Re: [PATCH] m68k: coldfire: Support resources for UART
From: Jean-Michel Hautbois
Date: Thu Dec 05 2024 - 08:07:01 EST
Hi Greg,
On 05/12/2024 14:01, Greg Ungerer wrote:
Hi JM,
On 4/12/24 21:32, Jean-Michel Hautbois wrote:
On 04/12/2024 12:15, Greg Ungerer wrote:
On 4/12/24 20:58, Jean-Michel Hautbois wrote:
On 04/12/2024 11:54, Greg Ungerer wrote:
On 2/12/24 20:34, Jean-Michel Hautbois wrote:
In order to use the eDMA channels for UART, the mcf_platform_uart
needs
to be changed. Instead of adding another custom member for the
structure, use a resource tree in a platform_device per UART. It then
makes it possible to have a device named like "mcfuart.N" with N the
UART number.
Later, adding the dma channel in the mcf tty driver will also be more
straightfoward.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@xxxxxxxxxx>
---
arch/m68k/coldfire/device.c | 96 +++++++++++++
+-------------------------------
drivers/tty/serial/mcf.c | 69 +++++++++++++++++++-------------
2 files changed, 70 insertions(+), 95 deletions(-)
diff --git a/arch/m68k/coldfire/device.c b/arch/m68k/coldfire/
device.c
index
b6958ec2a220cf91a78a14fc7fa18749451412f7..fd7d0b0ce7eb2970cb8ffe33589fe8d7e88c268d 100644
--- a/arch/m68k/coldfire/device.c
+++ b/arch/m68k/coldfire/device.c
@@ -24,73 +24,35 @@
#include <linux/platform_data/dma-mcf-edma.h>
#include <linux/platform_data/mmc-esdhc-mcf.h>
-/*
- * All current ColdFire parts contain from 2, 3, 4 or 10 UARTS.
- */
-static struct mcf_platform_uart mcf_uart_platform_data[] = {
- {
- .mapbase = MCFUART_BASE0,
- .irq = MCF_IRQ_UART0,
- },
- {
- .mapbase = MCFUART_BASE1,
- .irq = MCF_IRQ_UART1,
- },
-#ifdef MCFUART_BASE2
- {
- .mapbase = MCFUART_BASE2,
- .irq = MCF_IRQ_UART2,
- },
-#endif
-#ifdef MCFUART_BASE3
- {
- .mapbase = MCFUART_BASE3,
- .irq = MCF_IRQ_UART3,
- },
-#endif
-#ifdef MCFUART_BASE4
- {
- .mapbase = MCFUART_BASE4,
- .irq = MCF_IRQ_UART4,
- },
-#endif
-#ifdef MCFUART_BASE5
- {
- .mapbase = MCFUART_BASE5,
- .irq = MCF_IRQ_UART5,
- },
-#endif
-#ifdef MCFUART_BASE6
- {
- .mapbase = MCFUART_BASE6,
- .irq = MCF_IRQ_UART6,
- },
-#endif
-#ifdef MCFUART_BASE7
- {
- .mapbase = MCFUART_BASE7,
- .irq = MCF_IRQ_UART7,
+static u64 mcf_uart_mask = DMA_BIT_MASK(32);
+
+static struct resource mcf_uart0_resource[] = {
+ [0] = {
+ .start = MCFUART_BASE0,
+ .end = MCFUART_BASE0 + 0x3fff,
+ .flags = IORESOURCE_MEM,
},
-#endif
-#ifdef MCFUART_BASE8
- {
- .mapbase = MCFUART_BASE8,
- .irq = MCF_IRQ_UART8,
+ [1] = {
+ .start = 2,
+ .end = 3,
+ .flags = IORESOURCE_DMA,
},
-#endif
-#ifdef MCFUART_BASE9
- {
- .mapbase = MCFUART_BASE9,
- .irq = MCF_IRQ_UART9,
+ [2] = {
+ .start = MCF_IRQ_UART0,
+ .end = MCF_IRQ_UART0,
+ .flags = IORESOURCE_IRQ,
},
-#endif
- { },
};
-static struct platform_device mcf_uart = {
+static struct platform_device mcf_uart0 = {
.name = "mcfuart",
.id = 0,
- .dev.platform_data = mcf_uart_platform_data,
+ .num_resources = ARRAY_SIZE(mcf_uart0_resource),
+ .resource = mcf_uart0_resource,
+ .dev = {
+ .dma_mask = &mcf_uart_mask,
+ .coherent_dma_mask = DMA_BIT_MASK(32),
+ },
};
#ifdef MCFFEC_BASE0
@@ -485,12 +447,12 @@ static struct platform_device mcf_i2c5 = {
static const struct dma_slave_map mcf_edma_map[] = {
{ "dreq0", "rx-tx", MCF_EDMA_FILTER_PARAM(0) },
{ "dreq1", "rx-tx", MCF_EDMA_FILTER_PARAM(1) },
- { "uart.0", "rx", MCF_EDMA_FILTER_PARAM(2) },
- { "uart.0", "tx", MCF_EDMA_FILTER_PARAM(3) },
- { "uart.1", "rx", MCF_EDMA_FILTER_PARAM(4) },
- { "uart.1", "tx", MCF_EDMA_FILTER_PARAM(5) },
- { "uart.2", "rx", MCF_EDMA_FILTER_PARAM(6) },
- { "uart.2", "tx", MCF_EDMA_FILTER_PARAM(7) },
+ { "mcfuart.0", "rx", MCF_EDMA_FILTER_PARAM(2) },
+ { "mcfuart.0", "tx", MCF_EDMA_FILTER_PARAM(3) },
+ { "mcfuart.1", "rx", MCF_EDMA_FILTER_PARAM(4) },
+ { "mcfuart.1", "tx", MCF_EDMA_FILTER_PARAM(5) },
+ { "mcfuart.2", "rx", MCF_EDMA_FILTER_PARAM(6) },
+ { "mcfuart.2", "tx", MCF_EDMA_FILTER_PARAM(7) },
{ "timer0", "rx-tx", MCF_EDMA_FILTER_PARAM(8) },
{ "timer1", "rx-tx", MCF_EDMA_FILTER_PARAM(9) },
{ "timer2", "rx-tx", MCF_EDMA_FILTER_PARAM(10) },
@@ -623,7 +585,7 @@ static struct platform_device mcf_flexcan0 = {
#endif /* MCFFLEXCAN_SIZE */
static struct platform_device *mcf_devices[] __initdata = {
- &mcf_uart,
+ &mcf_uart0,
#ifdef MCFFEC_BASE0
&mcf_fec0,
#endif
diff --git a/drivers/tty/serial/mcf.c b/drivers/tty/serial/mcf.c
index
93e7dda4d39acd23daf8c0d4c29ac8d666f263c5..07b8decfdb6005f0265dd130765e45c3fd1715eb 100644
--- a/drivers/tty/serial/mcf.c
+++ b/drivers/tty/serial/mcf.c
@@ -570,31 +570,46 @@ static struct uart_driver mcf_driver = {
static int mcf_probe(struct platform_device *pdev)
{
- struct mcf_platform_uart *platp = dev_get_platdata(&pdev->dev);
struct uart_port *port;
- int i;
-
- for (i = 0; ((i < MCF_MAXPORTS) && (platp[i].mapbase)); i++) {
- port = &mcf_ports[i].port;
-
- port->line = i;
- port->type = PORT_MCF;
- port->mapbase = platp[i].mapbase;
- port->membase = (platp[i].membase) ? platp[i].membase :
- (unsigned char __iomem *) platp[i].mapbase;
- port->dev = &pdev->dev;
- port->iotype = SERIAL_IO_MEM;
- port->irq = platp[i].irq;
- port->uartclk = MCF_BUSCLK;
- port->ops = &mcf_uart_ops;
- port->flags = UPF_BOOT_AUTOCONF;
- port->rs485_config = mcf_config_rs485;
- port->rs485_supported = mcf_rs485_supported;
- port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MCF_CONSOLE);
-
- uart_add_one_port(&mcf_driver, port);
+ struct mcf_uart *pp;
+ struct resource *res;
+ void __iomem *base;
+ int id = pdev->id;
+
+ if (id == -1 || id >= MCF_MAXPORTS) {
+ dev_err(&pdev->dev, "uart%d out of range\n",
+ id);
+ return -EINVAL;
}
+ port = &mcf_ports[id].port;
+ port->line = id;
+
+ base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ port->mapbase = res->start;
+ port->membase = base;
+
+ port->irq = platform_get_irq(pdev, 0);
+ if (port->irq < 0)
+ return port->irq;
+
+ port->type = PORT_MCF;
+ port->dev = &pdev->dev;
+ port->iotype = SERIAL_IO_MEM;
+ port->uartclk = MCF_BUSCLK;
+ port->ops = &mcf_uart_ops;
+ port->flags = UPF_BOOT_AUTOCONF;
+ port->rs485_config = mcf_config_rs485;
+ port->rs485_supported = mcf_rs485_supported;
+ port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MCF_CONSOLE);
+
+ pp = container_of(port, struct mcf_uart, port);
+
+ uart_add_one_port(&mcf_driver, port);
+
This breaks platforms with more than one UART - which is quite a
few of
the ColdFire platforms. Numerous boards bring and use more than one
UART.
I don't get why, as I have two uarts here, and each is detected
properly when declaring those in my platform ? I get that it breaks
existing detection (we are parsing all uarts even when only one or
two is used) but it does not prevent it to work ?
Building and testing on an M5208EVB platform.
With original un-modified code boot console shows:
...
[ 0.110000] romfs: ROMFS MTD (C) 2007 Red Hat, Inc.
[ 0.110000] ColdFire internal UART serial driver
[ 0.110000] mcfuart.0: ttyS0 at MMIO 0xfc060000 (irq = 90,
base_baud = 5208333) is a ColdFire UART
[ 0.120000] printk: legacy console [ttyS0] enabled
[ 0.120000] mcfuart.0: ttyS1 at MMIO 0xfc064000 (irq = 91,
base_baud = 5208333) is a ColdFire UART
[ 0.120000] mcfuart.0: ttyS2 at MMIO 0xfc068000 (irq = 92,
base_baud = 5208333) is a ColdFire UART
[ 0.130000] brd: module loaded
...
But with this change applied only the first port is probed:
...
[ 0.120000] romfs: ROMFS MTD (C) 2007 Red Hat, Inc.
[ 0.120000] ColdFire internal UART serial driver
[ 0.130000] mcfuart.0: ttyS0 at MMIO 0xfc060000 (irq = 90,
base_baud = 5208333) is a ColdFire UART
[ 0.130000] printk: legacy console [ttyS0] enabled
[ 0.130000] brd: module loaded
...
OK, I see what you mean. Let me try to explain why I did it :-).
The idea is to avoid probing a UART device which may exist as such on
the core, but not be used as UART at all (on my board, for instance, I
have uart2 and uart6, I don't need any other UART to be probed).
So, based on what I think is the dts philosophy, you declare the
devices you really need to probe ?
You can do this too, with the old style platform setups.
What you want is to have a separate board file just for your board.
There is a few examples already in arch/m68k/coldfire/ like amcore.c,
firebee.c, nettel.c and stmark2.c. None currently specifically extract
out UARTS - no one really seemed to have a need for that in the past.
Most ColdFire parts have 2 or 3 UARTS, the 5441x family is an out-lier
here with 10.
Anyway, the device.c entries are really just a catch-all for the most
common devices and their most commonly used configurations.
Thanks for answering !
I know I can have a dedicated file for my board (which i have tbh) but
device.c is always built when you select CONFIG_COLDFIRE so, I would end
up with 10 UARTs probed anyways ?
Is there no way for this patch to find a path ? I mean, I can keep the
existing behavior, and have everything probed in device.c if the BASE
address is declared. But I don't want my board to have all 10 UARTs and
I don't want to locally patch the Makefile to remove the device.c from
the built-in ?
Thanks,
JM
Regards
Greg
I can add all the uarts as resources with the ifdefs like before, but
on the M54418 it will always probe 10 devices, which sounds like a bit
overkill ?
Thanks !
JM
Regards
Greg
static struct resource mcf_uart2_resource[] = {
[0] = {
.start = MCFUART_BASE2,
.end = MCFUART_BASE2 + 0x3fff,
.flags = IORESOURCE_MEM,
},
[1] = {
.start = 6,
.end = 7,
.flags = IORESOURCE_DMA,
},
[2] = {
.start = MCF_IRQ_UART2,
.end = MCF_IRQ_UART2,
.flags = IORESOURCE_IRQ,
},
};
static struct platform_device mcf_uart2 = {
.name = "mcfuart",
.id = 2,
.num_resources = ARRAY_SIZE(mcf_uart2_resource),
.resource = mcf_uart2_resource,
.dev = {
.dma_mask = &mcf_uart_mask,
.coherent_dma_mask = DMA_BIT_MASK(32),
},
};
static struct resource mcf_uart6_resource[] = {
[0] = {
.start = MCFUART_BASE6,
.end = MCFUART_BASE6 + 0x3fff,
.flags = IORESOURCE_MEM,
},
[1] = {
.start = 22,
.end = 23,
.flags = IORESOURCE_DMA,
},
[2] = {
.start = MCF_IRQ_UART6,
.end = MCF_IRQ_UART6,
.flags = IORESOURCE_IRQ,
},
};
static struct platform_device mcf_uart6 = {
.name = "mcfuart",
.id = 6,
.num_resources = ARRAY_SIZE(mcf_uart6_resource),
.resource = mcf_uart6_resource,
.dev = {
.dma_mask = &mcf_uart_mask,
.coherent_dma_mask = DMA_BIT_MASK(32),
},
};
JM
Regards
Greg
return 0;
}
@@ -603,13 +618,11 @@ static int mcf_probe(struct platform_device
*pdev)
static void mcf_remove(struct platform_device *pdev)
{
struct uart_port *port;
- int i;
+ int id = pdev->id;
- for (i = 0; (i < MCF_MAXPORTS); i++) {
- port = &mcf_ports[i].port;
- if (port)
- uart_remove_one_port(&mcf_driver, port);
- }
+ port = &mcf_ports[id].port;
+ if (port)
+ uart_remove_one_port(&mcf_driver, port);
}
/
****************************************************************************/
---
base-commit: e457f18d7f25288d143c1fe024a620d0b15caec1
change-id: 20241202-m5441x_uart_resource-729b30c15363
Best regards,