Patchwork [1/1] ata: Add iMX pata support

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Submitter Arnaud Patard (Rtp)
Date July 26, 2011, 2:58 p.m.
Message ID <20110726145835.654310365@rtp-net.org>
Download mbox | patch
Permalink /patch/106878/
State Not Applicable
Delegated to: David Miller
Headers show

Comments

Arnaud Patard (Rtp) - July 26, 2011, 2:58 p.m.
Add basic support for pata on iMX. It has been tested only on imx51.
SDMA support will probably be added later so this version supports only
PIO.

v2:
  - enable only when needed IORDY
  - use dev_get_drvdata
v3:
  - add missing clk_put() calls
  - use platform_get_irq()
  - fix resume code to avoid disabling IORDY on resume
v4:
  - Remove EXPERIMENTAL and switch to depends on ARCH_MXC
  - Use devm_kzalloc()
  - make clock a must-have
  - Use only 1 ioremap

Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>


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Patch

Index: linux-2.6-submit/drivers/ata/Kconfig
===================================================================
--- linux-2.6-submit.orig/drivers/ata/Kconfig	2011-07-26 12:07:59.000000000 +0200
+++ linux-2.6-submit/drivers/ata/Kconfig	2011-07-26 12:08:10.000000000 +0200
@@ -467,6 +467,15 @@  config PATA_ICSIDE
 	  interface card.  This is not required for ICS partition support.
 	  If you are unsure, say N to this.
 
+config PATA_IMX
+	tristate "PATA support for Freescale iMX"
+	depends on ARCH_MXC
+	help
+	  This option enables support for the PATA host available on Freescale
+          iMX SoCs.
+
+	  If unsure, say N.
+
 config PATA_IT8213
 	tristate "IT8213 PATA support (Experimental)"
 	depends on PCI && EXPERIMENTAL
Index: linux-2.6-submit/drivers/ata/Makefile
===================================================================
--- linux-2.6-submit.orig/drivers/ata/Makefile	2011-07-26 12:07:59.000000000 +0200
+++ linux-2.6-submit/drivers/ata/Makefile	2011-07-26 12:08:10.000000000 +0200
@@ -48,6 +48,7 @@  obj-$(CONFIG_PATA_HPT37X)	+= pata_hpt37x
 obj-$(CONFIG_PATA_HPT3X2N)	+= pata_hpt3x2n.o
 obj-$(CONFIG_PATA_HPT3X3)	+= pata_hpt3x3.o
 obj-$(CONFIG_PATA_ICSIDE)	+= pata_icside.o
+obj-$(CONFIG_PATA_IMX)		+= pata_imx.o
 obj-$(CONFIG_PATA_IT8213)	+= pata_it8213.o
 obj-$(CONFIG_PATA_IT821X)	+= pata_it821x.o
 obj-$(CONFIG_PATA_JMICRON)	+= pata_jmicron.o
Index: linux-2.6-submit/drivers/ata/pata_imx.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6-submit/drivers/ata/pata_imx.c	2011-07-26 14:45:43.000000000 +0200
@@ -0,0 +1,253 @@ 
+/*
+ * Freescale iMX PATA driver
+ *
+ * Copyright (C) 2011 Arnaud Patard <arnaud.patard@rtp-net.org>
+ *
+ * Based on pata_platform - Copyright (C) 2006 - 2007  Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * TODO:
+ * - dmaengine support
+ * - check if timing stuff needed
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <scsi/scsi_host.h>
+#include <linux/ata.h>
+#include <linux/libata.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+
+#define DRV_NAME "pata_imx"
+
+#define PATA_IMX_ATA_CONTROL		0x24
+#define PATA_IMX_ATA_CTRL_FIFO_RST_B	(1<<7)
+#define PATA_IMX_ATA_CTRL_ATA_RST_B	(1<<6)
+#define PATA_IMX_ATA_CTRL_IORDY_EN	(1<<0)
+#define PATA_IMX_ATA_INT_EN		0x2C
+#define PATA_IMX_ATA_INTR_ATA_INTRQ2	(1<<3)
+#define PATA_IMX_DRIVE_DATA		0xA0
+#define PATA_IMX_DRIVE_CONTROL		0xD8
+
+struct pata_imx_priv {
+	struct clk *clk;
+	/* timings/interrupt/control regs */
+	u8 *host_regs;
+	u32 ata_ctl;
+};
+
+static int pata_imx_set_mode(struct ata_link *link, struct ata_device **unused)
+{
+	struct ata_device *dev;
+	struct ata_port *ap = link->ap;
+	struct pata_imx_priv *priv = ap->host->private_data;
+	u32 val;
+
+	ata_for_each_dev(dev, link, ENABLED) {
+		dev->pio_mode = dev->xfer_mode = XFER_PIO_0;
+		dev->xfer_shift = ATA_SHIFT_PIO;
+		dev->flags |= ATA_DFLAG_PIO;
+
+		val = __raw_readl(priv->host_regs + PATA_IMX_ATA_CONTROL);
+		if (ata_pio_need_iordy(dev))
+			val |= PATA_IMX_ATA_CTRL_IORDY_EN;
+		else
+			val &= ~PATA_IMX_ATA_CTRL_IORDY_EN;
+		__raw_writel(val, priv->host_regs + PATA_IMX_ATA_CONTROL);
+
+		ata_dev_printk(dev, KERN_INFO, "configured for PIO\n");
+	}
+	return 0;
+}
+
+static struct scsi_host_template pata_imx_sht = {
+	ATA_PIO_SHT(DRV_NAME),
+};
+
+static struct ata_port_operations pata_imx_port_ops = {
+	.inherits		= &ata_sff_port_ops,
+	.sff_data_xfer		= ata_sff_data_xfer_noirq,
+	.cable_detect		= ata_cable_unknown,
+	.set_mode		= pata_imx_set_mode,
+};
+
+static void pata_imx_setup_port(struct ata_ioports *ioaddr)
+{
+	/* Fixup the port shift for platforms that need it */
+	ioaddr->data_addr	= ioaddr->cmd_addr + (ATA_REG_DATA    << 2);
+	ioaddr->error_addr	= ioaddr->cmd_addr + (ATA_REG_ERR     << 2);
+	ioaddr->feature_addr	= ioaddr->cmd_addr + (ATA_REG_FEATURE << 2);
+	ioaddr->nsect_addr	= ioaddr->cmd_addr + (ATA_REG_NSECT   << 2);
+	ioaddr->lbal_addr	= ioaddr->cmd_addr + (ATA_REG_LBAL    << 2);
+	ioaddr->lbam_addr	= ioaddr->cmd_addr + (ATA_REG_LBAM    << 2);
+	ioaddr->lbah_addr	= ioaddr->cmd_addr + (ATA_REG_LBAH    << 2);
+	ioaddr->device_addr	= ioaddr->cmd_addr + (ATA_REG_DEVICE  << 2);
+	ioaddr->status_addr	= ioaddr->cmd_addr + (ATA_REG_STATUS  << 2);
+	ioaddr->command_addr	= ioaddr->cmd_addr + (ATA_REG_CMD     << 2);
+}
+
+static int __devinit pata_imx_probe(struct platform_device *pdev)
+{
+	struct ata_host *host;
+	struct ata_port *ap;
+	struct pata_imx_priv *priv;
+	int irq = 0;
+	struct resource *io_res;
+
+	io_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (io_res == NULL)
+		return -EINVAL;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq <= 0)
+		return -EINVAL;
+
+	priv = devm_kzalloc(&pdev->dev,
+				sizeof(struct pata_imx_priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(priv->clk)) {
+		dev_err(&pdev->dev, "Failed to get clock\n");
+		return PTR_ERR(priv->clk);
+	}
+
+	clk_enable(priv->clk);
+
+	host = ata_host_alloc(&pdev->dev, 1);
+	if (!host)
+		goto free_priv;
+
+	host->private_data = priv;
+	ap = host->ports[0];
+
+	ap->ops = &pata_imx_port_ops;
+	ap->pio_mask = ATA_PIO0;
+	ap->flags |= ATA_FLAG_SLAVE_POSS;
+
+	priv->host_regs = devm_ioremap(&pdev->dev, io_res->start,
+		resource_size(io_res));
+	if (!priv->host_regs) {
+		dev_err(&pdev->dev, "failed to map IO/CTL base\n");
+		goto free_priv;
+	}
+
+	ap->ioaddr.cmd_addr = priv->host_regs + PATA_IMX_DRIVE_DATA;
+	ap->ioaddr.ctl_addr = priv->host_regs + PATA_IMX_DRIVE_CONTROL;
+
+	ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;
+
+	pata_imx_setup_port(&ap->ioaddr);
+
+	ata_port_desc(ap, "cmd 0x%llx ctl 0x%llx",
+		(unsigned long long)io_res->start + PATA_IMX_DRIVE_DATA,
+		(unsigned long long)io_res->start + PATA_IMX_DRIVE_CONTROL);
+
+	/* deassert resets */
+	__raw_writel(PATA_IMX_ATA_CTRL_FIFO_RST_B |
+			PATA_IMX_ATA_CTRL_ATA_RST_B,
+			priv->host_regs + PATA_IMX_ATA_CONTROL);
+	/* enable interrupts */
+	__raw_writel(PATA_IMX_ATA_INTR_ATA_INTRQ2,
+			priv->host_regs + PATA_IMX_ATA_INT_EN);
+
+	/* activate */
+	return ata_host_activate(host, irq, ata_sff_interrupt, 0,
+				&pata_imx_sht);
+
+free_priv:
+	clk_disable(priv->clk);
+	clk_put(priv->clk);
+	return -ENOMEM;
+}
+
+static int __devexit pata_imx_remove(struct platform_device *pdev)
+{
+	struct ata_host *host = dev_get_drvdata(&pdev->dev);
+	struct pata_imx_priv *priv = host->private_data;
+
+	ata_host_detach(host);
+
+	__raw_writel(0, priv->host_regs + PATA_IMX_ATA_INT_EN);
+
+	clk_disable(priv->clk);
+	clk_put(priv->clk);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int pata_imx_suspend(struct device *dev)
+{
+	struct ata_host *host = dev_get_drvdata(dev);
+	struct pata_imx_priv *priv = host->private_data;
+	int ret;
+
+	ret = ata_host_suspend(host, PMSG_SUSPEND);
+	if (!ret) {
+		__raw_writel(0, priv->host_regs + PATA_IMX_ATA_INT_EN);
+		priv->ata_ctl =
+			__raw_readl(priv->host_regs + PATA_IMX_ATA_CONTROL);
+		clk_disable(priv->clk);
+	}
+
+	return ret;
+}
+
+static int pata_imx_resume(struct device *dev)
+{
+	struct ata_host *host = dev_get_drvdata(dev);
+	struct pata_imx_priv *priv = host->private_data;
+
+	clk_enable(priv->clk);
+
+	__raw_writel(priv->ata_ctl, priv->host_regs + PATA_IMX_ATA_CONTROL);
+
+	__raw_writel(PATA_IMX_ATA_INTR_ATA_INTRQ2,
+			priv->host_regs + PATA_IMX_ATA_INT_EN);
+
+	ata_host_resume(host);
+
+	return 0;
+}
+
+static const struct dev_pm_ops pata_imx_pm_ops = {
+	.suspend	= pata_imx_suspend,
+	.resume		= pata_imx_resume,
+};
+#endif
+
+static struct platform_driver pata_imx_driver = {
+	.probe		= pata_imx_probe,
+	.remove		= __devexit_p(pata_imx_remove),
+	.driver = {
+		.name		= DRV_NAME,
+		.owner		= THIS_MODULE,
+#ifdef CONFIG_PM
+		.pm		= &pata_imx_pm_ops,
+#endif
+	},
+};
+
+static int __init pata_imx_init(void)
+{
+	return platform_driver_register(&pata_imx_driver);
+}
+
+static void __exit pata_imx_exit(void)
+{
+	platform_driver_unregister(&pata_imx_driver);
+}
+module_init(pata_imx_init);
+module_exit(pata_imx_exit);
+
+MODULE_AUTHOR("Arnaud Patard <arnaud.patard@rtp-net.org>");
+MODULE_DESCRIPTION("low-level driver for iMX PATA");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);