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path: root/drivers/tty/serial/8250/8250_em.c
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Diffstat (limited to 'drivers/tty/serial/8250/8250_em.c')
-rw-r--r--drivers/tty/serial/8250/8250_em.c113
1 files changed, 90 insertions, 23 deletions
diff --git a/drivers/tty/serial/8250/8250_em.c b/drivers/tty/serial/8250/8250_em.c
index d94c3811a8f7..25a9ecf26be6 100644
--- a/drivers/tty/serial/8250/8250_em.c
+++ b/drivers/tty/serial/8250/8250_em.c
@@ -13,36 +13,49 @@
#include <linux/serial_reg.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
-#include <linux/slab.h>
#include "8250.h"
#define UART_DLL_EM 9
#define UART_DLM_EM 10
+#define UART_HCR0_EM 11
+
+/*
+ * A high value for UART_FCR_EM avoids overlapping with existing UART_*
+ * register defines. UART_FCR_EM_HW is the real HW register offset.
+ */
+#define UART_FCR_EM 0x10003
+#define UART_FCR_EM_HW 3
+
+#define UART_HCR0_EM_SW_RESET BIT(7) /* SW Reset */
struct serial8250_em_priv {
- struct clk *sclk;
int line;
};
-static void serial8250_em_serial_out(struct uart_port *p, int offset, int value)
+static void serial8250_em_serial_out_helper(struct uart_port *p, int offset,
+ int value)
{
switch (offset) {
case UART_TX: /* TX @ 0x00 */
writeb(value, p->membase);
break;
- case UART_FCR: /* FCR @ 0x0c (+1) */
case UART_LCR: /* LCR @ 0x10 (+1) */
case UART_MCR: /* MCR @ 0x14 (+1) */
case UART_SCR: /* SCR @ 0x20 (+1) */
writel(value, p->membase + ((offset + 1) << 2));
break;
+ case UART_FCR_EM:
+ writel(value, p->membase + (UART_FCR_EM_HW << 2));
+ break;
case UART_IER: /* IER @ 0x04 */
value &= 0x0f; /* only 4 valid bits - not Xscale */
fallthrough;
case UART_DLL_EM: /* DLL @ 0x24 (+9) */
case UART_DLM_EM: /* DLM @ 0x28 (+9) */
+ case UART_HCR0_EM: /* HCR0 @ 0x2c */
writel(value, p->membase + (offset << 2));
+ break;
}
}
@@ -51,20 +64,81 @@ static unsigned int serial8250_em_serial_in(struct uart_port *p, int offset)
switch (offset) {
case UART_RX: /* RX @ 0x00 */
return readb(p->membase);
+ case UART_LCR: /* LCR @ 0x10 (+1) */
case UART_MCR: /* MCR @ 0x14 (+1) */
case UART_LSR: /* LSR @ 0x18 (+1) */
case UART_MSR: /* MSR @ 0x1c (+1) */
case UART_SCR: /* SCR @ 0x20 (+1) */
return readl(p->membase + ((offset + 1) << 2));
+ case UART_FCR_EM:
+ return readl(p->membase + (UART_FCR_EM_HW << 2));
case UART_IER: /* IER @ 0x04 */
case UART_IIR: /* IIR @ 0x08 */
case UART_DLL_EM: /* DLL @ 0x24 (+9) */
case UART_DLM_EM: /* DLM @ 0x28 (+9) */
+ case UART_HCR0_EM: /* HCR0 @ 0x2c */
return readl(p->membase + (offset << 2));
}
return 0;
}
+static void serial8250_em_reg_update(struct uart_port *p, int off, int value)
+{
+ unsigned int ier, fcr, lcr, mcr, hcr0;
+
+ ier = serial8250_em_serial_in(p, UART_IER);
+ fcr = serial8250_em_serial_in(p, UART_FCR_EM);
+ lcr = serial8250_em_serial_in(p, UART_LCR);
+ mcr = serial8250_em_serial_in(p, UART_MCR);
+ hcr0 = serial8250_em_serial_in(p, UART_HCR0_EM);
+
+ serial8250_em_serial_out_helper(p, UART_FCR_EM, fcr |
+ UART_FCR_CLEAR_RCVR |
+ UART_FCR_CLEAR_XMIT);
+ serial8250_em_serial_out_helper(p, UART_HCR0_EM, hcr0 |
+ UART_HCR0_EM_SW_RESET);
+ serial8250_em_serial_out_helper(p, UART_HCR0_EM, hcr0 &
+ ~UART_HCR0_EM_SW_RESET);
+
+ switch (off) {
+ case UART_FCR_EM:
+ fcr = value;
+ break;
+ case UART_LCR:
+ lcr = value;
+ break;
+ case UART_MCR:
+ mcr = value;
+ break;
+ }
+
+ serial8250_em_serial_out_helper(p, UART_IER, ier);
+ serial8250_em_serial_out_helper(p, UART_FCR_EM, fcr);
+ serial8250_em_serial_out_helper(p, UART_MCR, mcr);
+ serial8250_em_serial_out_helper(p, UART_LCR, lcr);
+ serial8250_em_serial_out_helper(p, UART_HCR0_EM, hcr0);
+}
+
+static void serial8250_em_serial_out(struct uart_port *p, int offset, int value)
+{
+ switch (offset) {
+ case UART_TX:
+ case UART_SCR:
+ case UART_IER:
+ case UART_DLL_EM:
+ case UART_DLM_EM:
+ serial8250_em_serial_out_helper(p, offset, value);
+ break;
+ case UART_FCR:
+ serial8250_em_reg_update(p, UART_FCR_EM, value);
+ break;
+ case UART_LCR:
+ case UART_MCR:
+ serial8250_em_reg_update(p, offset, value);
+ break;
+ }
+}
+
static int serial8250_em_serial_dl_read(struct uart_8250_port *up)
{
return serial_in(up, UART_DLL_EM) | serial_in(up, UART_DLM_EM) << 8;
@@ -79,8 +153,10 @@ static void serial8250_em_serial_dl_write(struct uart_8250_port *up, int value)
static int serial8250_em_probe(struct platform_device *pdev)
{
struct serial8250_em_priv *priv;
+ struct device *dev = &pdev->dev;
struct uart_8250_port up;
struct resource *regs;
+ struct clk *sclk;
int irq, ret;
irq = platform_get_irq(pdev, 0);
@@ -88,31 +164,26 @@ static int serial8250_em_probe(struct platform_device *pdev)
return irq;
regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!regs) {
- dev_err(&pdev->dev, "missing registers\n");
- return -EINVAL;
- }
+ if (!regs)
+ return dev_err_probe(dev, -EINVAL, "missing registers\n");
- priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
- priv->sclk = devm_clk_get(&pdev->dev, "sclk");
- if (IS_ERR(priv->sclk)) {
- dev_err(&pdev->dev, "unable to get clock\n");
- return PTR_ERR(priv->sclk);
- }
+ sclk = devm_clk_get_enabled(dev, "sclk");
+ if (IS_ERR(sclk))
+ return dev_err_probe(dev, PTR_ERR(sclk), "unable to get clock\n");
memset(&up, 0, sizeof(up));
up.port.mapbase = regs->start;
up.port.irq = irq;
up.port.type = PORT_16750;
up.port.flags = UPF_FIXED_PORT | UPF_IOREMAP | UPF_FIXED_TYPE;
- up.port.dev = &pdev->dev;
+ up.port.dev = dev;
up.port.private_data = priv;
- clk_prepare_enable(priv->sclk);
- up.port.uartclk = clk_get_rate(priv->sclk);
+ up.port.uartclk = clk_get_rate(sclk);
up.port.iotype = UPIO_MEM32;
up.port.serial_in = serial8250_em_serial_in;
@@ -121,11 +192,8 @@ static int serial8250_em_probe(struct platform_device *pdev)
up.dl_write = serial8250_em_serial_dl_write;
ret = serial8250_register_8250_port(&up);
- if (ret < 0) {
- dev_err(&pdev->dev, "unable to register 8250 port\n");
- clk_disable_unprepare(priv->sclk);
- return ret;
- }
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "unable to register 8250 port\n");
priv->line = ret;
platform_set_drvdata(pdev, priv);
@@ -137,7 +205,6 @@ static int serial8250_em_remove(struct platform_device *pdev)
struct serial8250_em_priv *priv = platform_get_drvdata(pdev);
serial8250_unregister_port(priv->line);
- clk_disable_unprepare(priv->sclk);
return 0;
}
generated by cgit v1.2.3 (git 2.39.0) at 2024-09-14 02:41:21 +0300