPIO (e.g. in board setup) */ npcs_pin = (unsigned long)spi->controller_data; - if (!as->use_cs_gpios) - npcs_pin = spi->chip_select; - else if (gpio_is_valid(spi->cs_gpio)) + if (gpio_is_valid(spi->cs_gpio)) { + /* GPIO from DT */ npcs_pin = spi->cs_gpio; + use_cs_gpio = true; + } else if (npcs_pin && gpio_is_valid(npcs_pin)) { + /* GPIO from platform data */ + use_cs_gpio = true; + } else if (atmel_spi_is_v2(as)) { + /* internal chip-select */ + npcs_pin = spi->chip_select; + use_cs_gpio = false; + } else { + return -EINVAL; + } asd = spi->controller_state; if (!asd) {
@@ -1591,7 +1599,7 @@ static int atmel_spi_setup(struct spi_device *spi) if (!asd) return -ENOMEM; - if (as->use_cs_gpios) { + if (use_cs_gpio) { ret = gpio_request(npcs_pin, dev_name(&spi->dev)); if (ret) { kfree(asd);
@@ -1603,6 +1611,7 @@ static int atmel_spi_setup(struct spi_device *spi) } asd->npcs_pin = npcs_pin; + asd->use_cs_gpio = use_cs_gpio; spi->controller_state = asd; } else { atmel_spi_lock(as);
@@ -1612,6 +1621,8 @@ static int atmel_spi_setup(struct spi_device *spi) atmel_spi_unlock(as); } + if (!asd->use_cs_gpio) + csr |= SPI_BIT(CSAAT); asd->csr = csr; dev_dbg(&spi->dev,
@@ -1807,12 +1818,9 @@ static int atmel_spi_probe(struct platform_device *pdev) atmel_get_caps(as); - as->use_cs_gpios = true; if (atmel_spi_is_v2(as) && - !of_get_property(pdev->dev.of_node, "cs-gpios", NULL)) { - as->use_cs_gpios = false; + !of_get_property(pdev->dev.of_node, "cs-gpios", NULL)) master->num_chipselect = 4; - } as->use_dma = false; as->use_pdc = false;
--
2.7.0