[Skiboot] [RFC PATCH] plat/qemu: Add BT device

[Benjamin Herrenschmidt]

On Thu, 2015-11-12 at 18:23 +0100, Cédric Le Goater wrote:
> This adds the BT device used to communicate with the BMC. This is
> sufficient to handle IPMI messaging, power_downs and reboots the
> way openpower systems do it.
> 
> This patch needs to run on Ben's tree adding the support for the
> PowerNV platform in qemu, plus some patches of mine. You will find
> the resulting tree here :
> 
> 	https://github.com/legoater/qemu/tree/powernv
> 
> It's basic, probably a little too hacky, but it does provide enough
> of a framework to handle communication with the BMC. Is it something
> we want to add to qemu ? 

Thanks !

There's actually a pretty complete IPMI stack with BT etc... being
written by Corey Minyard. He submitted it a while back, it didn't go in
but he told me he plans to resubmit reasonably soon:

https://lists.gnu.org/archive/html/qemu-devel/2015-04/msg00641.html

Cheers,
Ben.

> Comments welcome.
> 
> Thanks,
> 
> C.
> 
> 
> Signed-off-by: Cédric Le Goater <clg at fr.ibm.com>
> ---
>  hw/bt.c               |    8 +++++++
>  platforms/qemu/qemu.c |   53
> ++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 61 insertions(+)
> 
> Index: skiboot.git/platforms/qemu/qemu.c
> ===================================================================
> --- skiboot.git.orig/platforms/qemu/qemu.c
> +++ skiboot.git/platforms/qemu/qemu.c
> @@ -21,6 +21,13 @@
>  #include <console.h>
>  #include <opal.h>
>  #include <psi.h>
> +#include <bt.h>
> +#include <ipmi.h>
> +
> +/* BT config */
> +#define BT_IO_BASE	0xe4
> +#define BT_IO_COUNT	3
> +#define BT_LPC_IRQ	10
>  
>  static void qemu_init(void)
>  {
> @@ -32,6 +39,33 @@ static void qemu_init(void)
>  	 * chiptod_init()
>  	 */
>  	lpc_rtc_init();
> +	bt_init();
> +}
> +
> +static void qemu_dt_fixup_bt(struct dt_node *lpc)
> +{
> +	struct dt_node *bt;
> +	char namebuf[32];
> +
> +	/* First check if the BT interface is already there */
> +	dt_for_each_child(lpc, bt) {
> +		if (dt_node_is_compatible(bt, "bt"))
> +			return;
> +	}
> +
> +	snprintf(namebuf, sizeof(namebuf), "ipmi-bt at i%x",
> BT_IO_BASE);
> +	bt = dt_new(lpc, namebuf);
> +
> +	dt_add_property_cells(bt, "reg",
> +			      1, /* IO space */
> +			      BT_IO_BASE, BT_IO_COUNT);
> +	dt_add_property_strings(bt, "compatible", "ipmi-bt");
> +
> +	/* Mark it as reserved to avoid Linux trying to claim it */
> +	dt_add_property_strings(bt, "status", "reserved");
> +
> +	dt_add_property_cells(bt, "interrupts", BT_LPC_IRQ);
> +	dt_add_property_cells(bt, "interrupt-parent", lpc->phandle);
>  }
>  
>  static void qemu_dt_fixup_uart(struct dt_node *lpc)
> @@ -113,6 +147,7 @@ static void qemu_dt_fixup(void)
>  
>  	qemu_dt_fixup_rtc(primary_lpc);
>  	qemu_dt_fixup_uart(primary_lpc);
> +	qemu_dt_fixup_bt(primary_lpc);
>  }
>  
>  static void qemu_ext_irq_serirq_cpld(unsigned int chip_id)
> @@ -120,6 +155,21 @@ static void qemu_ext_irq_serirq_cpld(uns
>  	lpc_all_interrupts(chip_id);
>  }
>  
> +static int64_t qemu_ipmi_power_down(uint64_t request)
> +{
> +	if (request != IPMI_CHASSIS_PWR_DOWN) {
> +		prlog(PR_WARNING, "PLAT: unexpected shutdown request
> %llx\n",
> +				   request);
> +	}
> +
> +	return ipmi_chassis_control(request);
> +}
> +
> +static int64_t qemu_ipmi_reboot(void)
> +{
> +	return ipmi_chassis_control(IPMI_CHASSIS_HARD_RESET);
> +}
> +
>  static bool qemu_probe(void)
>  {
>  	if (!dt_node_is_compatible(dt_root, "qemu,powernv"))
> @@ -145,4 +195,7 @@ DECLARE_PLATFORM(qemu) = {
>  	.probe		= qemu_probe,
>  	.init		= qemu_init,
>  	.external_irq   = qemu_ext_irq_serirq_cpld,
> +	.cec_power_down = qemu_ipmi_power_down,
> +	.cec_reboot     = qemu_ipmi_reboot,
> +	.terminate	= ipmi_terminate,
>  };