text: // SPDX-License-Identifier: GPL-2.0-only
  /* OMAP SSI driver.
   *
   * Copyright (C) 2010 Nokia Corporation. All rights reserved.
   * Copyright (C) 2014 Sebastian Reichel <sre@kernel.org>
   *
   * Contact: Carlos Chinea <carlos.chinea@nokia.com>
   */
  
  #include <linux/compiler.h>
  #include <linux/err.h>
  #include <linux/ioport.h>
  #include <linux/io.h>
  #include <linux/clk.h>
  #include <linux/device.h>
  #include <linux/platform_device.h>
  #include <linux/dma-mapping.h>
  #include <linux/dmaengine.h>
  #include <linux/delay.h>
  #include <linux/seq_file.h>
  #include <linux/scatterlist.h>
  #include <linux/interrupt.h>
  #include <linux/spinlock.h>
  #include <linux/debugfs.h>
  #include <linux/pinctrl/consumer.h>
  #include <linux/pm_runtime.h>
  #include <linux/of_platform.h>
  #include <linux/hsi/hsi.h>
  #include <linux/idr.h>
  
  #include "omap_ssi_regs.h"
  #include "omap_ssi.h"
  
  /* For automatically allocated device IDs */
  static DEFINE_IDA(platform_omap_ssi_ida);
  
  #ifdef CONFIG_DEBUG_FS
  static int ssi_regs_show(struct seq_file *m, void *p __maybe_unused)
  {
  	struct hsi_controller *ssi = m->private;
  	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
  	void __iomem *sys = omap_ssi->sys;
  
  	pm_runtime_get_sync(ssi->device.parent);
  	seq_printf(m, "REVISION\t: 0x%08x\n",  readl(sys + SSI_REVISION_REG));
  	seq_printf(m, "SYSCONFIG\t: 0x%08x\n", readl(sys + SSI_SYSCONFIG_REG));
  	seq_printf(m, "SYSSTATUS\t: 0x%08x\n", readl(sys + SSI_SYSSTATUS_REG));
  	pm_runtime_put(ssi->device.parent);
  
  	return 0;
  }
  
  static int ssi_gdd_regs_show(struct seq_file *m, void *p __maybe_unused)
  {
  	struct hsi_controller *ssi = m->private;
  	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
  	void __iomem *gdd = omap_ssi->gdd;
  	void __iomem *sys = omap_ssi->sys;
  	int lch;
  
  	pm_runtime_get_sync(ssi->device.parent);
  
  	seq_printf(m, "GDD_MPU_STATUS\t: 0x%08x\n",
  		readl(sys + SSI_GDD_MPU_IRQ_STATUS_REG));
  	seq_printf(m, "GDD_MPU_ENABLE\t: 0x%08x\n\n",
  		readl(sys + SSI_GDD_MPU_IRQ_ENABLE_REG));
  	seq_printf(m, "HW_ID\t\t: 0x%08x\n",
  				readl(gdd + SSI_GDD_HW_ID_REG));
  	seq_printf(m, "PPORT_ID\t: 0x%08x\n",
  				readl(gdd + SSI_GDD_PPORT_ID_REG));
  	seq_printf(m, "MPORT_ID\t: 0x%08x\n",
  				readl(gdd + SSI_GDD_MPORT_ID_REG));
  	seq_printf(m, "TEST\t\t: 0x%08x\n",
  				readl(gdd + SSI_GDD_TEST_REG));
  	seq_printf(m, "GCR\t\t: 0x%08x\n",
  				readl(gdd + SSI_GDD_GCR_REG));
  
  	for (lch = 0; lch < SSI_MAX_GDD_LCH; lch++) {
  		seq_printf(m, "\nGDD LCH %d\n=========\n", lch);
  		seq_printf(m, "CSDP\t\t: 0x%04x\n",
  				readw(gdd + SSI_GDD_CSDP_REG(lch)));
  		seq_printf(m, "CCR\t\t: 0x%04x\n",
  				readw(gdd + SSI_GDD_CCR_REG(lch)));
  		seq_printf(m, "CICR\t\t: 0x%04x\n",
  				readw(gdd + SSI_GDD_CICR_REG(lch)));
  		seq_printf(m, "CSR\t\t: 0x%04x\n",
  				readw(gdd + SSI_GDD_CSR_REG(lch)));
  		seq_printf(m, "CSSA\t\t: 0x%08x\n",
  				readl(gdd + SSI_GDD_CSSA_REG(lch)));
  		seq_printf(m, "CDSA\t\t: 0x%08x\n",
  				readl(gdd + SSI_GDD_CDSA_REG(lch)));
  		seq_printf(m, "CEN\t\t: 0x%04x\n",
  				readw(gdd + SSI_GDD_CEN_REG(lch)));
  		seq_printf(m, "CSAC\t\t: 0x%04x\n",
  				readw(gdd + SSI_GDD_CSAC_REG(lch)));
  		seq_printf(m, "CDAC\t\t: 0x%04x\n",
  				readw(gdd + SSI_GDD_CDAC_REG(lch)));
  		seq_printf(m, "CLNK_CTRL\t: 0x%04x\n",
  				readw(gdd + SSI_GDD_CLNK_CTRL_REG(lch)));
  	}
  
  	pm_runtime_put(ssi->device.parent);
  
  	return 0;
  }
  
  DEFINE_SHOW_ATTRIBUTE(ssi_regs);
  DEFINE_SHOW_ATTRIBUTE(ssi_gdd_regs);
  
  static int ssi_debug_add_ctrl(struct hsi_controller *ssi)
  {
  	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
  	struct dentry *dir;
  
  	/* SSI controller */
  	omap_ssi->dir = debugfs_create_dir(dev_name(&ssi->device), NULL);
  	if (!omap_ssi->dir)
  		return -ENOMEM;
  
  	debugfs_create_file("regs", S_IRUGO, omap_ssi->dir, ssi,
  								&ssi_regs_fops);
  	/* SSI GDD (DMA) */
  	dir = debugfs_create_dir("gdd", omap_ssi->dir);
  	if (!dir)
  		goto rback;
  	debugfs_create_file("regs", S_IRUGO, dir, ssi, &ssi_gdd_regs_fops);
  
  	return 0;
  rback:
  	debugfs_remove_recursive(omap_ssi->dir);
  
  	return -ENOMEM;
  }
  
  static void ssi_debug_remove_ctrl(struct hsi_controller *ssi)
  {
  	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
  
  	debugfs_remove_recursive(omap_ssi->dir);
  }
  #endif /* CONFIG_DEBUG_FS */
  
  /*
   * FIXME: Horrible HACK needed until we remove the useless wakeline test
   * in the CMT. To be removed !!!!
   */
  void ssi_waketest(struct hsi_client *cl, unsigned int enable)
  {
  	struct hsi_port *port = hsi_get_port(cl);
  	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
  	struct hsi_controller *ssi = to_hsi_controller(port->device.parent);
  	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
  
  	omap_port->wktest = !!enable;
  	if (omap_port->wktest) {
  		pm_runtime_get_sync(ssi->device.parent);
  		writel_relaxed(SSI_WAKE(0),
  				omap_ssi->sys + SSI_SET_WAKE_REG(port->num));
  	} else {
  		writel_relaxed(SSI_WAKE(0),
  				omap_ssi->sys +	SSI_CLEAR_WAKE_REG(port->num));
  		pm_runtime_put(ssi->device.parent);
  	}
  }
  EXPORT_SYMBOL_GPL(ssi_waketest);
  
  static void ssi_gdd_complete(struct hsi_controller *ssi, unsigned int lch)
  {
  	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
  	struct hsi_msg *msg = omap_ssi->gdd_trn[lch].msg;
  	struct hsi_port *port = to_hsi_port(msg->cl->device.parent);
  	struct omap_ssi_port *omap_port = hsi_port_drvdata(port);
  	unsigned int dir;
  	u32 csr;
  	u32 val;
  
  	spin_lock(&omap_ssi->lock);
  
  	val = readl(omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
  	val &= ~SSI_GDD_LCH(lch);
  	writel_relaxed(val, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG);
  
  	if (msg->ttype == HSI_MSG_READ) {
  		dir = DMA_FROM_DEVICE;
  		val = SSI_DATAAVAILABLE(msg->channel);
  		pm_runtime_put(omap_port->pdev);
  	} else {
  		dir = DMA_TO_DEVICE;
  		val = SSI_DATAACCEPT(msg->channel);
  		/* Keep clocks reference for write pio event */
  	}
  	dma_unmap_sg(&ssi->device, msg->sgt.sgl, msg->sgt.nents, dir);
  	csr = readw(omap_ssi->gdd + SSI_GDD_CSR_REG(lch));
  	omap_ssi->gdd_trn[lch].msg = NULL; /* release GDD lch */
  	dev_dbg(&port->device, "DMA completed ch %d ttype %d\n",
  				msg->channel, msg->ttype);
  	spin_unlock(&omap_ssi->lock);
  	if (csr & SSI_CSR_TOUR) { /* Timeout error */
  		msg->status = HSI_STATUS_ERROR;
  		msg->actual_len = 0;
  		spin_lock(&omap_port->lock);
  		list_del(&msg->link); /* Dequeue msg */
  		spin_unlock(&omap_port->lock);
  
  		list_add_tail(&msg->link, &omap_port->errqueue);
  		schedule_delayed_work(&omap_port->errqueue_work, 0);
  		return;
  	}
  	spin_lock(&omap_port->lock);
  	val |= readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
  	writel_relaxed(val, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0));
  	spin_unlock(&omap_port->lock);
  
  	msg->status = HSI_STATUS_COMPLETED;
  	msg->actual_len = sg_dma_len(msg->sgt.sgl);
  }
  
  static void ssi_gdd_tasklet(unsigned long dev)
  {
  	struct hsi_controller *ssi = (struct hsi_controller *)dev;
  	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
  	void __iomem *sys = omap_ssi->sys;
  	unsigned int lch;
  	u32 status_reg;
  
  	pm_runtime_get(ssi->device.parent);
  
  	if (!pm_runtime_active(ssi->device.parent)) {
  		dev_warn(ssi->device.parent, "ssi_gdd_tasklet called without runtime PM!\n");
  		pm_runtime_put(ssi->device.parent);
  		return;
  	}
  
  	status_reg = readl(sys + SSI_GDD_MPU_IRQ_STATUS_REG);
  	for (lch = 0; lch < SSI_MAX_GDD_LCH; lch++) {
  		if (status_reg & SSI_GDD_LCH(lch))
  			ssi_gdd_complete(ssi, lch);
  	}
  	writel_relaxed(status_reg, sys + SSI_GDD_MPU_IRQ_STATUS_REG);
  	status_reg = readl(sys + SSI_GDD_MPU_IRQ_STATUS_REG);
  
  	pm_runtime_put(ssi->device.parent);
  
  	if (status_reg)
  		tasklet_hi_schedule(&omap_ssi->gdd_tasklet);
  	else
  		enable_irq(omap_ssi->gdd_irq);
  
  }
  
  static irqreturn_t ssi_gdd_isr(int irq, void *ssi)
  {
  	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
  
  	tasklet_hi_schedule(&omap_ssi->gdd_tasklet);
  	disable_irq_nosync(irq);
  
  	return IRQ_HANDLED;
  }
  
  static unsigned long ssi_get_clk_rate(struct hsi_controller *ssi)
  {
  	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
  	unsigned long rate = clk_get_rate(omap_ssi->fck);
  	return rate;
  }
  
  static int ssi_clk_event(struct notifier_block *nb, unsigned long event,
  								void *data)
  {
  	struct omap_ssi_controller *omap_ssi = container_of(nb,
  					struct omap_ssi_controller, fck_nb);
  	struct hsi_controller *ssi = to_hsi_controller(omap_ssi->dev);
  	struct clk_notifier_data *clk_data = data;
  	struct omap_ssi_port *omap_port;
  	int i;
  
  	switch (event) {
  	case PRE_RATE_CHANGE:
  		dev_dbg(&ssi->device, "pre rate change\n");
  
  		for (i = 0; i < ssi->num_ports; i++) {
  			omap_port = omap_ssi->port[i];
  
  			if (!omap_port)
  				continue;
  
  			/* Workaround for SWBREAK + CAwake down race in CMT */
  			disable_irq(omap_port->wake_irq);
  
  			/* stop all ssi communication */
  			pinctrl_pm_select_idle_state(omap_port->pdev);
  			udelay(1); /* wait for racing frames */
  		}
  
  		break;
  	case ABORT_RATE_CHANGE:
  		dev_dbg(&ssi->device, "abort rate change\n");
  		fallthrough;
  	case POST_RATE_CHANGE:
  		dev_dbg(&ssi->device, "post rate change (%lu -> %lu)\n",
  			clk_data->old_rate, clk_data->new_rate);
  		omap_ssi->fck_rate = DIV_ROUND_CLOSEST(clk_data->new_rate, 1000); /* kHz */
  
  		for (i = 0; i < ssi->num_ports; i++) {
  			omap_port = omap_ssi->port[i];
  
  			if (!omap_port)
  				continue;
  
  			omap_ssi_port_update_fclk(ssi, omap_port);
  
  			/* resume ssi communication */
  			pinctrl_pm_select_default_state(omap_port->pdev);
  			enable_irq(omap_port->wake_irq);
  		}
  
  		break;
  	default:
  		break;
  	}
  
  	return NOTIFY_DONE;
  }
  
  static int ssi_get_iomem(struct platform_device *pd,
  		const char *name, void __iomem **pbase, dma_addr_t *phy)
  {
  	struct resource *mem;
  	void __iomem *base;
  	struct hsi_controller *ssi = platform_get_drvdata(pd);
  
  	mem = platform_get_resource_byname(pd, IORESOURCE_MEM, name);
  	base = devm_ioremap_resource(&ssi->device, mem);
  	if (IS_ERR(base))
  		return PTR_ERR(base);
  
  	*pbase = base;
  
  	if (phy)
  		*phy = mem->start;
  
  	return 0;
  }
  
  static int ssi_add_controller(struct hsi_controller *ssi,
  						struct platform_device *pd)
  {
  	struct omap_ssi_controller *omap_ssi;
  	int err;
  
  	omap_ssi = devm_kzalloc(&ssi->device, sizeof(*omap_ssi), GFP_KERNEL);
  	if (!omap_ssi)
  		return -ENOMEM;
  
  	err = ida_simple_get(&platform_omap_ssi_ida, 0, 0, GFP_KERNEL);
  	if (err < 0)
  		return err;
  	ssi->id = err;
  
  	ssi->owner = THIS_MODULE;
  	ssi->device.parent = &pd->dev;
  	dev_set_name(&ssi->device, "ssi%d", ssi->id);
  	hsi_controller_set_drvdata(ssi, omap_ssi);
  	omap_ssi->dev = &ssi->device;
  	err = ssi_get_iomem(pd, "sys", &omap_ssi->sys, NULL);
  	if (err < 0)
  		goto out_err;
  	err = ssi_get_iomem(pd, "gdd", &omap_ssi->gdd, NULL);
  	if (err < 0)
  		goto out_err;
  	err = platform_get_irq_byname(pd, "gdd_mpu");
  	if (err < 0)
  		goto out_err;
  	omap_ssi->gdd_irq = err;
  	tasklet_init(&omap_ssi->gdd_tasklet, ssi_gdd_tasklet,
  							(unsigned long)ssi);
  	err = devm_request_irq(&ssi->device, omap_ssi->gdd_irq, ssi_gdd_isr,
  						0, "gdd_mpu", ssi);
  	if (err < 0) {
  		dev_err(&ssi->device, "Request GDD IRQ %d failed (%d)",
  							omap_ssi->gdd_irq, err);
  		goto out_err;
  	}
  
  	omap_ssi->port = devm_kcalloc(&ssi->device, ssi->num_ports,
  				      sizeof(*omap_ssi->port), GFP_KERNEL);
  	if (!omap_ssi->port) {
  		err = -ENOMEM;
  		goto out_err;
  	}
  
  	omap_ssi->fck = devm_clk_get(&ssi->device, "ssi_ssr_fck");
  	if (IS_ERR(omap_ssi->fck)) {
  		dev_err(&pd->dev, "Could not acquire clock \"ssi_ssr_fck\": %li\n",
  			PTR_ERR(omap_ssi->fck));
  		err = -ENODEV;
  		goto out_err;
  	}
  
  	omap_ssi->fck_nb.notifier_call = ssi_clk_event;
  	omap_ssi->fck_nb.priority = INT_MAX;
  	clk_notifier_register(omap_ssi->fck, &omap_ssi->fck_nb);
  
  	/* TODO: find register, which can be used to detect context loss */
  	omap_ssi->get_loss = NULL;
  
  	omap_ssi->max_speed = UINT_MAX;
  	spin_lock_init(&omap_ssi->lock);
  	err = hsi_register_controller(ssi);
  
  	if (err < 0)
  		goto out_err;
  
  	return 0;
  
  out_err:
  	ida_simple_remove(&platform_omap_ssi_ida, ssi->id);
  	return err;
  }
  
  static int ssi_hw_init(struct hsi_controller *ssi)
  {
  	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
  	int err;
  
  	err = pm_runtime_resume_and_get(ssi->device.parent);
  	if (err < 0) {
  		dev_err(&ssi->device, "runtime PM failed %d\n", err);
  		return err;
  	}
  	/* Resetting GDD */
  	writel_relaxed(SSI_SWRESET, omap_ssi->gdd + SSI_GDD_GRST_REG);
  	/* Get FCK rate in kHz */
  	omap_ssi->fck_rate = DIV_ROUND_CLOSEST(ssi_get_clk_rate(ssi), 1000);
  	dev_dbg(&ssi->device, "SSI fck rate %lu kHz\n", omap_ssi->fck_rate);
  
  	writel_relaxed(SSI_CLK_AUTOGATING_ON, omap_ssi->sys + SSI_GDD_GCR_REG);
  	omap_ssi->gdd_gcr = SSI_CLK_AUTOGATING_ON;
  	pm_runtime_put_sync(ssi->device.parent);
  
  	return 0;
  }
  
  static void ssi_remove_controller(struct hsi_controller *ssi)
  {
  	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
  	int id = ssi->id;
  	tasklet_kill(&omap_ssi->gdd_tasklet);
  	hsi_unregister_controller(ssi);
  	clk_notifier_unregister(omap_ssi->fck, &omap_ssi->fck_nb);
  	ida_simple_remove(&platform_omap_ssi_ida, id);
  }
  
  static inline int ssi_of_get_available_ports_count(const struct device_node *np)
  {
  	struct device_node *child;
  	int num = 0;
  
  	for_each_available_child_of_node(np, child)
  		if (of_device_is_compatible(child, "ti,omap3-ssi-port"))
  			num++;
  
  	return num;
  }
  
  static int ssi_remove_ports(struct device *dev, void *c)
  {
  	struct platform_device *pdev = to_platform_device(dev);
  
  	if (!dev->of_node)
  		return 0;
  
  	of_node_clear_flag(dev->of_node, OF_POPULATED);
  	of_device_unregister(pdev);
  
  	return 0;
  }
  
  static int ssi_probe(struct platform_device *pd)
  {
  	struct platform_device *childpdev;
  	struct device_node *np = pd->dev.of_node;
  	struct device_node *child;
  	struct hsi_controller *ssi;
  	int err;
  	int num_ports;
  
  	if (!np) {
  		dev_err(&pd->dev, "missing device tree data\n");
  		return -EINVAL;
  	}
  
  	num_ports = ssi_of_get_available_ports_count(np);
  
  	ssi = hsi_alloc_controller(num_ports, GFP_KERNEL);
  	if (!ssi) {
  		dev_err(&pd->dev, "No memory for controller\n");
  		return -ENOMEM;
  	}
  
  	platform_set_drvdata(pd, ssi);
  
  	err = ssi_add_controller(ssi, pd);
  	if (err < 0)
  		goto out1;
  
  	pm_runtime_enable(&pd->dev);
  
  	err = ssi_hw_init(ssi);
  	if (err < 0)
  		goto out2;
  #ifdef CONFIG_DEBUG_FS
  	err = ssi_debug_add_ctrl(ssi);
  	if (err < 0)
  		goto out2;
  #endif
  
  	for_each_available_child_of_node(np, child) {
  		if (!of_device_is_compatible(child, "ti,omap3-ssi-port"))
  			continue;
  
  		childpdev = of_platform_device_create(child, NULL, &pd->dev);
  		if (!childpdev) {
  			err = -ENODEV;
  			dev_err(&pd->dev, "failed to create ssi controller port\n");
  			goto out3;
  		}
  	}
  
  	dev_info(&pd->dev, "ssi controller %d initialized (%d ports)!\n",
  		ssi->id, num_ports);
  	return err;
  out3:
  	device_for_each_child(&pd->dev, NULL, ssi_remove_ports);
  out2:
  	ssi_remove_controller(ssi);
  out1:
  	platform_set_drvdata(pd, NULL);
  	pm_runtime_disable(&pd->dev);
  
  	return err;
  }
  
  static int ssi_remove(struct platform_device *pd)
  {
  	struct hsi_controller *ssi = platform_get_drvdata(pd);
  
  	/* cleanup of of_platform_populate() call */
  	device_for_each_child(&pd->dev, NULL, ssi_remove_ports);
  
  #ifdef CONFIG_DEBUG_FS
  	ssi_debug_remove_ctrl(ssi);
  #endif
  	ssi_remove_controller(ssi);
  	platform_set_drvdata(pd, NULL);
  
  	pm_runtime_disable(&pd->dev);
  
  	return 0;
  }
  
  #ifdef CONFIG_PM
  static int omap_ssi_runtime_suspend(struct device *dev)
  {
  	struct hsi_controller *ssi = dev_get_drvdata(dev);
  	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
  
  	dev_dbg(dev, "runtime suspend!\n");
  
  	if (omap_ssi->get_loss)
  		omap_ssi->loss_count =
  				omap_ssi->get_loss(ssi->device.parent);
  
  	return 0;
  }
  
  static int omap_ssi_runtime_resume(struct device *dev)
  {
  	struct hsi_controller *ssi = dev_get_drvdata(dev);
  	struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi);
  
  	dev_dbg(dev, "runtime resume!\n");
  
  	if ((omap_ssi->get_loss) && (omap_ssi->loss_count ==
  				omap_ssi->get_loss(ssi->device.parent)))
  		return 0;
  
  	writel_relaxed(omap_ssi->gdd_gcr, omap_ssi->gdd + SSI_GDD_GCR_REG);
  
  	return 0;
  }
  
  static const struct dev_pm_ops omap_ssi_pm_ops = {
  	SET_RUNTIME_PM_OPS(omap_ssi_runtime_suspend, omap_ssi_runtime_resume,
  		NULL)
  };
  
  #define DEV_PM_OPS     (&omap_ssi_pm_ops)
  #else
  #define DEV_PM_OPS     NULL
  #endif
  
  #ifdef CONFIG_OF
  static const struct of_device_id omap_ssi_of_match[] = {
  	{ .compatible = "ti,omap3-ssi", },
  	{},
  };
  MODULE_DEVICE_TABLE(of, omap_ssi_of_match);
  #else
  #define omap_ssi_of_match NULL
  #endif
  
  static struct platform_driver ssi_pdriver = {
  	.probe = ssi_probe,
  	.remove	= ssi_remove,
  	.driver	= {
  		.name	= "omap_ssi",
  		.pm     = DEV_PM_OPS,
  		.of_match_table = omap_ssi_of_match,
  	},
  };
  
  static int __init ssi_init(void) {
  	int ret;
  
  	ret = platform_driver_register(&ssi_pdriver);
  	if (ret)
  		return ret;
  
  	return platform_driver_register(&ssi_port_pdriver);
  }
  module_init(ssi_init);
  
  static void __exit ssi_exit(void) {
  	platform_driver_unregister(&ssi_port_pdriver);
  	platform_driver_unregister(&ssi_pdriver);
  }
  module_exit(ssi_exit);
  
  MODULE_ALIAS("platform:omap_ssi");
  MODULE_AUTHOR("Carlos Chinea <carlos.chinea@nokia.com>");
  MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
  MODULE_DESCRIPTION("Synchronous Serial Interface Driver");
  MODULE_LICENSE("GPL v2");
  