From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752940Ab1AQIFA (ORCPT ); Mon, 17 Jan 2011 03:05:00 -0500 Received: from mailout07.yourhostingaccount.com ([65.254.253.62]:34418 "EHLO mailout07.yourhostingaccount.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752526Ab1AQIE5 (ORCPT ); Mon, 17 Jan 2011 03:04:57 -0500 X-Greylist: delayed 2202 seconds by postgrey-1.27 at vger.kernel.org; Mon, 17 Jan 2011 03:04:57 EST X-EN-OrigOutIP: 10.1.18.4 X-EN-IMPSID: wXUC1f00105G96J0000000 Message-ID: <4D33EF7C.7030005@writeme.com> Date: Mon, 17 Jan 2011 02:27:56 -0500 From: Sinan Akman User-Agent: Thunderbird 2.0.0.24 (X11/20100324) MIME-Version: 1.0 To: Thomas Chou CC: David Brownell , Grant Likely , nios2-dev@sopc.et.ntust.edu.tw, Mike Frysinger , devicetree-discuss@lists.ozlabs.org, linux-kernel@vger.kernel.org, spi-devel-general@lists.sourceforge.net Subject: Re: [PATCH v3] spi: New driver for Altera SPI References: <1295247869-4968-1-git-send-email-thomas@wytron.com.tw> In-Reply-To: <1295247869-4968-1-git-send-email-thomas@wytron.com.tw> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-EN-UserInfo: 9579962fb128fd4edc0e15f211ef4629:b3dd9e212e2067e834de66fc17565494 X-EN-AuthUser: remote@bootbits.com X-EN-OrigIP: 174.93.215.254 X-EN-OrigHost: unknown Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thomas Chou wrote: [...] > + > +static int altera_spi_txrx(struct spi_device *spi, struct spi_transfer *t) > +{ > + struct altera_spi *hw = to_hw(spi); > + > + hw->tx = t->tx_buf; > + hw->rx = t->rx_buf; > + hw->count = 0; > + hw->bytes_per_word = (t->bits_per_word ? : spi->bits_per_word) / 8; > + hw->len = t->len / hw->bytes_per_word; > + > + if (hw->irq >= 0) { > + init_completion(&hw->done); I think you init this twice, once in altera_spi_probe below as well. > + /* enable receive interrupt */ > + hw->imr |= ALTERA_SPI_CONTROL_IRRDY_MSK; > + writel(hw->imr, hw->base + ALTERA_SPI_CONTROL); > + > + /* send the first byte */ > + writel(hw_txbyte(hw, 0), hw->base + ALTERA_SPI_TXDATA); > + > + wait_for_completion(&hw->done); > + /* disable receive interrupt */ > + hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK; > + writel(hw->imr, hw->base + ALTERA_SPI_CONTROL); > + } else { > + /* send the first byte */ > + writel(hw_txbyte(hw, 0), hw->base + ALTERA_SPI_TXDATA); > + > + while (1) { > + unsigned int rxd; > + > + while (!(readl(hw->base + ALTERA_SPI_STATUS) & > + ALTERA_SPI_STATUS_RRDY_MSK)) > + cpu_relax(); > + > + rxd = readl(hw->base + ALTERA_SPI_RXDATA); > + if (hw->rx) { > + switch (hw->bytes_per_word) { > + case 1: > + hw->rx[hw->count] = rxd; > + break; > + case 2: > + hw->rx[hw->count * 2] = rxd; > + hw->rx[hw->count * 2 + 1] = rxd >> 8; > + break; > + } > + } > + > + hw->count++; > + > + if (hw->count < hw->len) > + writel(hw_txbyte(hw, hw->count), > + hw->base + ALTERA_SPI_TXDATA); > + else > + break; > + } > + > + } > + > + return hw->count * hw->bytes_per_word; > +} > + > +static irqreturn_t altera_spi_irq(int irq, void *dev) > +{ > + struct altera_spi *hw = dev; > + unsigned int rxd; > + > + rxd = readl(hw->base + ALTERA_SPI_RXDATA); > + if (hw->rx) { > + switch (hw->bytes_per_word) { > + case 1: > + hw->rx[hw->count] = rxd; > + break; > + case 2: > + hw->rx[hw->count * 2] = rxd; > + hw->rx[hw->count * 2 + 1] = rxd >> 8; > + break; > + } > + } > + > + hw->count++; > + > + if (hw->count < hw->len) > + writel(hw_txbyte(hw, hw->count), hw->base + ALTERA_SPI_TXDATA); > + else > + complete(&hw->done); > + > + return IRQ_HANDLED; > +} > + > +#ifdef CONFIG_OF > +static int __devinit altera_spi_of_probe(struct platform_device *pdev, > + struct altera_spi *hw) > +{ > + const __be32 *val; > + > + hw->bitbang.master->dev.of_node = pdev->dev.of_node; > + return 0; > +} > +#else > +static int __devinit altera_spi_of_probe(struct platform_device *pdev, > + struct altera_spi *hw) > +{ > + return 0; > +} > +#endif > + > +static int __devinit altera_spi_probe(struct platform_device *pdev) > +{ > + struct altera_spi_platform_data *platp = pdev->dev.platform_data; > + struct altera_spi *hw; > + struct spi_master *master; > + struct resource *res; > + int err = 0; > + > + master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi)); > + if (master == NULL) { > + dev_err(&pdev->dev, "No memory for spi_master\n"); > + err = -ENOMEM; > + goto err_no_mem; > + } > + > + /* setup the master state. */ > + master->bus_num = pdev->id; > + master->num_chipselect = 16; > + master->mode_bits = SPI_CS_HIGH; > + master->setup = altera_spi_setup; > + > + hw = spi_master_get_devdata(master); > + platform_set_drvdata(pdev, hw); > + > + /* setup the state for the bitbang driver */ > + hw->bitbang.master = spi_master_get(master); > + if (hw->bitbang.master == NULL) { > + dev_err(&pdev->dev, "Cannot get device\n"); > + err = -ENODEV; > + goto err_no_dev; > + } > + hw->bitbang.setup_transfer = altera_spi_setupxfer; > + hw->bitbang.chipselect = altera_spi_chipsel; > + hw->bitbang.txrx_bufs = altera_spi_txrx; > + > + /* find and map our resources */ > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + if (res == NULL) { > + dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n"); > + err = -ENOENT; > + goto err_no_iores; > + } > + hw->base = ioremap(res->start, (res->end - res->start) + 1); > + if (hw->base == 0) { > + dev_err(&pdev->dev, "Cannot map IO\n"); > + err = -ENXIO; > + goto err_no_iomap; > + } > + /* program defaults into the registers */ > + hw->imr = 0; /* disable spi interrupts */ > + writel(hw->imr, hw->base + ALTERA_SPI_CONTROL); > + writel(0, hw->base + ALTERA_SPI_STATUS); /* clear status reg */ > + if (readl(hw->base + ALTERA_SPI_STATUS) & ALTERA_SPI_STATUS_RRDY_MSK) > + readl(hw->base + ALTERA_SPI_RXDATA); /* flush rxdata */ > + /* irq is optional */ > + hw->irq = platform_get_irq(pdev, 0); > + if (hw->irq >= 0) { > + init_completion(&hw->done); > + err = request_irq(hw->irq, altera_spi_irq, 0, pdev->name, hw); > + if (err) { > + dev_err(&pdev->dev, "Cannot claim IRQ\n"); > + goto err_no_irq; > + } > + } > + /* find platform data */ > + if (!platp) { > + err = altera_spi_of_probe(pdev, hw); > + if (err) > + goto err_no_of; > + } > + > + /* register our spi controller */ > + err = spi_bitbang_start(&hw->bitbang); > + if (err) { > + dev_err(&pdev->dev, "Failed to register SPI master\n"); > + goto err_register; > + } > + dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq); > + > + return 0; > + > +err_register: > +err_no_of: > + if (hw->irq >= 0) > + free_irq(hw->irq, hw); > +err_no_irq: > + iounmap((void *)hw->base); > +err_no_iomap: > +err_no_iores: > + spi_master_put(master);; > +err_no_mem: > +err_no_dev: > + return err; > +} > + > +static int __devexit altera_spi_remove(struct platform_device *dev) > +{ > + struct altera_spi *hw = platform_get_drvdata(dev); > + struct spi_master *master = hw->bitbang.master; > + > + spi_bitbang_stop(&hw->bitbang); > + > + if (hw->irq >= 0) > + free_irq(hw->irq, hw); > + iounmap((void *)hw->base); > + > + platform_set_drvdata(dev, NULL); > + spi_master_put(master); > + return 0; > +} > + > +#ifdef CONFIG_OF > +static struct of_device_id altera_spi_match[] = { > + { > + .compatible = "altera,spi_altera", > + }, > + {}, > +} > +MODULE_DEVICE_TABLE(of, altera_spi_match); > +#endif > + > +static struct platform_driver altera_spidrv = { > + .remove = __devexit_p(altera_spi_remove), > + .driver = { > + .name = DRV_NAME, > + .owner = THIS_MODULE, > + .pm = NULL, > +#ifdef CONFIG_OF > + .of_match_table = altera_spi_match, > +#endif > + }, > +}; > + > +static int __init altera_spi_init(void) > +{ > + return platform_driver_probe(&altera_spidrv, altera_spi_probe); > +} > + > +static void __exit altera_spi_exit(void) > +{ > + platform_driver_unregister(&altera_spidrv); > +} > + > +module_init(altera_spi_init); > +module_exit(altera_spi_exit); > + > +MODULE_DESCRIPTION("Altera SPI driver"); > +MODULE_AUTHOR("Thomas Chou "); > +MODULE_LICENSE("GPL"); > +MODULE_ALIAS("platform:" DRV_NAME);