[PATCH 1/3] serial: mpc52xx_uart: re-enable mpc5121 PSC UART support
Anatolij Gustschin
agust at denx.de
Tue Feb 2 18:47:42 EST 2010
Currently the support for MPC5121 PSC UART in the mpc52xx_uart
driver is broken (only console pre-initialized by the bootloader
works). Re-enable it now by providing MPC5121 specific ops
for PSCx clock activation, FIFO controller init/uninit and
MPC5121 PSC FIFO shared interrupt handling functions.
Signed-off-by: Anatolij Gustschin <agust at denx.de>
Cc: Grant Likely <grant.likely at secretlab.ca>
---
This patch has been tested using 5200/5121 multiplatform kernel
on tqm5200 and mpc5121ads boards (mpc52xx_uart staticaly linked
and as a driver module).
drivers/serial/mpc52xx_uart.c | 250 +++++++++++++++++++++++++++++++++++++++--
1 files changed, 239 insertions(+), 11 deletions(-)
diff --git a/drivers/serial/mpc52xx_uart.c b/drivers/serial/mpc52xx_uart.c
index 7ce9e9f..a084306 100644
--- a/drivers/serial/mpc52xx_uart.c
+++ b/drivers/serial/mpc52xx_uart.c
@@ -74,6 +74,7 @@
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_platform.h>
+#include <linux/clk.h>
#include <asm/mpc52xx.h>
#include <asm/mpc52xx_psc.h>
@@ -113,6 +114,7 @@ static void mpc52xx_uart_of_enumerate(void);
/* Forward declaration of the interruption handling routine */
static irqreturn_t mpc52xx_uart_int(int irq, void *dev_id);
+static irqreturn_t mpc5xxx_uart_process_int(struct uart_port *port);
/* Simple macro to test if a port is console or not. This one is taken
@@ -145,6 +147,11 @@ struct psc_ops {
void (*cw_disable_ints)(struct uart_port *port);
void (*cw_restore_ints)(struct uart_port *port);
unsigned long (*getuartclk)(void *p);
+ int (*clock)(struct uart_port *port, int enable);
+ int (*fifoc_init)(void);
+ void (*fifoc_uninit)(void);
+ void (*get_irq)(struct uart_port *, struct device_node *);
+ irqreturn_t (*handle_irq)(struct uart_port *port);
};
#ifdef CONFIG_PPC_MPC52xx
@@ -256,6 +263,18 @@ static unsigned long mpc52xx_getuartclk(void *p)
return mpc5xxx_get_bus_frequency(p) / 2;
}
+static void mpc52xx_psc_get_irq(struct uart_port *port, struct device_node *np)
+{
+ port->irqflags = IRQF_DISABLED;
+ port->irq = irq_of_parse_and_map(np, 0);
+}
+
+/* 52xx specific interrupt handler. The caller holds the port lock */
+static irqreturn_t mpc52xx_psc_handle_irq(struct uart_port *port)
+{
+ return mpc5xxx_uart_process_int(port);
+}
+
static struct psc_ops mpc52xx_psc_ops = {
.fifo_init = mpc52xx_psc_fifo_init,
.raw_rx_rdy = mpc52xx_psc_raw_rx_rdy,
@@ -273,14 +292,32 @@ static struct psc_ops mpc52xx_psc_ops = {
.cw_disable_ints = mpc52xx_psc_cw_disable_ints,
.cw_restore_ints = mpc52xx_psc_cw_restore_ints,
.getuartclk = mpc52xx_getuartclk,
+ .get_irq = mpc52xx_psc_get_irq,
+ .handle_irq = mpc52xx_psc_handle_irq,
};
#endif /* CONFIG_MPC52xx */
#ifdef CONFIG_PPC_MPC512x
#define FIFO_512x(port) ((struct mpc512x_psc_fifo __iomem *)(PSC(port)+1))
+
+/* PSC FIFO Controller for mpc512x */
+struct psc_fifoc {
+ u32 fifoc_cmd;
+ u32 fifoc_int;
+ u32 fifoc_dma;
+ u32 fifoc_axe;
+ u32 fifoc_debug;
+};
+
+static struct psc_fifoc __iomem *psc_fifoc;
+static unsigned int psc_fifoc_irq;
+
static void mpc512x_psc_fifo_init(struct uart_port *port)
{
+ /* /32 prescaler */
+ out_be16(&PSC(port)->mpc52xx_psc_clock_select, 0xdd00);
+
out_be32(&FIFO_512x(port)->txcmd, MPC512x_PSC_FIFO_RESET_SLICE);
out_be32(&FIFO_512x(port)->txcmd, MPC512x_PSC_FIFO_ENABLE_SLICE);
out_be32(&FIFO_512x(port)->txalarm, 1);
@@ -393,6 +430,161 @@ static unsigned long mpc512x_getuartclk(void *p)
return mpc5xxx_get_bus_frequency(p);
}
+#define DEFAULT_FIFO_SIZE 16
+
+static unsigned int __init get_fifo_size(struct device_node *np,
+ char *fifo_name)
+{
+ const unsigned int *fp;
+
+ fp = of_get_property(np, fifo_name, NULL);
+ if (fp)
+ return *fp;
+
+ pr_warning("no %s property in %s node, defaulting to %d\n",
+ fifo_name, np->full_name, DEFAULT_FIFO_SIZE);
+
+ return DEFAULT_FIFO_SIZE;
+}
+
+#define FIFOC(_base) ((struct mpc512x_psc_fifo __iomem *) \
+ ((u32)(_base) + sizeof(struct mpc52xx_psc)))
+
+/* Init PSC FIFO Controller */
+static int __init mpc512x_psc_fifoc_init(void)
+{
+ struct device_node *np;
+ void __iomem *psc;
+ unsigned int tx_fifo_size;
+ unsigned int rx_fifo_size;
+ int fifobase = 0; /* current fifo address in 32 bit words */
+
+ np = of_find_compatible_node(NULL, NULL,
+ "fsl,mpc5121-psc-fifo");
+ if (!np) {
+ pr_err("%s: Can't find FIFOC node\n", __func__);
+ return -ENODEV;
+ }
+
+ psc_fifoc = of_iomap(np, 0);
+ if (!psc_fifoc) {
+ pr_err("%s: Can't map FIFOC\n", __func__);
+ return -ENODEV;
+ }
+
+ psc_fifoc_irq = irq_of_parse_and_map(np, 0);
+ of_node_put(np);
+ if (psc_fifoc_irq == NO_IRQ) {
+ pr_err("%s: Can't get FIFOC irq\n", __func__);
+ iounmap(psc_fifoc);
+ return -ENODEV;
+ }
+
+ for_each_compatible_node(np, NULL, "fsl,mpc5121-psc-uart") {
+ tx_fifo_size = get_fifo_size(np, "fsl,tx-fifo-size");
+ rx_fifo_size = get_fifo_size(np, "fsl,rx-fifo-size");
+
+ /* size in register is in 4 byte units */
+ tx_fifo_size /= 4;
+ rx_fifo_size /= 4;
+ if (!tx_fifo_size)
+ tx_fifo_size = 1;
+ if (!rx_fifo_size)
+ rx_fifo_size = 1;
+
+ psc = of_iomap(np, 0);
+ if (!psc) {
+ pr_err("%s: Can't map %s device\n",
+ __func__, np->full_name);
+ continue;
+ }
+
+ /* FIFO space is 4KiB, check if requested size is available */
+ if ((fifobase + tx_fifo_size + rx_fifo_size) > 0x1000) {
+ pr_err("%s: no fifo space available for %s\n",
+ __func__, np->full_name);
+ iounmap(psc);
+ /*
+ * chances are that another device requests less
+ * fifo space, so we continue.
+ */
+ continue;
+ }
+ /* set tx and rx fifo size registers */
+ out_be32(&FIFOC(psc)->txsz, (fifobase << 16) | tx_fifo_size);
+ fifobase += tx_fifo_size;
+ out_be32(&FIFOC(psc)->rxsz, (fifobase << 16) | rx_fifo_size);
+ fifobase += rx_fifo_size;
+
+ /* reset and enable the slices */
+ out_be32(&FIFOC(psc)->txcmd, 0x80);
+ out_be32(&FIFOC(psc)->txcmd, 0x01);
+ out_be32(&FIFOC(psc)->rxcmd, 0x80);
+ out_be32(&FIFOC(psc)->rxcmd, 0x01);
+
+ iounmap(psc);
+ }
+
+ return 0;
+}
+
+static void __exit mpc512x_psc_fifoc_uninit(void)
+{
+ irq_dispose_mapping(psc_fifoc_irq);
+ iounmap(psc_fifoc);
+}
+
+/* 512x specific interrupt handler. The caller holds the port lock */
+static irqreturn_t mpc512x_psc_handle_irq(struct uart_port *port)
+{
+ unsigned long fifoc_int;
+ int psc_num;
+
+ /* Read pending PSC FIFOC interrupts */
+ fifoc_int = in_be32(&psc_fifoc->fifoc_int);
+
+ /* Check if it is an interrupt for this port */
+ psc_num = (port->mapbase & 0xf00) >> 8;
+ if (test_bit(psc_num, &fifoc_int) ||
+ test_bit(psc_num + 16, &fifoc_int))
+ return mpc5xxx_uart_process_int(port);
+
+ return IRQ_NONE;
+}
+
+static int mpc512x_psc_clock(struct uart_port *port, int enable)
+{
+ struct clk *psc_clk;
+ int psc_num;
+ char clk_name[10];
+
+ if (uart_console(port))
+ return 0;
+
+ psc_num = (port->mapbase & 0xf00) >> 8;
+ snprintf(clk_name, sizeof(clk_name), "psc%d_clk", psc_num);
+ psc_clk = clk_get(port->dev, clk_name);
+ if (IS_ERR(psc_clk)) {
+ dev_err(port->dev, "Failed to get PSC clock entry!\n");
+ return -ENODEV;
+ }
+
+ dev_dbg(port->dev, "%s %sable\n", clk_name, enable ? "en" : "dis");
+
+ if (enable)
+ clk_enable(psc_clk);
+ else
+ clk_disable(psc_clk);
+
+ return 0;
+}
+
+static void mpc512x_psc_get_irq(struct uart_port *port, struct device_node *np)
+{
+ port->irqflags = IRQF_SHARED;
+ port->irq = psc_fifoc_irq;
+}
+
static struct psc_ops mpc512x_psc_ops = {
.fifo_init = mpc512x_psc_fifo_init,
.raw_rx_rdy = mpc512x_psc_raw_rx_rdy,
@@ -410,6 +602,11 @@ static struct psc_ops mpc512x_psc_ops = {
.cw_disable_ints = mpc512x_psc_cw_disable_ints,
.cw_restore_ints = mpc512x_psc_cw_restore_ints,
.getuartclk = mpc512x_getuartclk,
+ .clock = mpc512x_psc_clock,
+ .fifoc_init = mpc512x_psc_fifoc_init,
+ .fifoc_uninit = mpc512x_psc_fifoc_uninit,
+ .get_irq = mpc512x_psc_get_irq,
+ .handle_irq = mpc512x_psc_handle_irq,
};
#endif
@@ -519,10 +716,15 @@ mpc52xx_uart_startup(struct uart_port *port)
struct mpc52xx_psc __iomem *psc = PSC(port);
int ret;
+ if (psc_ops->clock) {
+ ret = psc_ops->clock(port, 1);
+ if (ret)
+ return ret;
+ }
+
/* Request IRQ */
ret = request_irq(port->irq, mpc52xx_uart_int,
- IRQF_DISABLED | IRQF_SAMPLE_RANDOM,
- "mpc52xx_psc_uart", port);
+ port->irqflags, "mpc52xx_psc_uart", port);
if (ret)
return ret;
@@ -553,6 +755,9 @@ mpc52xx_uart_shutdown(struct uart_port *port)
port->read_status_mask = 0;
out_be16(&psc->mpc52xx_psc_imr, port->read_status_mask);
+ if (psc_ops->clock)
+ psc_ops->clock(port, 0);
+
/* Release interrupt */
free_irq(port->irq, port);
}
@@ -851,15 +1056,12 @@ mpc52xx_uart_int_tx_chars(struct uart_port *port)
}
static irqreturn_t
-mpc52xx_uart_int(int irq, void *dev_id)
+mpc5xxx_uart_process_int(struct uart_port *port)
{
- struct uart_port *port = dev_id;
unsigned long pass = ISR_PASS_LIMIT;
unsigned int keepgoing;
u8 status;
- spin_lock(&port->lock);
-
/* While we have stuff to do, we continue */
do {
/* If we don't find anything to do, we stop */
@@ -886,11 +1088,23 @@ mpc52xx_uart_int(int irq, void *dev_id)
} while (keepgoing);
- spin_unlock(&port->lock);
-
return IRQ_HANDLED;
}
+static irqreturn_t
+mpc52xx_uart_int(int irq, void *dev_id)
+{
+ struct uart_port *port = dev_id;
+ irqreturn_t ret;
+
+ spin_lock(&port->lock);
+
+ ret = psc_ops->handle_irq(port);
+
+ spin_unlock(&port->lock);
+
+ return ret;
+}
/* ======================================================================== */
/* Console ( if applicable ) */
@@ -1152,7 +1366,7 @@ mpc52xx_uart_of_probe(struct of_device *op, const struct of_device_id *match)
return -EINVAL;
}
- port->irq = irq_of_parse_and_map(op->node, 0);
+ psc_ops->get_irq(port, op->node);
if (port->irq == NO_IRQ) {
dev_dbg(&op->dev, "Could not get irq\n");
return -EINVAL;
@@ -1164,7 +1378,8 @@ mpc52xx_uart_of_probe(struct of_device *op, const struct of_device_id *match)
/* Add the port to the uart sub-system */
ret = uart_add_one_port(&mpc52xx_uart_driver, port);
if (ret) {
- irq_dispose_mapping(port->irq);
+ if (!(port->irqflags & IRQF_SHARED))
+ irq_dispose_mapping(port->irq);
return ret;
}
@@ -1180,7 +1395,8 @@ mpc52xx_uart_of_remove(struct of_device *op)
if (port) {
uart_remove_one_port(&mpc52xx_uart_driver, port);
- irq_dispose_mapping(port->irq);
+ if (!(port->irqflags & IRQF_SHARED))
+ irq_dispose_mapping(port->irq);
}
return 0;
@@ -1288,6 +1504,15 @@ mpc52xx_uart_init(void)
mpc52xx_uart_of_enumerate();
+ /*
+ * Map the PSC FIFO Controller and init if on MPC512x.
+ */
+ if (psc_ops->fifoc_init) {
+ ret = psc_ops->fifoc_init();
+ if (ret)
+ return ret;
+ }
+
ret = of_register_platform_driver(&mpc52xx_uart_of_driver);
if (ret) {
printk(KERN_ERR "%s: of_register_platform_driver failed (%i)\n",
@@ -1302,6 +1527,9 @@ mpc52xx_uart_init(void)
static void __exit
mpc52xx_uart_exit(void)
{
+ if (psc_ops->fifoc_uninit)
+ psc_ops->fifoc_uninit();
+
of_unregister_platform_driver(&mpc52xx_uart_of_driver);
uart_unregister_driver(&mpc52xx_uart_driver);
}
--
1.6.3.3
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