From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-ww0-f49.google.com ([74.125.82.49]) by canuck.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QnFzV-0006Ig-JH for barebox@lists.infradead.org; Sat, 30 Jul 2011 20:18:34 +0000 Received: by wwf22 with SMTP id 22so3169435wwf.18 for ; Sat, 30 Jul 2011 13:18:29 -0700 (PDT) From: franck.jullien@gmail.com Date: Sat, 30 Jul 2011 22:18:23 +0200 Message-Id: <1312057103-29658-1-git-send-email-franck.jullien@gmail.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: barebox-bounces@lists.infradead.org Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH] nios2: Add Altera SPI master driver To: barebox@lists.infradead.org From: Franck Jullien Signed-off-by: Franck Jullien --- arch/nios2/include/asm/spi.h | 21 ++++ drivers/spi/Kconfig | 5 + drivers/spi/Makefile | 1 + drivers/spi/altera_spi.c | 226 ++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 253 insertions(+), 0 deletions(-) create mode 100644 arch/nios2/include/asm/spi.h create mode 100644 drivers/spi/altera_spi.c diff --git a/arch/nios2/include/asm/spi.h b/arch/nios2/include/asm/spi.h new file mode 100644 index 0000000..4e576b9 --- /dev/null +++ b/arch/nios2/include/asm/spi.h @@ -0,0 +1,21 @@ +#ifndef __ALTERA_SPI_H_ +#define __ALTERA_SPI_H_ + +#include + +struct spi_altera_master { + int num_chipselect; + int spi_mode; + int databits; + int speed; +}; + +struct altera_spi { + struct spi_master master; + int databits; + int speed; + int mode; + void __iomem *regs; +}; + +#endif /*__ALTERA_SPI_H_*/ diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 9ab03f6..c72493c 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -19,4 +19,9 @@ config DRIVER_SPI_IMX_2_3 depends on ARCH_IMX51 || ARCH_IMX53 default y +config DRIVER_SPI_ALTERA + bool "Altera SPI Master driver" + depends on NIOS2 + depends on SPI + endmenu diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index b2b2f67..90e141d 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -1,2 +1,3 @@ obj-$(CONFIG_SPI) += spi.o obj-$(CONFIG_DRIVER_SPI_IMX) += imx_spi.o +obj-$(CONFIG_DRIVER_SPI_ALTERA) += altera_spi.o diff --git a/drivers/spi/altera_spi.c b/drivers/spi/altera_spi.c new file mode 100644 index 0000000..71df6b7 --- /dev/null +++ b/drivers/spi/altera_spi.c @@ -0,0 +1,226 @@ +/* + * (C) Copyright 2011 - Franck JULLIEN + * Inspired from Thomas Chou's Linux spi_altera.c driver + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + * + */ + +#include +#include +#include +#include +#include +#include +#include + +#define CS_ACTIVE 1 +#define CS_INACTIVE 0 + +static int altera_spi_setup(struct spi_device *spi) +{ + struct spi_master *master = spi->master; + struct device_d *master_dev = master->dev; + struct device_d spi_dev = spi->dev; + struct altera_spi *altera_spi = container_of(master, struct altera_spi, master); + + if (spi->bits_per_word != altera_spi->databits) { + printf("%s doesn't support %d bits per word requested by %s\n", master_dev->name, + spi->bits_per_word, spi_dev.name); + return -1; + } + + if ((spi->mode & (SPI_CPHA | SPI_CPOL)) != altera_spi->mode) { + printf("%s doesn't support SPI_MODE%d requested by %s\n", master_dev->name, + spi->mode & (SPI_CPHA | SPI_CPOL), spi_dev.name); + return -1; + } + + if (spi->max_speed_hz < altera_spi->speed) { + printf("%s frequency is too high for %s\n", master_dev->name, spi_dev.name); + return -1; + } + + debug("%s mode 0x%08x bits_per_word: %d speed: %d\n", + __func__, spi->mode, spi->bits_per_word, + altera_spi->speed); + + return 0; +} + + +static unsigned int altera_spi_xchg_single(struct altera_spi *altera_spi, unsigned int data) +{ + struct nios_spi *nios_spi = altera_spi->regs; + + while (!(readl(&nios_spi->status) & NIOS_SPI_TRDY)); + writel(data, &nios_spi->txdata); + + while (!(readl(&nios_spi->status) & NIOS_SPI_RRDY)); + + return readl(&nios_spi->rxdata); +} + +/* + * When using SPI_CS_HIGH devices, only one device is allowed to be + * connected to the Altera SPI master. This limitation is due to the + * emulation of an active high CS by writing 0 to the slaveselect register + * (this produce a '1' to all CS pins). + */ +static void altera_spi_chipselect(struct spi_device *spi, int is_active) +{ + struct altera_spi *altera_spi = container_of(spi->master, struct altera_spi, master); + struct nios_spi *nios_spi = altera_spi->regs; + uint32_t tmp; + + if (spi->mode & SPI_CS_HIGH) { + switch (is_active) { + case CS_INACTIVE: + writel(1 << spi->chip_select, &nios_spi->slaveselect); + tmp = readl(&nios_spi->control); + writel(tmp | NIOS_SPI_SSO, &nios_spi->control); + break; + + case CS_ACTIVE: + tmp = readw(&nios_spi->control); + writew(tmp & ~NIOS_SPI_SSO, &nios_spi->control); + writel(0, &nios_spi->slaveselect); + break; + } + } else { + switch (is_active) { + case CS_INACTIVE: + tmp = readw(&nios_spi->control); + writew(tmp & ~NIOS_SPI_SSO, &nios_spi->control); + break; + + case CS_ACTIVE: + writel(1 << spi->chip_select, &nios_spi->slaveselect); + tmp = readl(&nios_spi->control); + writel(tmp | NIOS_SPI_SSO, &nios_spi->control); + break; + } + } +} + +static int altera_spi_transfer(struct spi_device *spi, struct spi_message *mesg) +{ + struct altera_spi *altera_spi = container_of(spi->master, struct altera_spi, master); + struct nios_spi *nios_spi = altera_spi->regs; + struct spi_transfer *t = NULL; + int word_len = spi->bits_per_word; + + u32 txval; + u32 rxval; + + altera_spi_chipselect(spi, 1); + + word_len = spi->bits_per_word; + mesg->actual_length = 0; + + list_for_each_entry(t, &mesg->transfers, transfer_list) { + + if (word_len <= 8) { + const u8 *txbuf = t->tx_buf; + u8 *rxbuf = t->rx_buf; + int i = 0; + + while (i < t->len) { + txval = txbuf ? txbuf[i] : 0; + rxval = altera_spi_xchg_single(altera_spi, txval); + if (rxbuf) + rxbuf[i] = rxval; + i++; + mesg->actual_length++; + } + } else if (word_len <= 16) { + const u16 *txbuf = t->tx_buf; + u16 *rxbuf = t->rx_buf; + int i = 0; + + while (i < t->len >> 1) { + txval = txbuf ? txbuf[i] : 0; + rxval = altera_spi_xchg_single(altera_spi, txval); + if (rxbuf) + rxbuf[i] = rxval; + i++; + mesg->actual_length += 2; + } + } else if (word_len <= 32) { + const u32 *txbuf = t->tx_buf; + u32 *rxbuf = t->rx_buf; + int i = 0; + + while (i < t->len >> 2) { + txval = txbuf ? txbuf[i] : 0; + rxval = altera_spi_xchg_single(altera_spi, txval); + if (rxbuf) + rxbuf[i] = rxval; + i++; + mesg->actual_length += 4; + } + } + } + + /* Wait the end of any pending transfert */ + while ((readl(&nios_spi->status) & NIOS_SPI_TMT) == 0); + + altera_spi_chipselect(spi, 0); + + return 0; +} + +static int altera_spi_probe(struct device_d *dev) +{ + struct spi_master *master; + struct altera_spi *altera_spi; + struct spi_altera_master *pdata = dev->platform_data; + struct nios_spi *nios_spi; + + altera_spi = xzalloc(sizeof(*altera_spi)); + + master = &altera_spi->master; + master->dev = dev; + + master->setup = altera_spi_setup; + master->transfer = altera_spi_transfer; + master->num_chipselect = pdata->num_chipselect; + + altera_spi->regs = dev_request_mem_region(dev, 0); + altera_spi->databits = pdata->databits; + altera_spi->speed = pdata->speed; + altera_spi->mode = pdata->spi_mode; + + nios_spi = altera_spi->regs; + writel(0, &nios_spi->slaveselect); + writel(0, &nios_spi->control); + + spi_register_master(master); + + return 0; +} + +static struct driver_d altera_spi_driver = { + .name = "altera_spi", + .probe = altera_spi_probe, +}; + +static int altera_spi_driver_init(void) +{ + return register_driver(&altera_spi_driver); +} + +device_initcall(altera_spi_driver_init); -- 1.7.6 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox