From 090f848da000083bf6c1a052222396970e53b4d7 Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Fri, 12 Dec 2008 00:24:21 +0000 Subject: [ARM] S3C: Add UDIVSLOT support for newer UARTS Add support for the UDIVSLOT register on the newer UART blocks which gives the capability of 1/16ths adjustment to the baud rate. Signed-off-by: Ben Dooks --- drivers/serial/s3c6400.c | 1 + drivers/serial/samsung.c | 61 +++++++++++++++++++++++++++++++++++++++++++++--- drivers/serial/samsung.h | 4 ++++ 3 files changed, 63 insertions(+), 3 deletions(-) (limited to 'drivers/serial') diff --git a/drivers/serial/s3c6400.c b/drivers/serial/s3c6400.c index 06936d13393..3e378523368 100644 --- a/drivers/serial/s3c6400.c +++ b/drivers/serial/s3c6400.c @@ -102,6 +102,7 @@ static struct s3c24xx_uart_info s3c6400_uart_inf = { .name = "Samsung S3C6400 UART", .type = PORT_S3C6400, .fifosize = 64, + .has_divslot = 1, .rx_fifomask = S3C2440_UFSTAT_RXMASK, .rx_fifoshift = S3C2440_UFSTAT_RXSHIFT, .rx_fifofull = S3C2440_UFSTAT_RXFULL, diff --git a/drivers/serial/samsung.c b/drivers/serial/samsung.c index e06686ae858..93b5d75db12 100644 --- a/drivers/serial/samsung.c +++ b/drivers/serial/samsung.c @@ -508,6 +508,7 @@ s3c24xx_serial_setsource(struct uart_port *port, struct s3c24xx_uart_clksrc *c) struct baud_calc { struct s3c24xx_uart_clksrc *clksrc; unsigned int calc; + unsigned int divslot; unsigned int quot; struct clk *src; }; @@ -517,6 +518,7 @@ static int s3c24xx_serial_calcbaud(struct baud_calc *calc, struct s3c24xx_uart_clksrc *clksrc, unsigned int baud) { + struct s3c24xx_uart_port *ourport = to_ourport(port); unsigned long rate; calc->src = clk_get(port->dev, clksrc->name); @@ -527,8 +529,24 @@ static int s3c24xx_serial_calcbaud(struct baud_calc *calc, rate /= clksrc->divisor; calc->clksrc = clksrc; - calc->quot = (rate + (8 * baud)) / (16 * baud); - calc->calc = (rate / (calc->quot * 16)); + + if (ourport->info->has_divslot) { + unsigned long div = rate / baud; + + /* The UDIVSLOT register on the newer UARTs allows us to + * get a divisor adjustment of 1/16th on the baud clock. + * + * We don't keep the UDIVSLOT value (the 16ths we calculated + * by not multiplying the baud by 16) as it is easy enough + * to recalculate. + */ + + calc->quot = div / 16; + calc->calc = rate / div; + } else { + calc->quot = (rate + (8 * baud)) / (16 * baud); + calc->calc = (rate / (calc->quot * 16)); + } calc->quot--; return 1; @@ -611,6 +629,30 @@ static unsigned int s3c24xx_serial_getclk(struct uart_port *port, return best->quot; } +/* udivslot_table[] + * + * This table takes the fractional value of the baud divisor and gives + * the recommended setting for the UDIVSLOT register. + */ +static u16 udivslot_table[16] = { + [0] = 0x0000, + [1] = 0x0080, + [2] = 0x0808, + [3] = 0x0888, + [4] = 0x2222, + [5] = 0x4924, + [6] = 0x4A52, + [7] = 0x54AA, + [8] = 0x5555, + [9] = 0xD555, + [10] = 0xD5D5, + [11] = 0xDDD5, + [12] = 0xDDDD, + [13] = 0xDFDD, + [14] = 0xDFDF, + [15] = 0xFFDF, +}; + static void s3c24xx_serial_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) @@ -623,6 +665,7 @@ static void s3c24xx_serial_set_termios(struct uart_port *port, unsigned int baud, quot; unsigned int ulcon; unsigned int umcon; + unsigned int udivslot = 0; /* * We don't support modem control lines. @@ -644,6 +687,7 @@ static void s3c24xx_serial_set_termios(struct uart_port *port, /* check to see if we need to change clock source */ if (ourport->clksrc != clksrc || ourport->baudclk != clk) { + dbg("selecting clock %p\n", clk); s3c24xx_serial_setsource(port, clksrc); if (ourport->baudclk != NULL && !IS_ERR(ourport->baudclk)) { @@ -658,6 +702,13 @@ static void s3c24xx_serial_set_termios(struct uart_port *port, ourport->baudclk_rate = clk ? clk_get_rate(clk) : 0; } + if (ourport->info->has_divslot) { + unsigned int div = ourport->baudclk_rate / baud; + + udivslot = udivslot_table[div & 15]; + dbg("udivslot = %04x (div %d)\n", udivslot, div & 15); + } + switch (termios->c_cflag & CSIZE) { case CS5: dbg("config: 5bits/char\n"); @@ -697,12 +748,16 @@ static void s3c24xx_serial_set_termios(struct uart_port *port, spin_lock_irqsave(&port->lock, flags); - dbg("setting ulcon to %08x, brddiv to %d\n", ulcon, quot); + dbg("setting ulcon to %08x, brddiv to %d, udivslot %08x\n", + ulcon, quot, udivslot); wr_regl(port, S3C2410_ULCON, ulcon); wr_regl(port, S3C2410_UBRDIV, quot); wr_regl(port, S3C2410_UMCON, umcon); + if (ourport->info->has_divslot) + wr_regl(port, S3C2443_DIVSLOT, udivslot); + dbg("uart: ulcon = 0x%08x, ucon = 0x%08x, ufcon = 0x%08x\n", rd_regl(port, S3C2410_ULCON), rd_regl(port, S3C2410_UCON), diff --git a/drivers/serial/samsung.h b/drivers/serial/samsung.h index 571d6b90d20..7afb94843a0 100644 --- a/drivers/serial/samsung.h +++ b/drivers/serial/samsung.h @@ -21,6 +21,10 @@ struct s3c24xx_uart_info { unsigned long tx_fifoshift; unsigned long tx_fifofull; + /* uart port features */ + + unsigned int has_divslot:1; + /* clock source control */ int (*get_clksrc)(struct uart_port *, struct s3c24xx_uart_clksrc *clk); -- cgit v1.2.3 From fd1e6c1df5c396961509daac2b456852edf982df Mon Sep 17 00:00:00 2001 From: Breno Leitao Date: Wed, 6 May 2009 17:17:57 +0100 Subject: jsm: removing unused spinlock This patch removes bd_lock spinlock (inside jsm_board structure). The lock is initialized in the probe function and not used anymore. Signed-off-by: Breno Leitao Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- drivers/serial/jsm/jsm.h | 2 -- drivers/serial/jsm/jsm_driver.c | 1 - 2 files changed, 3 deletions(-) (limited to 'drivers/serial') diff --git a/drivers/serial/jsm/jsm.h b/drivers/serial/jsm/jsm.h index 8871aaa3dba..c0a3e2734e2 100644 --- a/drivers/serial/jsm/jsm.h +++ b/drivers/serial/jsm/jsm.h @@ -130,8 +130,6 @@ struct jsm_board struct pci_dev *pci_dev; u32 maxports; /* MAX ports this board can handle */ - spinlock_t bd_lock; /* Used to protect board */ - spinlock_t bd_intr_lock; /* Used to protect the poller tasklet and * the interrupt routine from each other. */ diff --git a/drivers/serial/jsm/jsm_driver.c b/drivers/serial/jsm/jsm_driver.c index d2d32a19862..b3604aa322a 100644 --- a/drivers/serial/jsm/jsm_driver.c +++ b/drivers/serial/jsm/jsm_driver.c @@ -88,7 +88,6 @@ static int __devinit jsm_probe_one(struct pci_dev *pdev, const struct pci_device else brd->maxports = 2; - spin_lock_init(&brd->bd_lock); spin_lock_init(&brd->bd_intr_lock); /* store which revision we have */ -- cgit v1.2.3 From 951c4df5b7703137bf4eee002d98d083fbc890cc Mon Sep 17 00:00:00 2001 From: Benjamin Krill Date: Wed, 13 May 2009 05:56:54 +0000 Subject: serial/nwpserial: Fix wrong register read address and add interrupt acknowledge. The receive interrupt routine checks the wrong register if the receive fifo is empty. Further an explicit interrupt acknowledge write is introduced. In some circumstances another interrupt was issued. Signed-off-by: Benjamin Krill Signed-off-by: Arnd Bergmann Signed-off-by: Benjamin Herrenschmidt --- drivers/serial/nwpserial.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/serial') diff --git a/drivers/serial/nwpserial.c b/drivers/serial/nwpserial.c index 32f3eaf0d26..9e150b19d72 100644 --- a/drivers/serial/nwpserial.c +++ b/drivers/serial/nwpserial.c @@ -145,11 +145,13 @@ static irqreturn_t nwpserial_interrupt(int irq, void *dev_id) ch = dcr_read(up->dcr_host, UART_RX); if (up->port.ignore_status_mask != NWPSERIAL_STATUS_RXVALID) tty_insert_flip_char(tty, ch, TTY_NORMAL); - } while (dcr_read(up->dcr_host, UART_RX) & UART_LSR_DR); + } while (dcr_read(up->dcr_host, UART_LSR) & UART_LSR_DR); tty_flip_buffer_push(tty); ret = IRQ_HANDLED; + /* clear interrupt */ + dcr_write(up->dcr_host, UART_IIR, 1); out: spin_unlock(&up->port.lock); return ret; -- cgit v1.2.3