* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <linux/clk.h>
#include <linux/console.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#define OWL_UART_PORT_NUM 7
+#define OWL_UART_DEV_NAME "ttyOWL"
#define OWL_UART_CTL 0x000
+#define OWL_UART_RXDAT 0x004
#define OWL_UART_TXDAT 0x008
#define OWL_UART_STAT 0x00c
+#define OWL_UART_CTL_DWLS_MASK GENMASK(1, 0)
+#define OWL_UART_CTL_DWLS_5BITS (0x0 << 0)
+#define OWL_UART_CTL_DWLS_6BITS (0x1 << 0)
+#define OWL_UART_CTL_DWLS_7BITS (0x2 << 0)
+#define OWL_UART_CTL_DWLS_8BITS (0x3 << 0)
+#define OWL_UART_CTL_STPS_2BITS BIT(2)
+#define OWL_UART_CTL_PRS_MASK GENMASK(6, 4)
+#define OWL_UART_CTL_PRS_NONE (0x0 << 4)
+#define OWL_UART_CTL_PRS_ODD (0x4 << 4)
+#define OWL_UART_CTL_PRS_MARK (0x5 << 4)
+#define OWL_UART_CTL_PRS_EVEN (0x6 << 4)
+#define OWL_UART_CTL_PRS_SPACE (0x7 << 4)
+#define OWL_UART_CTL_AFE BIT(12)
#define OWL_UART_CTL_TRFS_TX BIT(14)
#define OWL_UART_CTL_EN BIT(15)
+#define OWL_UART_CTL_RXDE BIT(16)
+#define OWL_UART_CTL_TXDE BIT(17)
#define OWL_UART_CTL_RXIE BIT(18)
#define OWL_UART_CTL_TXIE BIT(19)
+#define OWL_UART_CTL_LBEN BIT(20)
#define OWL_UART_STAT_RIP BIT(0)
#define OWL_UART_STAT_TIP BIT(1)
+#define OWL_UART_STAT_RXER BIT(2)
+#define OWL_UART_STAT_TFER BIT(3)
+#define OWL_UART_STAT_RXST BIT(4)
+#define OWL_UART_STAT_RFEM BIT(5)
#define OWL_UART_STAT_TFFU BIT(6)
-#define OWL_UART_STAT_TRFL_MASK (0x1f << 11)
+#define OWL_UART_STAT_CTSS BIT(7)
+#define OWL_UART_STAT_RTSS BIT(8)
+#define OWL_UART_STAT_TFES BIT(10)
+#define OWL_UART_STAT_TRFL_MASK GENMASK(16, 11)
#define OWL_UART_STAT_UTBB BIT(17)
+static struct uart_driver owl_uart_driver;
+
+struct owl_uart_info {
+ unsigned int tx_fifosize;
+};
+
+struct owl_uart_port {
+ struct uart_port port;
+ struct clk *clk;
+};
+
+#define to_owl_uart_port(prt) container_of(prt, struct owl_uart_port, prt)
+
+static struct owl_uart_port *owl_uart_ports[OWL_UART_PORT_NUM];
+
static inline void owl_uart_write(struct uart_port *port, u32 val, unsigned int off)
{
writel(val, port->membase + off);
return readl(port->membase + off);
}
+static void owl_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+ u32 ctl;
+
+ ctl = owl_uart_read(port, OWL_UART_CTL);
+
+ if (mctrl & TIOCM_LOOP)
+ ctl |= OWL_UART_CTL_LBEN;
+ else
+ ctl &= ~OWL_UART_CTL_LBEN;
+
+ owl_uart_write(port, ctl, OWL_UART_CTL);
+}
+
+static unsigned int owl_uart_get_mctrl(struct uart_port *port)
+{
+ unsigned int mctrl = TIOCM_CAR | TIOCM_DSR;
+ u32 stat, ctl;
+
+ ctl = owl_uart_read(port, OWL_UART_CTL);
+ stat = owl_uart_read(port, OWL_UART_STAT);
+ if (stat & OWL_UART_STAT_RTSS)
+ mctrl |= TIOCM_RTS;
+ if ((stat & OWL_UART_STAT_CTSS) || !(ctl & OWL_UART_CTL_AFE))
+ mctrl |= TIOCM_CTS;
+ return mctrl;
+}
+
+static unsigned int owl_uart_tx_empty(struct uart_port *port)
+{
+ unsigned long flags;
+ u32 val;
+ unsigned int ret;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ val = owl_uart_read(port, OWL_UART_STAT);
+ ret = (val & OWL_UART_STAT_TFES) ? TIOCSER_TEMT : 0;
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ return ret;
+}
+
+static void owl_uart_stop_rx(struct uart_port *port)
+{
+ u32 val;
+
+ val = owl_uart_read(port, OWL_UART_CTL);
+ val &= ~(OWL_UART_CTL_RXIE | OWL_UART_CTL_RXDE);
+ owl_uart_write(port, val, OWL_UART_CTL);
+
+ val = owl_uart_read(port, OWL_UART_STAT);
+ val |= OWL_UART_STAT_RIP;
+ owl_uart_write(port, val, OWL_UART_STAT);
+}
+
+static void owl_uart_stop_tx(struct uart_port *port)
+{
+ u32 val;
+
+ val = owl_uart_read(port, OWL_UART_CTL);
+ val &= ~(OWL_UART_CTL_TXIE | OWL_UART_CTL_TXDE);
+ owl_uart_write(port, val, OWL_UART_CTL);
+
+ val = owl_uart_read(port, OWL_UART_STAT);
+ val |= OWL_UART_STAT_TIP;
+ owl_uart_write(port, val, OWL_UART_STAT);
+}
+
+static void owl_uart_start_tx(struct uart_port *port)
+{
+ u32 val;
+
+ if (uart_tx_stopped(port)) {
+ owl_uart_stop_tx(port);
+ return;
+ }
+
+ val = owl_uart_read(port, OWL_UART_STAT);
+ val |= OWL_UART_STAT_TIP;
+ owl_uart_write(port, val, OWL_UART_STAT);
+
+ val = owl_uart_read(port, OWL_UART_CTL);
+ val |= OWL_UART_CTL_TXIE;
+ owl_uart_write(port, val, OWL_UART_CTL);
+}
+
+static void owl_uart_send_chars(struct uart_port *port)
+{
+ struct circ_buf *xmit = &port->state->xmit;
+ unsigned int ch;
+
+ if (uart_tx_stopped(port))
+ return;
+
+ if (port->x_char) {
+ while (!(owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU))
+ cpu_relax();
+ owl_uart_write(port, port->x_char, OWL_UART_TXDAT);
+ port->icount.tx++;
+ port->x_char = 0;
+ }
+
+ while (!(owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU)) {
+ if (uart_circ_empty(xmit))
+ break;
+
+ ch = xmit->buf[xmit->tail];
+ owl_uart_write(port, ch, OWL_UART_TXDAT);
+ xmit->tail = (xmit->tail + 1) & (SERIAL_XMIT_SIZE - 1);
+ port->icount.tx++;
+ }
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(port);
+
+ if (uart_circ_empty(xmit))
+ owl_uart_stop_tx(port);
+}
+
+static void owl_uart_receive_chars(struct uart_port *port)
+{
+ u32 stat, val;
+
+ val = owl_uart_read(port, OWL_UART_CTL);
+ val &= ~OWL_UART_CTL_TRFS_TX;
+ owl_uart_write(port, val, OWL_UART_CTL);
+
+ stat = owl_uart_read(port, OWL_UART_STAT);
+ while (!(stat & OWL_UART_STAT_RFEM)) {
+ char flag = TTY_NORMAL;
+
+ if (stat & OWL_UART_STAT_RXER)
+ port->icount.overrun++;
+
+ if (stat & OWL_UART_STAT_RXST) {
+ /* We are not able to distinguish the error type. */
+ port->icount.brk++;
+ port->icount.frame++;
+
+ stat &= port->read_status_mask;
+ if (stat & OWL_UART_STAT_RXST)
+ flag = TTY_PARITY;
+ } else
+ port->icount.rx++;
+
+ val = owl_uart_read(port, OWL_UART_RXDAT);
+ val &= 0xff;
+
+ if ((stat & port->ignore_status_mask) == 0)
+ tty_insert_flip_char(&port->state->port, val, flag);
+
+ stat = owl_uart_read(port, OWL_UART_STAT);
+ }
+
+ spin_unlock(&port->lock);
+ tty_flip_buffer_push(&port->state->port);
+ spin_lock(&port->lock);
+}
+
+static irqreturn_t owl_uart_irq(int irq, void *dev_id)
+{
+ struct uart_port *port = dev_id;
+ unsigned long flags;
+ u32 stat;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ stat = owl_uart_read(port, OWL_UART_STAT);
+
+ if (stat & OWL_UART_STAT_RIP)
+ owl_uart_receive_chars(port);
+
+ if (stat & OWL_UART_STAT_TIP)
+ owl_uart_send_chars(port);
+
+ stat = owl_uart_read(port, OWL_UART_STAT);
+ stat |= OWL_UART_STAT_RIP | OWL_UART_STAT_TIP;
+ owl_uart_write(port, stat, OWL_UART_STAT);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ return IRQ_HANDLED;
+}
+
+static void owl_uart_shutdown(struct uart_port *port)
+{
+ u32 val;
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ val = owl_uart_read(port, OWL_UART_CTL);
+ val &= ~(OWL_UART_CTL_TXIE | OWL_UART_CTL_RXIE
+ | OWL_UART_CTL_TXDE | OWL_UART_CTL_RXDE | OWL_UART_CTL_EN);
+ owl_uart_write(port, val, OWL_UART_CTL);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ free_irq(port->irq, port);
+}
+
+static int owl_uart_startup(struct uart_port *port)
+{
+ u32 val;
+ unsigned long flags;
+ int ret;
+
+ ret = request_irq(port->irq, owl_uart_irq, IRQF_TRIGGER_HIGH,
+ "owl-uart", port);
+ if (ret)
+ return ret;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ val = owl_uart_read(port, OWL_UART_STAT);
+ val |= OWL_UART_STAT_RIP | OWL_UART_STAT_TIP
+ | OWL_UART_STAT_RXER | OWL_UART_STAT_TFER | OWL_UART_STAT_RXST;
+ owl_uart_write(port, val, OWL_UART_STAT);
+
+ val = owl_uart_read(port, OWL_UART_CTL);
+ val |= OWL_UART_CTL_RXIE | OWL_UART_CTL_TXIE;
+ val |= OWL_UART_CTL_EN;
+ owl_uart_write(port, val, OWL_UART_CTL);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ return 0;
+}
+
+static void owl_uart_change_baudrate(struct owl_uart_port *owl_port,
+ unsigned long baud)
+{
+ clk_set_rate(owl_port->clk, baud * 8);
+}
+
+static void owl_uart_set_termios(struct uart_port *port,
+ struct ktermios *termios,
+ struct ktermios *old)
+{
+ struct owl_uart_port *owl_port = to_owl_uart_port(port);
+ unsigned int baud;
+ u32 ctl;
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ ctl = owl_uart_read(port, OWL_UART_CTL);
+
+ ctl &= ~OWL_UART_CTL_DWLS_MASK;
+ switch (termios->c_cflag & CSIZE) {
+ case CS5:
+ ctl |= OWL_UART_CTL_DWLS_5BITS;
+ break;
+ case CS6:
+ ctl |= OWL_UART_CTL_DWLS_6BITS;
+ break;
+ case CS7:
+ ctl |= OWL_UART_CTL_DWLS_7BITS;
+ break;
+ case CS8:
+ default:
+ ctl |= OWL_UART_CTL_DWLS_8BITS;
+ break;
+ }
+
+ if (termios->c_cflag & CSTOPB)
+ ctl |= OWL_UART_CTL_STPS_2BITS;
+ else
+ ctl &= ~OWL_UART_CTL_STPS_2BITS;
+
+ ctl &= ~OWL_UART_CTL_PRS_MASK;
+ if (termios->c_cflag & PARENB) {
+ if (termios->c_cflag & CMSPAR) {
+ if (termios->c_cflag & PARODD)
+ ctl |= OWL_UART_CTL_PRS_MARK;
+ else
+ ctl |= OWL_UART_CTL_PRS_SPACE;
+ } else if (termios->c_cflag & PARODD)
+ ctl |= OWL_UART_CTL_PRS_ODD;
+ else
+ ctl |= OWL_UART_CTL_PRS_EVEN;
+ } else
+ ctl |= OWL_UART_CTL_PRS_NONE;
+
+ if (termios->c_cflag & CRTSCTS)
+ ctl |= OWL_UART_CTL_AFE;
+ else
+ ctl &= ~OWL_UART_CTL_AFE;
+
+ owl_uart_write(port, ctl, OWL_UART_CTL);
+
+ baud = uart_get_baud_rate(port, termios, old, 9600, 3200000);
+ owl_uart_change_baudrate(owl_port, baud);
+
+ /* Don't rewrite B0 */
+ if (tty_termios_baud_rate(termios))
+ tty_termios_encode_baud_rate(termios, baud, baud);
+
+ port->read_status_mask |= OWL_UART_STAT_RXER;
+ if (termios->c_iflag & INPCK)
+ port->read_status_mask |= OWL_UART_STAT_RXST;
+
+ uart_update_timeout(port, termios->c_cflag, baud);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void owl_uart_release_port(struct uart_port *port)
+{
+ struct platform_device *pdev = to_platform_device(port->dev);
+ struct resource *res;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return;
+
+ if (port->flags & UPF_IOREMAP) {
+ devm_release_mem_region(port->dev, port->mapbase,
+ resource_size(res));
+ devm_iounmap(port->dev, port->membase);
+ port->membase = NULL;
+ }
+}
+
+static int owl_uart_request_port(struct uart_port *port)
+{
+ struct platform_device *pdev = to_platform_device(port->dev);
+ struct resource *res;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENXIO;
+
+ if (!devm_request_mem_region(port->dev, port->mapbase,
+ resource_size(res), dev_name(port->dev)))
+ return -EBUSY;
+
+ if (port->flags & UPF_IOREMAP) {
+ port->membase = devm_ioremap_nocache(port->dev, port->mapbase,
+ resource_size(res));
+ if (!port->membase)
+ return -EBUSY;
+ }
+
+ return 0;
+}
+
+static const char *owl_uart_type(struct uart_port *port)
+{
+ return (port->type == PORT_OWL) ? "owl-uart" : NULL;
+}
+
+static int owl_uart_verify_port(struct uart_port *port,
+ struct serial_struct *ser)
+{
+ if (port->type != PORT_OWL)
+ return -EINVAL;
+
+ if (port->irq != ser->irq)
+ return -EINVAL;
+
+ return 0;
+}
+
+static void owl_uart_config_port(struct uart_port *port, int flags)
+{
+ if (flags & UART_CONFIG_TYPE) {
+ port->type = PORT_OWL;
+ owl_uart_request_port(port);
+ }
+}
+
+static struct uart_ops owl_uart_ops = {
+ .set_mctrl = owl_uart_set_mctrl,
+ .get_mctrl = owl_uart_get_mctrl,
+ .tx_empty = owl_uart_tx_empty,
+ .start_tx = owl_uart_start_tx,
+ .stop_rx = owl_uart_stop_rx,
+ .stop_tx = owl_uart_stop_tx,
+ .startup = owl_uart_startup,
+ .shutdown = owl_uart_shutdown,
+ .set_termios = owl_uart_set_termios,
+ .type = owl_uart_type,
+ .config_port = owl_uart_config_port,
+ .request_port = owl_uart_request_port,
+ .release_port = owl_uart_release_port,
+ .verify_port = owl_uart_verify_port,
+};
+
#ifdef CONFIG_SERIAL_OWL_CONSOLE
static void owl_console_putchar(struct uart_port *port, int ch)
local_irq_restore(flags);
}
+static void owl_uart_console_write(struct console *co, const char *s,
+ u_int count)
+{
+ struct owl_uart_port *owl_port;
+
+ owl_port = owl_uart_ports[co->index];
+ if (!owl_port)
+ return;
+
+ owl_uart_port_write(&owl_port->port, s, count);
+}
+
+static int owl_uart_console_setup(struct console *co, char *options)
+{
+ struct owl_uart_port *owl_port;
+ int baud = 115200;
+ int bits = 8;
+ int parity = 'n';
+ int flow = 'n';
+
+ if (co->index < 0 || co->index >= OWL_UART_PORT_NUM)
+ return -EINVAL;
+
+ owl_port = owl_uart_ports[co->index];
+ if (!owl_port || !owl_port->port.membase)
+ return -ENODEV;
+
+ if (options)
+ uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+ return uart_set_options(&owl_port->port, co, baud, parity, bits, flow);
+}
+
+static struct console owl_uart_console = {
+ .name = OWL_UART_DEV_NAME,
+ .write = owl_uart_console_write,
+ .device = uart_console_device,
+ .setup = owl_uart_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+ .data = &owl_uart_driver,
+};
+
+static int __init owl_uart_console_init(void)
+{
+ register_console(&owl_uart_console);
+
+ return 0;
+}
+console_initcall(owl_uart_console_init);
+
static void owl_uart_early_console_write(struct console *co,
const char *s,
u_int count)
OF_EARLYCON_DECLARE(owl, "actions,owl-uart",
owl_uart_early_console_setup);
-#endif /* CONFIG_SERIAL_OWL_CONSOLE */
+#define OWL_UART_CONSOLE (&owl_uart_console)
+#else
+#define OWL_UART_CONSOLE NULL
+#endif
+
+static struct uart_driver owl_uart_driver = {
+ .owner = THIS_MODULE,
+ .driver_name = "owl-uart",
+ .dev_name = OWL_UART_DEV_NAME,
+ .nr = OWL_UART_PORT_NUM,
+ .cons = OWL_UART_CONSOLE,
+};
+
+static const struct owl_uart_info owl_s500_info = {
+ .tx_fifosize = 16,
+};
+
+static const struct owl_uart_info owl_s900_info = {
+ .tx_fifosize = 32,
+};
+
+static const struct of_device_id owl_uart_dt_matches[] = {
+ { .compatible = "actions,s500-uart", .data = &owl_s500_info },
+ { .compatible = "actions,s900-uart", .data = &owl_s900_info },
+ { }
+};
+MODULE_DEVICE_TABLE(of, owl_uart_dt_matches);
+
+static int owl_uart_probe(struct platform_device *pdev)
+{
+ const struct of_device_id *match;
+ const struct owl_uart_info *info = NULL;
+ struct resource *res_mem;
+ struct owl_uart_port *owl_port;
+ int ret, irq;
+
+ if (pdev->dev.of_node) {
+ pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
+ match = of_match_node(owl_uart_dt_matches, pdev->dev.of_node);
+ if (match)
+ info = match->data;
+ }
+
+ if (pdev->id < 0 || pdev->id >= OWL_UART_PORT_NUM) {
+ dev_err(&pdev->dev, "id %d out of range\n", pdev->id);
+ return -EINVAL;
+ }
+
+ res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res_mem) {
+ dev_err(&pdev->dev, "could not get mem\n");
+ return -ENODEV;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "could not get irq\n");
+ return irq;
+ }
+
+ if (owl_uart_ports[pdev->id]) {
+ dev_err(&pdev->dev, "port %d already allocated\n", pdev->id);
+ return -EBUSY;
+ }
+
+ owl_port = devm_kzalloc(&pdev->dev, sizeof(*owl_port), GFP_KERNEL);
+ if (!owl_port)
+ return -ENOMEM;
+
+ owl_port->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(owl_port->clk)) {
+ dev_err(&pdev->dev, "could not get clk\n");
+ return PTR_ERR(owl_port->clk);
+ }
+
+ owl_port->port.dev = &pdev->dev;
+ owl_port->port.line = pdev->id;
+ owl_port->port.type = PORT_OWL;
+ owl_port->port.iotype = UPIO_MEM;
+ owl_port->port.mapbase = res_mem->start;
+ owl_port->port.irq = irq;
+ owl_port->port.uartclk = clk_get_rate(owl_port->clk);
+ if (owl_port->port.uartclk == 0) {
+ dev_err(&pdev->dev, "clock rate is zero\n");
+ return -EINVAL;
+ }
+ owl_port->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP | UPF_LOW_LATENCY;
+ owl_port->port.x_char = 0;
+ owl_port->port.fifosize = (info) ? info->tx_fifosize : 16;
+ owl_port->port.ops = &owl_uart_ops;
+
+ owl_uart_ports[pdev->id] = owl_port;
+ platform_set_drvdata(pdev, owl_port);
+
+ ret = uart_add_one_port(&owl_uart_driver, &owl_port->port);
+ if (ret)
+ owl_uart_ports[pdev->id] = NULL;
+
+ return ret;
+}
+
+static int owl_uart_remove(struct platform_device *pdev)
+{
+ struct owl_uart_port *owl_port = platform_get_drvdata(pdev);
+
+ uart_remove_one_port(&owl_uart_driver, &owl_port->port);
+ owl_uart_ports[pdev->id] = NULL;
+
+ return 0;
+}
+
+static struct platform_driver owl_uart_platform_driver = {
+ .probe = owl_uart_probe,
+ .remove = owl_uart_remove,
+ .driver = {
+ .name = "owl-uart",
+ .of_match_table = owl_uart_dt_matches,
+ },
+};
+
+static int __init owl_uart_init(void)
+{
+ int ret;
+
+ ret = uart_register_driver(&owl_uart_driver);
+ if (ret)
+ return ret;
+
+ ret = platform_driver_register(&owl_uart_platform_driver);
+ if (ret)
+ uart_unregister_driver(&owl_uart_driver);
+
+ return ret;
+}
+
+static void __init owl_uart_exit(void)
+{
+ platform_driver_unregister(&owl_uart_platform_driver);
+ uart_unregister_driver(&owl_uart_driver);
+}
+
+module_init(owl_uart_init);
+module_exit(owl_uart_exit);
+
+MODULE_LICENSE("GPL");
projects / platform / kernel / linux-starfive.git / commitdiff