EG20T: Update PCH_UART driver to 2.6.36

Hi Alan,

I have modified for your indications.
(As to details, please refer previous my response mail) Please check below.

drivers/serial/pch_uart.c new file +7 -0

+#include <linux/interrupt.h>
+#include <linux/io.h>
+
+#ifdef CONFIG_PCH_DMA
+#include <linux/dmaengine.h>
+#include <linux/pch_dma.h>
+#endif

You do not need this ifdef. Even if you are not using the DMA feature it will still compile. DMA/non-DMA needs to be runtime. See below

drivers/serial/pch_uart.c new file +15 -0

+enum {
+ PCH_UART_HAL_INVALID_PARAM = EINVAL,
+ PCH_UART_HAL_NOT_INITIALIZED = 256,
+ PCH_UART_HAL_NOT_REQUESTED,
+ PCH_UART_HAL_BASE_NOT_SET,
+ PCH_UART_HAL_INVALID_BAUD,
+ PCH_UART_HAL_INVALID_PARITY,
+ PCH_UART_HAL_INVALID_WLS,
+ PCH_UART_HAL_INVALID_FIFO_CLR,
+ PCH_UART_HAL_INVALID_DMAMODE,
+ PCH_UART_HAL_INVALID_FIFOSIZE,
+ PCH_UART_HAL_INVALID_TRIGGER,
+ PCH_UART_HAL_INVALID_STB,
+ PCH_UART_HAL_READ_ERROR,
+};

These should be replaced with ordinary Linux error codes in the functions.

drivers/serial/pch_uart.c new file +38 -0

+struct eg20t_port {
+ struct uart_port port;
+ int port_type;
+ void __iomem *membase;
+ resource_size_t mapbase;
+ unsigned int iobase;
+ struct pci_dev *pdev;
+ int fifo_size;
+ int base_baud;
+ int start_tx;
+ int start_rx;
+ int tx_empty;
+ int int_dis_flag;
+ int trigger;
+ int trigger_level;
+ struct pch_uart_buffer rxbuf;
+ unsigned int dmsr;
+ unsigned int fcr;
+#ifdef CONFIG_PCH_DMA
+ struct dma_async_tx_descriptor *desc_tx;
+ struct dma_async_tx_descriptor *desc_rx;
+ struct pch_dma_slave param_tx;
+ struct pch_dma_slave param_rx;
+ struct dma_chan *chan_tx;
+ struct dma_chan *chan_rx;
+ struct scatterlist sg_tx;
+ struct scatterlist sg_rx;
+ int tx_dma_use;
+ void *rx_buf_virt;
+ dma_addr_t rx_buf_dma;
+#endif
+};
 
+static unsigned int get_msr(struct eg20t_port *priv, void __iomem *base)
+{
+ unsigned int msr = ioread8(base + PCH_UART_MSR);
+ priv->dmsr |= msr & PCH_UART_MSR_DELTA;
+
+ return msr;

msr should be a u8 ? Is there a reason priv->dmsr is unsigned int ?

drivers/serial/pch_uart.c new file +7 -0

+static void pch_uart_hal_enable_interrupt(struct eg20t_port *priv,
+   unsigned int flag)
+{
+ unsigned int ier = ioread8(priv->membase + PCH_UART_IER);
+ ier |= flag & PCH_UART_IER_MASK;
+ iowrite8(ier, priv->membase + PCH_UART_IER);
+}

Same for ier and fcr ?

drivers/serial/pch_uart.c new file +13 -0

+static int pch_uart_hal_read(struct eg20t_port *priv, unsigned char *buf,
+      int rx_size)
+{
+ int i;
+ unsigned int rbr, lsr;
+
+ lsr = ioread8(priv->membase + PCH_UART_LSR);
+ for (i = 0, lsr = ioread8(priv->membase + PCH_UART_LSR);
+      i < rx_size && lsr & PCH_UART_LSR_DR;
+      lsr = ioread8(priv->membase + PCH_UART_LSR)) {
+ rbr = ioread8(priv->membase + PCH_UART_RBR);
+ buf[i++] = (unsigned char)rbr;
+ }

Same again here - which would also lose the cast

drivers/serial/pch_uart.c new file +7 -0

+static int pch_uart_hal_get_line_status(struct eg20t_port *priv)
+{
+ unsigned int lsr;
+ int ret;
+
+ lsr = ioread8(priv->membase + PCH_UART_LSR);
+ ret = (int)lsr;

And here

drivers/serial/pch_uart.c new file +15 -0

+static int push_rx(struct eg20t_port *priv, const unsigned char *buf,
+    int size)
+{
+ struct uart_port *port;
+ struct tty_struct *tty;
+ int sz, i, j;
+ int loop;
+ int pushed;
+
+ port = &priv->port;
+ tty = tty_port_tty_get(&port->state->port);
+ if (!tty) {
+ pr_info("%s:tty is busy now", __func__);
+ return -EBUSY;
+ }

Don't log this. It is a perfectly normal situation - no pr_info needed (pr_debug if testing perhaps)

drivers/serial/pch_uart.c new file +12 -0

+
+ for (pushed = 0, i = 0, loop = 1; (pushed < size) && loop;
+      pushed += sz, i++) {
+ sz = tty_insert_flip_string(tty, &buf[pushed], size - pushed);
+ for (j = 0; (j < 100000) && (sz == 0); j++) {
+ tty_flip_buffer_push(tty);
+ sz = tty_insert_flip_string(tty, &buf[pushed],
+     size - pushed);
+ }
+ if (sz == 0)
+ loop = 0;
+ }

This should not be needed. tty_insert_flip_string tries to insert as much as it can. Except when tty->low_latency is set, which requires the call is not from an interrupt handler the flip_buffer_push will queue data to the line discipline it will not make space.

+ room = tty_buffer_request_room(tty, size);

drivers/serial/pch_uart.c new file +11 -0

+
+ if (room < size)
+ dev_warn(port->dev, "Rx overrun: dropping %u bytes\n",
+ size - room);
+ if (!room)
+ return room;
+
+ for (i = 0; i < room; i++) {
+ tty_insert_flip_char(tty, ((u8 *)sg_virt(&priv->sg_rx))[i],
+      TTY_NORMAL);
+ }

You can replace all of that with a single call to tty_insert_flip_string ?

+ struct tty_struct *tty = tty_port_tty_get(&port->state->port);
+ if (!tty) {
+ pr_info("%s:tty is busy now", __func__);

Again don't log this.

drivers/serial/pch_uart.c new file +3 -0

+static void pch_uart_send_xchar(struct uart_port *port, char ch)
+{
+}

??

+ ret = pch_uart_hal_set_fifo(priv, PCH_UART_HAL_DMA_MODE0,
+ fifo_size, priv->trigger);

Is this missing check intentional ?

drivers/serial/pch_uart.c new file +11 -0

+
+ ret = request_irq(priv->port.irq, pch_uart_interrupt, IRQF_SHARED,
+ KBUILD_MODNAME, priv);
+
+ if (ret < 0)
+ return ret;
 
 
+static int pch_uart_verify_port(struct uart_port *port,
+                               struct serial_struct *serinfo)
+{
+       return 0;
+}

As you don't support low latency you want to do

static int pch_uart_verify_port(struct uart_port *port,
struct serial_struct *serinfo)
{
if (serinfo->flags & UPF_LOW_LATENCY)
return -EOPNOTSUPP;
return 0;
}

(A few other drivers also miss this)

What you could also consider doing is

static int pch_uart_verify_port(struct uart_port *port,
struct serial_struct *serinfo)
{
if (serinfo->flags & UPF_LOW_LATENCY)
use_pio_modes;
/* Avoid tty->low_latency being set as we do not support it */ serinfo->flags &= ~UPF_LOW_LATENCY;
} else
use_dma_modes;
return 0;
}

I think that would make "setserial /dev/ttyPCH0 low_latency" select PIO and the reverse "setserial /dev/ttyPCH0 ^low_latency" select DMA mode but it would need testing to make sure that it is all that is needed.