#include <linux/acpi.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/property.h>
#include <linux/reset.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <asm/byteorder.h>
#include <linux/serial_8250.h>
#include <linux/serial_reg.h>
#include "8250_dwlib.h"
#define DW_UART_USR 0x1f /* UART Status Register */
#define DW_UART_DMASA 0xa8 /* DMA Software Ack */
#define OCTEON_UART_USR 0x27 /* UART Status Register */
#define RZN1_UART_TDMACR 0x10c /* DMA Control Register Transmit Mode */
#define RZN1_UART_RDMACR 0x110 /* DMA Control Register Receive Mode */
#define DW_UART_MCR_SIRE BIT(6)
#define RZN1_UART_xDMACR_DMA_EN BIT(0)
#define RZN1_UART_xDMACR_1_WORD_BURST (0 << 1)
#define RZN1_UART_xDMACR_4_WORD_BURST (1 << 1)
#define RZN1_UART_xDMACR_8_WORD_BURST (2 << 1)
#define RZN1_UART_xDMACR_BLK_SZ(x) ((x) << 3)
#define DW_UART_QUIRK_OCTEON BIT(0)
#define DW_UART_QUIRK_ARMADA_38X BIT(1)
#define DW_UART_QUIRK_SKIP_SET_RATE BIT(2)
#define DW_UART_QUIRK_IS_DMA_FC BIT(3)
static inline struct dw8250_data *clk_to_dw8250_data(struct notifier_block *nb)
{
return container_of(nb, struct dw8250_data, clk_notifier);
}
static inline struct dw8250_data *work_to_dw8250_data(struct work_struct *work)
{
return container_of(work, struct dw8250_data, clk_work);
}
static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value)
{
struct dw8250_data *d = to_dw8250_data(p->private_data);
if (offset == UART_MSR) {
value |= d->msr_mask_on;
value &= ~d->msr_mask_off;
}
return value;
}
static void dw8250_force_idle(struct uart_port *p)
{
struct uart_8250_port *up = up_to_u8250p(p);
unsigned int lsr;
serial8250_clear_and_reinit_fifos(up);
if (up->fcr & UART_FCR_ENABLE_FIFO) {
lsr = p->serial_in(p, UART_LSR);
if (!(lsr & UART_LSR_DR))
return;
}
(void)p->serial_in(p, UART_RX);
}
static void dw8250_check_lcr(struct uart_port *p, int value)
{
void __iomem *offset = p->membase + (UART_LCR << p->regshift);
int tries = 1000;
while (tries--) {
unsigned int lcr = p->serial_in(p, UART_LCR);
if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
return;
dw8250_force_idle(p);
#ifdef CONFIG_64BIT
if (p->type == PORT_OCTEON)
__raw_writeq(value & 0xff, offset);
else
#endif
if (p->iotype == UPIO_MEM32)
writel(value, offset);
else if (p->iotype == UPIO_MEM32BE)
iowrite32be(value, offset);
else
writeb(value, offset);
}
}
static void dw8250_tx_wait_empty(struct uart_port *p)
{
struct uart_8250_port *up = up_to_u8250p(p);
unsigned int tries = 20000;
unsigned int delay_threshold = tries - 1000;
unsigned int lsr;
while (tries--) {
lsr = readb (p->membase + (UART_LSR << p->regshift));
up->lsr_saved_flags |= lsr & up->lsr_save_mask;
if (lsr & UART_LSR_TEMT)
break;
if (tries < delay_threshold)
udelay (1);
}
}
static void dw8250_serial_out(struct uart_port *p, int offset, int value)
{
struct dw8250_data *d = to_dw8250_data(p->private_data);
writeb(value, p->membase + (offset << p->regshift));
if (offset == UART_LCR && !d->uart_16550_compatible)
dw8250_check_lcr(p, value);
}
static void dw8250_serial_out38x(struct uart_port *p, int offset, int value)
{
if (offset == UART_LCR)
dw8250_tx_wait_empty(p);
dw8250_serial_out(p, offset, value);
}
static unsigned int dw8250_serial_in(struct uart_port *p, int offset)
{
unsigned int value = readb(p->membase + (offset << p->regshift));
return dw8250_modify_msr(p, offset, value);
}
#ifdef CONFIG_64BIT
static unsigned int dw8250_serial_inq(struct uart_port *p, int offset)
{
unsigned int value;
value = (u8)__raw_readq(p->membase + (offset << p->regshift));
return dw8250_modify_msr(p, offset, value);
}
static void dw8250_serial_outq(struct uart_port *p, int offset, int value)
{
struct dw8250_data *d = to_dw8250_data(p->private_data);
value &= 0xff;
__raw_writeq(value, p->membase + (offset << p->regshift));
__raw_readq(p->membase + (UART_LCR << p->regshift));
if (offset == UART_LCR && !d->uart_16550_compatible)
dw8250_check_lcr(p, value);
}
#endif /* CONFIG_64BIT */
static void dw8250_serial_out32(struct uart_port *p, int offset, int value)
{
struct dw8250_data *d = to_dw8250_data(p->private_data);
writel(value, p->membase + (offset << p->regshift));
if (offset == UART_LCR && !d->uart_16550_compatible)
dw8250_check_lcr(p, value);
}
static unsigned int dw8250_serial_in32(struct uart_port *p, int offset)
{
unsigned int value = readl(p->membase + (offset << p->regshift));
return dw8250_modify_msr(p, offset, value);
}
static void dw8250_serial_out32be(struct uart_port *p, int offset, int value)
{
struct dw8250_data *d = to_dw8250_data(p->private_data);
iowrite32be(value, p->membase + (offset << p->regshift));
if (offset == UART_LCR && !d->uart_16550_compatible)
dw8250_check_lcr(p, value);
}
static unsigned int dw8250_serial_in32be(struct uart_port *p, int offset)
{
unsigned int value = ioread32be(p->membase + (offset << p->regshift));
return dw8250_modify_msr(p, offset, value);
}
static int dw8250_handle_irq(struct uart_port *p)
{
struct uart_8250_port *up = up_to_u8250p(p);
struct dw8250_data *d = to_dw8250_data(p->private_data);
unsigned int iir = p->serial_in(p, UART_IIR);
bool rx_timeout = (iir & 0x3f) == UART_IIR_RX_TIMEOUT;
unsigned int quirks = d->pdata->quirks;
unsigned int status;
unsigned long flags;
if (!up->dma && rx_timeout) {
spin_lock_irqsave(&p->lock, flags);
status = serial_lsr_in(up);
if (!(status & (UART_LSR_DR | UART_LSR_BI)))
(void) p->serial_in(p, UART_RX);
spin_unlock_irqrestore(&p->lock, flags);
}
if (quirks & DW_UART_QUIRK_IS_DMA_FC && up->dma && up->dma->rx_running && rx_timeout) {
spin_lock_irqsave(&p->lock, flags);
status = serial_lsr_in(up);
spin_unlock_irqrestore(&p->lock, flags);
if (status & (UART_LSR_DR | UART_LSR_BI)) {
dw8250_writel_ext(p, RZN1_UART_RDMACR, 0);
dw8250_writel_ext(p, DW_UART_DMASA, 1);
}
}
if (serial8250_handle_irq(p, iir))
return 1;
if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
(void)p->serial_in(p, d->pdata->usr_reg);
return 1;
}
return 0;
}
static void dw8250_clk_work_cb(struct work_struct *work)
{
struct dw8250_data *d = work_to_dw8250_data(work);
struct uart_8250_port *up;
unsigned long rate;
rate = clk_get_rate(d->clk);
if (rate <= 0)
return;
up = serial8250_get_port(d->data.line);
serial8250_update_uartclk(&up->port, rate);
}
static int dw8250_clk_notifier_cb(struct notifier_block *nb,
unsigned long event, void *data)
{
struct dw8250_data *d = clk_to_dw8250_data(nb);
if (event == POST_RATE_CHANGE) {
queue_work(system_unbound_wq, &d->clk_work);
return NOTIFY_OK;
}
return NOTIFY_DONE;
}
static void
dw8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
{
if (!state)
pm_runtime_get_sync(port->dev);
serial8250_do_pm(port, state, old);
if (state)
pm_runtime_put_sync_suspend(port->dev);
}
static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,
const struct ktermios *old)
{
unsigned long newrate = tty_termios_baud_rate(termios) * 16;
struct dw8250_data *d = to_dw8250_data(p->private_data);
long rate;
int ret;
clk_disable_unprepare(d->clk);
rate = clk_round_rate(d->clk, newrate);
if (rate > 0) {
ret = clk_set_rate(d->clk, newrate);
if (!ret)
p->uartclk = rate;
}
clk_prepare_enable(d->clk);
dw8250_do_set_termios(p, termios, old);
}
static void dw8250_set_ldisc(struct uart_port *p, struct ktermios *termios)
{
struct uart_8250_port *up = up_to_u8250p(p);
unsigned int mcr = p->serial_in(p, UART_MCR);
if (up->capabilities & UART_CAP_IRDA) {
if (termios->c_line == N_IRDA)
mcr |= DW_UART_MCR_SIRE;
else
mcr &= ~DW_UART_MCR_SIRE;
p->serial_out(p, UART_MCR, mcr);
}
serial8250_do_set_ldisc(p, termios);
}
static bool dw8250_fallback_dma_filter(struct dma_chan *chan, void *param)
{
return false;
}
static bool dw8250_idma_filter(struct dma_chan *chan, void *param)
{
return param == chan->device->dev;
}
static u32 dw8250_rzn1_get_dmacr_burst(int max_burst)
{
if (max_burst >= 8)
return RZN1_UART_xDMACR_8_WORD_BURST;
else if (max_burst >= 4)
return RZN1_UART_xDMACR_4_WORD_BURST;
else
return RZN1_UART_xDMACR_1_WORD_BURST;
}
static void dw8250_prepare_tx_dma(struct uart_8250_port *p)
{
struct uart_port *up = &p->port;
struct uart_8250_dma *dma = p->dma;
u32 val;
dw8250_writel_ext(up, RZN1_UART_TDMACR, 0);
val = dw8250_rzn1_get_dmacr_burst(dma->txconf.dst_maxburst) |
RZN1_UART_xDMACR_BLK_SZ(dma->tx_size) |
RZN1_UART_xDMACR_DMA_EN;
dw8250_writel_ext(up, RZN1_UART_TDMACR, val);
}
static void dw8250_prepare_rx_dma(struct uart_8250_port *p)
{
struct uart_port *up = &p->port;
struct uart_8250_dma *dma = p->dma;
u32 val;
dw8250_writel_ext(up, RZN1_UART_RDMACR, 0);
val = dw8250_rzn1_get_dmacr_burst(dma->rxconf.src_maxburst) |
RZN1_UART_xDMACR_BLK_SZ(dma->rx_size) |
RZN1_UART_xDMACR_DMA_EN;
dw8250_writel_ext(up, RZN1_UART_RDMACR, val);
}
static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
{
struct device_node *np = p->dev->of_node;
if (np) {
unsigned int quirks = data->pdata->quirks;
int id;
id = of_alias_get_id(np, "serial");
if (id >= 0)
p->line = id;
#ifdef CONFIG_64BIT
if (quirks & DW_UART_QUIRK_OCTEON) {
p->serial_in = dw8250_serial_inq;
p->serial_out = dw8250_serial_outq;
p->flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE;
p->type = PORT_OCTEON;
data->skip_autocfg = true;
}
#endif
if (of_device_is_big_endian(np)) {
p->iotype = UPIO_MEM32BE;
p->serial_in = dw8250_serial_in32be;
p->serial_out = dw8250_serial_out32be;
}
if (quirks & DW_UART_QUIRK_ARMADA_38X)
p->serial_out = dw8250_serial_out38x;
if (quirks & DW_UART_QUIRK_SKIP_SET_RATE)
p->set_termios = dw8250_do_set_termios;
if (quirks & DW_UART_QUIRK_IS_DMA_FC) {
data->data.dma.txconf.device_fc = 1;
data->data.dma.rxconf.device_fc = 1;
data->data.dma.prepare_tx_dma = dw8250_prepare_tx_dma;
data->data.dma.prepare_rx_dma = dw8250_prepare_rx_dma;
}
} else if (acpi_dev_present("APMC0D08", NULL, -1)) {
p->iotype = UPIO_MEM32;
p->regshift = 2;
p->serial_in = dw8250_serial_in32;
data->uart_16550_compatible = true;
}
if (platform_get_resource_byname(to_platform_device(p->dev),
IORESOURCE_MEM, "lpss_priv")) {
data->data.dma.rx_param = p->dev->parent;
data->data.dma.tx_param = p->dev->parent;
data->data.dma.fn = dw8250_idma_filter;
}
}
static void dw8250_clk_disable_unprepare(void *data)
{
clk_disable_unprepare(data);
}
static void dw8250_reset_control_assert(void *data)
{
reset_control_assert(data);
}
static int dw8250_probe(struct platform_device *pdev)
{
struct uart_8250_port uart = {}, *up = &uart;
struct uart_port *p = &up->port;
struct device *dev = &pdev->dev;
struct dw8250_data *data;
struct resource *regs;
int irq;
int err;
u32 val;
regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!regs)
return dev_err_probe(dev, -EINVAL, "no registers defined\n");
irq = platform_get_irq_optional(pdev, 0);
if (irq == -ENXIO)
irq = 0;
if (irq < 0)
return irq;
spin_lock_init(&p->lock);
p->mapbase = regs->start;
p->irq = irq;
p->handle_irq = dw8250_handle_irq;
p->pm = dw8250_do_pm;
p->type = PORT_8250;
p->flags = UPF_SHARE_IRQ | UPF_FIXED_PORT;
p->dev = dev;
p->iotype = UPIO_MEM;
p->serial_in = dw8250_serial_in;
p->serial_out = dw8250_serial_out;
p->set_ldisc = dw8250_set_ldisc;
p->set_termios = dw8250_set_termios;
p->membase = devm_ioremap(dev, regs->start, resource_size(regs));
if (!p->membase)
return -ENOMEM;
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->data.dma.fn = dw8250_fallback_dma_filter;
data->pdata = device_get_match_data(p->dev);
p->private_data = &data->data;
data->uart_16550_compatible = device_property_read_bool(dev,
"snps,uart-16550-compatible");
err = device_property_read_u32(dev, "reg-shift", &val);
if (!err)
p->regshift = val;
err = device_property_read_u32(dev, "reg-io-width", &val);
if (!err && val == 4) {
p->iotype = UPIO_MEM32;
p->serial_in = dw8250_serial_in32;
p->serial_out = dw8250_serial_out32;
}
if (device_property_read_bool(dev, "dcd-override")) {
data->msr_mask_on |= UART_MSR_DCD;
data->msr_mask_off |= UART_MSR_DDCD;
}
if (device_property_read_bool(dev, "dsr-override")) {
data->msr_mask_on |= UART_MSR_DSR;
data->msr_mask_off |= UART_MSR_DDSR;
}
if (device_property_read_bool(dev, "cts-override")) {
data->msr_mask_on |= UART_MSR_CTS;
data->msr_mask_off |= UART_MSR_DCTS;
}
if (device_property_read_bool(dev, "ri-override")) {
data->msr_mask_off |= UART_MSR_RI;
data->msr_mask_off |= UART_MSR_TERI;
}
device_property_read_u32(dev, "clock-frequency", &p->uartclk);
data->clk = devm_clk_get_optional(dev, "baudclk");
if (data->clk == NULL)
data->clk = devm_clk_get_optional(dev, NULL);
if (IS_ERR(data->clk))
return PTR_ERR(data->clk);
INIT_WORK(&data->clk_work, dw8250_clk_work_cb);
data->clk_notifier.notifier_call = dw8250_clk_notifier_cb;
err = clk_prepare_enable(data->clk);
if (err)
return dev_err_probe(dev, err, "could not enable optional baudclk\n");
err = devm_add_action_or_reset(dev, dw8250_clk_disable_unprepare, data->clk);
if (err)
return err;
if (data->clk)
p->uartclk = clk_get_rate(data->clk);
if (!p->uartclk)
return dev_err_probe(dev, -EINVAL, "clock rate not defined\n");
data->pclk = devm_clk_get_optional(dev, "apb_pclk");
if (IS_ERR(data->pclk))
return PTR_ERR(data->pclk);
err = clk_prepare_enable(data->pclk);
if (err)
return dev_err_probe(dev, err, "could not enable apb_pclk\n");
err = devm_add_action_or_reset(dev, dw8250_clk_disable_unprepare, data->pclk);
if (err)
return err;
data->rst = devm_reset_control_get_optional_exclusive(dev, NULL);
if (IS_ERR(data->rst))
return PTR_ERR(data->rst);
reset_control_deassert(data->rst);
err = devm_add_action_or_reset(dev, dw8250_reset_control_assert, data->rst);
if (err)
return err;
dw8250_quirks(p, data);
if (data->uart_16550_compatible)
p->handle_irq = NULL;
if (!data->skip_autocfg)
dw8250_setup_port(p);
if (p->fifosize) {
data->data.dma.rxconf.src_maxburst = p->fifosize / 4;
data->data.dma.txconf.dst_maxburst = p->fifosize / 4;
up->dma = &data->data.dma;
}
data->data.line = serial8250_register_8250_port(up);
if (data->data.line < 0)
return data->data.line;
if (data->clk) {
err = clk_notifier_register(data->clk, &data->clk_notifier);
if (err)
return dev_err_probe(dev, err, "Failed to set the clock notifier\n");
queue_work(system_unbound_wq, &data->clk_work);
}
platform_set_drvdata(pdev, data);
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
return 0;
}
static int dw8250_remove(struct platform_device *pdev)
{
struct dw8250_data *data = platform_get_drvdata(pdev);
struct device *dev = &pdev->dev;
pm_runtime_get_sync(dev);
if (data->clk) {
clk_notifier_unregister(data->clk, &data->clk_notifier);
flush_work(&data->clk_work);
}
serial8250_unregister_port(data->data.line);
pm_runtime_disable(dev);
pm_runtime_put_noidle(dev);
return 0;
}
static int dw8250_suspend(struct device *dev)
{
struct dw8250_data *data = dev_get_drvdata(dev);
serial8250_suspend_port(data->data.line);
return 0;
}
static int dw8250_resume(struct device *dev)
{
struct dw8250_data *data = dev_get_drvdata(dev);
serial8250_resume_port(data->data.line);
return 0;
}
static int dw8250_runtime_suspend(struct device *dev)
{
struct dw8250_data *data = dev_get_drvdata(dev);
clk_disable_unprepare(data->clk);
clk_disable_unprepare(data->pclk);
return 0;
}
static int dw8250_runtime_resume(struct device *dev)
{
struct dw8250_data *data = dev_get_drvdata(dev);
clk_prepare_enable(data->pclk);
clk_prepare_enable(data->clk);
return 0;
}
static const struct dev_pm_ops dw8250_pm_ops = {
SYSTEM_SLEEP_PM_OPS(dw8250_suspend, dw8250_resume)
RUNTIME_PM_OPS(dw8250_runtime_suspend, dw8250_runtime_resume, NULL)
};
static const struct dw8250_platform_data dw8250_dw_apb = {
.usr_reg = DW_UART_USR,
};
static const struct dw8250_platform_data dw8250_octeon_3860_data = {
.usr_reg = OCTEON_UART_USR,
.quirks = DW_UART_QUIRK_OCTEON,
};
static const struct dw8250_platform_data dw8250_armada_38x_data = {
.usr_reg = DW_UART_USR,
.quirks = DW_UART_QUIRK_ARMADA_38X,
};
static const struct dw8250_platform_data dw8250_renesas_rzn1_data = {
.usr_reg = DW_UART_USR,
.cpr_val = 0x00012f32,
.quirks = DW_UART_QUIRK_IS_DMA_FC,
};
static const struct dw8250_platform_data dw8250_starfive_jh7100_data = {
.usr_reg = DW_UART_USR,
.quirks = DW_UART_QUIRK_SKIP_SET_RATE,
};
static const struct of_device_id dw8250_of_match[] = {
{ .compatible = "snps,dw-apb-uart", .data = &dw8250_dw_apb },
{ .compatible = "cavium,octeon-3860-uart", .data = &dw8250_octeon_3860_data },
{ .compatible = "marvell,armada-38x-uart", .data = &dw8250_armada_38x_data },
{ .compatible = "renesas,rzn1-uart", .data = &dw8250_renesas_rzn1_data },
{ .compatible = "starfive,jh7100-uart", .data = &dw8250_starfive_jh7100_data },
{ }
};
MODULE_DEVICE_TABLE(of, dw8250_of_match);
static const struct acpi_device_id dw8250_acpi_match[] = {
{ "80860F0A", (kernel_ulong_t)&dw8250_dw_apb },
{ "8086228A", (kernel_ulong_t)&dw8250_dw_apb },
{ "AMD0020", (kernel_ulong_t)&dw8250_dw_apb },
{ "AMDI0020", (kernel_ulong_t)&dw8250_dw_apb },
{ "AMDI0022", (kernel_ulong_t)&dw8250_dw_apb },
{ "APMC0D08", (kernel_ulong_t)&dw8250_dw_apb},
{ "BRCM2032", (kernel_ulong_t)&dw8250_dw_apb },
{ "HISI0031", (kernel_ulong_t)&dw8250_dw_apb },
{ "INT33C4", (kernel_ulong_t)&dw8250_dw_apb },
{ "INT33C5", (kernel_ulong_t)&dw8250_dw_apb },
{ "INT3434", (kernel_ulong_t)&dw8250_dw_apb },
{ "INT3435", (kernel_ulong_t)&dw8250_dw_apb },
{ },
};
MODULE_DEVICE_TABLE(acpi, dw8250_acpi_match);
static struct platform_driver dw8250_platform_driver = {
.driver = {
.name = "dw-apb-uart",
.pm = pm_ptr(&dw8250_pm_ops),
.of_match_table = dw8250_of_match,
.acpi_match_table = dw8250_acpi_match,
},
.probe = dw8250_probe,
.remove = dw8250_remove,
};
module_platform_driver(dw8250_platform_driver);
MODULE_AUTHOR("Jamie Iles");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Synopsys DesignWare 8250 serial port driver");
MODULE_ALIAS("platform:dw-apb-uart"