// SPDX-License-Identifier: GPL-2.0-only
/* OMAP SSI driver.
*
* Copyright (C) 2010 Nokia Corporation. All rights reserved.
* Copyright (C) 2014 Sebastian Reichel <[email protected]>
*
* Contact: Carlos Chinea <[email protected]>
*/
#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/hsi/ssi_protocol.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.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);
debugfs_create_file("regs", S_IRUGO, omap_ssi->dir, ssi, &ssi_regs_fops);
/* SSI GDD (DMA) */
dir = debugfs_create_dir("gdd", omap_ssi->dir);
debugfs_create_file("regs", S_IRUGO, dir, ssi, &ssi_gdd_regs_fops);
return 0;
}
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_alloc(&platform_omap_ssi_ida, 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_free(&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_free(&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) {
hsi_put_controller(ssi);
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");
of_node_put(child);
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);
pm_runtime_disable(&pd->dev);
out1:
platform_set_drvdata(pd, NULL);
return err;
}
static void 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);
}
#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_new = 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;
ret = platform_driver_register(&ssi_port_pdriver);
if (ret) {
platform_driver_unregister(&ssi_pdriver);
return ret;
}
return 0;
}
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 <[email protected]>");
MODULE_AUTHOR("Sebastian Reichel <[email protected]>");
MODULE_DESCRIPTION("Synchronous Serial Interface Driver");
MODULE_LICENSE("GPL v2");
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