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Commit 4b967e63 authored by Rahul Tanwar's avatar Rahul Tanwar Committed by Greg Kroah-Hartman
Browse files

serial: lantiq: Add SMP support 



The existing driver can only support single core SoC. But new multicore
platforms which reuse the same driver/IP need SMP support. This patch adds
multicore support in the driver.

Signed-off-by: default avatarRahul Tanwar <rahul.tanwar@linux.intel.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@intel.com>
Link: https://lore.kernel.org/r/7912786cccad60c72b20ea724af1def505ab22aa.1565160764.git.rahul.tanwar@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 6798e901

drivers/tty/serial/lantiq.c

+32 −15
Original line number Diff line number Diff line
@@ -99,7 +99,6 @@ 
static void lqasc_tx_chars(struct uart_port *port);

static struct ltq_uart_port *lqasc_port[MAXPORTS];

static struct uart_driver lqasc_reg;

static DEFINE_SPINLOCK(ltq_asc_lock);



struct ltq_uart_port {

	struct uart_port	port;
@@ -110,6 +109,7 @@ struct ltq_uart_port { 
	unsigned int		tx_irq;

	unsigned int		rx_irq;

	unsigned int		err_irq;

	spinlock_t		lock; /* exclusive access for multi core */

};



static inline void asc_update_bits(u32 clear, u32 set, void __iomem *reg)
@@ -135,9 +135,11 @@ static void 
lqasc_start_tx(struct uart_port *port)

{

	unsigned long flags;

	spin_lock_irqsave(&ltq_asc_lock, flags);

	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);



	spin_lock_irqsave(&ltq_port->lock, flags);

	lqasc_tx_chars(port);

	spin_unlock_irqrestore(&ltq_asc_lock, flags);

	spin_unlock_irqrestore(&ltq_port->lock, flags);

	return;

}
@@ -245,9 +247,11 @@ lqasc_tx_int(int irq, void *_port) 
{

	unsigned long flags;

	struct uart_port *port = (struct uart_port *)_port;

	spin_lock_irqsave(&ltq_asc_lock, flags);

	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);



	spin_lock_irqsave(&ltq_port->lock, flags);

	__raw_writel(ASC_IRNCR_TIR, port->membase + LTQ_ASC_IRNCR);

	spin_unlock_irqrestore(&ltq_asc_lock, flags);

	spin_unlock_irqrestore(&ltq_port->lock, flags);

	lqasc_start_tx(port);

	return IRQ_HANDLED;

}
@@ -257,11 +261,13 @@ lqasc_err_int(int irq, void *_port) 
{

	unsigned long flags;

	struct uart_port *port = (struct uart_port *)_port;

	spin_lock_irqsave(&ltq_asc_lock, flags);

	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);



	spin_lock_irqsave(&ltq_port->lock, flags);

	/* clear any pending interrupts */

	asc_update_bits(0, ASCWHBSTATE_CLRPE | ASCWHBSTATE_CLRFE |

		ASCWHBSTATE_CLRROE, port->membase + LTQ_ASC_WHBSTATE);

	spin_unlock_irqrestore(&ltq_asc_lock, flags);

	spin_unlock_irqrestore(&ltq_port->lock, flags);

	return IRQ_HANDLED;

}
@@ -270,10 +276,12 @@ lqasc_rx_int(int irq, void *_port) 
{

	unsigned long flags;

	struct uart_port *port = (struct uart_port *)_port;

	spin_lock_irqsave(&ltq_asc_lock, flags);

	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);



	spin_lock_irqsave(&ltq_port->lock, flags);

	__raw_writel(ASC_IRNCR_RIR, port->membase + LTQ_ASC_IRNCR);

	lqasc_rx_chars(port);

	spin_unlock_irqrestore(&ltq_asc_lock, flags);

	spin_unlock_irqrestore(&ltq_port->lock, flags);

	return IRQ_HANDLED;

}
@@ -307,11 +315,13 @@ lqasc_startup(struct uart_port *port) 
{

	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);

	int retval;

	unsigned long flags;



	if (!IS_ERR(ltq_port->clk))

		clk_prepare_enable(ltq_port->clk);

	port->uartclk = clk_get_rate(ltq_port->freqclk);



	spin_lock_irqsave(&ltq_port->lock, flags);

	asc_update_bits(ASCCLC_DISS | ASCCLC_RMCMASK, (1 << ASCCLC_RMCOFFSET),

		port->membase + LTQ_ASC_CLC);
@@ -331,6 +341,8 @@ lqasc_startup(struct uart_port *port) 
	asc_update_bits(0, ASCCON_M_8ASYNC | ASCCON_FEN | ASCCON_TOEN |

		ASCCON_ROEN, port->membase + LTQ_ASC_CON);



	spin_unlock_irqrestore(&ltq_port->lock, flags);



	retval = request_irq(ltq_port->tx_irq, lqasc_tx_int,

		0, "asc_tx", port);

	if (retval) {
@@ -367,15 +379,19 @@ static void 
lqasc_shutdown(struct uart_port *port)

{

	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);

	unsigned long flags;



	free_irq(ltq_port->tx_irq, port);

	free_irq(ltq_port->rx_irq, port);

	free_irq(ltq_port->err_irq, port);



	spin_lock_irqsave(&ltq_port->lock, flags);

	__raw_writel(0, port->membase + LTQ_ASC_CON);

	asc_update_bits(ASCRXFCON_RXFEN, ASCRXFCON_RXFFLU,

		port->membase + LTQ_ASC_RXFCON);

	asc_update_bits(ASCTXFCON_TXFEN, ASCTXFCON_TXFFLU,

		port->membase + LTQ_ASC_TXFCON);

	spin_unlock_irqrestore(&ltq_port->lock, flags);

	if (!IS_ERR(ltq_port->clk))

		clk_disable_unprepare(ltq_port->clk);

}
@@ -390,6 +406,7 @@ lqasc_set_termios(struct uart_port *port, 
	unsigned int baud;

	unsigned int con = 0;

	unsigned long flags;

	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);



	cflag = new->c_cflag;

	iflag = new->c_iflag;
@@ -443,7 +460,7 @@ lqasc_set_termios(struct uart_port *port, 
	/* set error signals  - framing, parity  and overrun, enable receiver */

	con |= ASCCON_FEN | ASCCON_TOEN | ASCCON_ROEN;



	spin_lock_irqsave(&ltq_asc_lock, flags);

	spin_lock_irqsave(&ltq_port->lock, flags);



	/* set up CON */

	asc_update_bits(0, con, port->membase + LTQ_ASC_CON);
@@ -471,7 +488,7 @@ lqasc_set_termios(struct uart_port *port, 
	/* enable rx */

	__raw_writel(ASCWHBSTATE_SETREN, port->membase + LTQ_ASC_WHBSTATE);



	spin_unlock_irqrestore(&ltq_asc_lock, flags);

	spin_unlock_irqrestore(&ltq_port->lock, flags);



	/* Don't rewrite B0 */

	if (tty_termios_baud_rate(new))
@@ -589,17 +606,14 @@ lqasc_console_putchar(struct uart_port *port, int ch) 
static void lqasc_serial_port_write(struct uart_port *port, const char *s,

				    u_int count)

{

	unsigned long flags;



	spin_lock_irqsave(&ltq_asc_lock, flags);

	uart_console_write(port, s, count, lqasc_console_putchar);

	spin_unlock_irqrestore(&ltq_asc_lock, flags);

}



static void

lqasc_console_write(struct console *co, const char *s, u_int count)

{

	struct ltq_uart_port *ltq_port;

	unsigned long flags;



	if (co->index >= MAXPORTS)

		return;
@@ -608,7 +622,9 @@ lqasc_console_write(struct console *co, const char *s, u_int count) 
	if (!ltq_port)

		return;



	spin_lock_irqsave(&ltq_port->lock, flags);

	lqasc_serial_port_write(&ltq_port->port, s, count);

	spin_unlock_irqrestore(&ltq_port->lock, flags);

}



static int __init
@@ -766,6 +782,7 @@ lqasc_probe(struct platform_device *pdev) 
	ltq_port->rx_irq = irqres[1].start;

	ltq_port->err_irq = irqres[2].start;



	spin_lock_init(&ltq_port->lock);

	lqasc_port[line] = ltq_port;

	platform_set_drvdata(pdev, ltq_port);