Adds missing functionality to e500plat machine which increases the
chance of given "real" firmware images to access SD cards.

Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Message-Id: <20221018210146.193159-8-shentey@gmail.com>
[PMD: Simplify using create_unimplemented_device("esdhc")]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 docs/system/ppc/ppce500.rst | 13 ++++++++++
 hw/ppc/Kconfig              |  2 ++
 hw/ppc/e500.c               | 48 ++++++++++++++++++++++++++++++++++++-
 hw/ppc/e500.h               |  1 +
 hw/ppc/e500plat.c           |  1 +
 5 files changed, 64 insertions(+), 1 deletion(-)

diff --git a/docs/system/ppc/ppce500.rst b/docs/system/ppc/ppce500.rst
index fa40e57d18..c9fe0915dc 100644
--- a/docs/system/ppc/ppce500.rst
+++ b/docs/system/ppc/ppce500.rst
@@ -19,6 +19,7 @@ The ``ppce500`` machine supports the following devices:
 * Power-off functionality via one GPIO pin
 * 1 Freescale MPC8xxx PCI host controller
 * VirtIO devices via PCI bus
+* 1 Freescale Enhanced Secure Digital Host controller (eSDHC)
 * 1 Freescale Enhanced Triple Speed Ethernet controller (eTSEC)
 
 Hardware configuration information
@@ -180,3 +181,15 @@ as follows:
       -kernel vmlinux \
       -drive if=pflash,file=/path/to/rootfs.ext2,format=raw \
       -append "rootwait root=/dev/mtdblock0"
+
+Alternatively, the root file system can also reside on an emulated SD card
+whose size must again be a power of two:
+
+.. code-block:: bash
+
+  $ qemu-system-ppc64 -M ppce500 -cpu e500mc -smp 4 -m 2G \
+      -display none -serial stdio \
+      -kernel vmlinux \
+      -device sd-card,drive=mydrive \
+      -drive id=mydrive,if=none,file=/path/to/rootfs.ext2,format=raw \
+      -append "rootwait root=/dev/mmcblk0"
diff --git a/hw/ppc/Kconfig b/hw/ppc/Kconfig
index b8d2522f45..72a311edcb 100644
--- a/hw/ppc/Kconfig
+++ b/hw/ppc/Kconfig
@@ -128,10 +128,12 @@ config E500
     select PFLASH_CFI01
     select PLATFORM_BUS
     select PPCE500_PCI
+    select SDHCI
     select SERIAL
     select MPC_I2C
     select FDT_PPC
     select DS1338
+    select UNIMP
 
 config E500PLAT
     bool
diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c
index 2fe496677c..2bef2f01cb 100644
--- a/hw/ppc/e500.c
+++ b/hw/ppc/e500.c
@@ -48,6 +48,8 @@
 #include "hw/net/fsl_etsec/etsec.h"
 #include "hw/i2c/i2c.h"
 #include "hw/irq.h"
+#include "hw/sd/sdhci.h"
+#include "hw/misc/unimp.h"
 
 #define EPAPR_MAGIC                (0x45504150)
 #define DTC_LOAD_PAD               0x1800000
@@ -66,11 +68,14 @@
 #define MPC8544_SERIAL1_REGS_OFFSET 0x4600ULL
 #define MPC8544_PCI_REGS_OFFSET    0x8000ULL
 #define MPC8544_PCI_REGS_SIZE      0x1000ULL
+#define MPC85XX_ESDHC_REGS_OFFSET  0x2e000ULL
+#define MPC85XX_ESDHC_REGS_SIZE    0x1000ULL
 #define MPC8544_UTIL_OFFSET        0xe0000ULL
 #define MPC8XXX_GPIO_OFFSET        0x000FF000ULL
 #define MPC8544_I2C_REGS_OFFSET    0x3000ULL
 #define MPC8XXX_GPIO_IRQ           47
 #define MPC8544_I2C_IRQ            43
+#define MPC85XX_ESDHC_IRQ          72
 #define RTC_REGS_OFFSET            0x68
 
 #define PLATFORM_CLK_FREQ_HZ       (400 * 1000 * 1000)
@@ -203,6 +208,22 @@ static void dt_i2c_create(void *fdt, const char *soc, const char *mpic,
     g_free(i2c);
 }
 
+static void dt_sdhc_create(void *fdt, const char *parent, const char *mpic)
+{
+    hwaddr mmio = MPC85XX_ESDHC_REGS_OFFSET;
+    hwaddr size = MPC85XX_ESDHC_REGS_SIZE;
+    int irq = MPC85XX_ESDHC_IRQ;
+    g_autofree char *name = NULL;
+
+    name = g_strdup_printf("%s/sdhc@%" PRIx64, parent, mmio);
+    qemu_fdt_add_subnode(fdt, name);
+    qemu_fdt_setprop(fdt, name, "sdhci,auto-cmd12", NULL, 0);
+    qemu_fdt_setprop_phandle(fdt, name, "interrupt-parent", mpic);
+    qemu_fdt_setprop_cells(fdt, name, "bus-width", 4);
+    qemu_fdt_setprop_cells(fdt, name, "interrupts", irq, 0x2);
+    qemu_fdt_setprop_cells(fdt, name, "reg", mmio, size);
+    qemu_fdt_setprop_string(fdt, name, "compatible", "fsl,esdhc");
+}
 
 typedef struct PlatformDevtreeData {
     void *fdt;
@@ -553,6 +574,10 @@ static int ppce500_load_device_tree(PPCE500MachineState *pms,
 
     dt_rtc_create(fdt, "i2c", "rtc");
 
+    /* sdhc */
+    if (pmc->has_esdhc) {
+        dt_sdhc_create(fdt, soc, mpic);
+    }
 
     gutil = g_strdup_printf("%s/global-utilities@%llx", soc,
                             MPC8544_UTIL_OFFSET);
@@ -982,7 +1007,8 @@ void ppce500_init(MachineState *machine)
                        0, qdev_get_gpio_in(mpicdev, 42), 399193,
                        serial_hd(1), DEVICE_BIG_ENDIAN);
     }
-        /* I2C */
+
+    /* I2C */
     dev = qdev_new("mpc-i2c");
     s = SYS_BUS_DEVICE(dev);
     sysbus_realize_and_unref(s, &error_fatal);
@@ -992,6 +1018,26 @@ void ppce500_init(MachineState *machine)
     i2c = (I2CBus *)qdev_get_child_bus(dev, "i2c");
     i2c_slave_create_simple(i2c, "ds1338", RTC_REGS_OFFSET);
 
+    /* eSDHC */
+    if (pmc->has_esdhc) {
+        create_unimplemented_device("esdhc",
+                                    pmc->ccsrbar_base + MPC85XX_ESDHC_REGS_OFFSET,
+                                    MPC85XX_ESDHC_REGS_SIZE);
+
+        /*
+         * Compatible with:
+         * - SD Host Controller Specification Version 2.0 Part A2
+         * (See MPC8569E Reference Manual)
+         */
+        dev = qdev_new(TYPE_SYSBUS_SDHCI);
+        qdev_prop_set_uint8(dev, "sd-spec-version", 2);
+        qdev_prop_set_uint8(dev, "endianness", DEVICE_BIG_ENDIAN);
+        s = SYS_BUS_DEVICE(dev);
+        sysbus_realize_and_unref(s, &error_fatal);
+        sysbus_connect_irq(s, 0, qdev_get_gpio_in(mpicdev, MPC85XX_ESDHC_IRQ));
+        memory_region_add_subregion(ccsr_addr_space, MPC85XX_ESDHC_REGS_OFFSET,
+                                    sysbus_mmio_get_region(s, 0));
+    }
 
     /* General Utility device */
     dev = qdev_new("mpc8544-guts");
diff --git a/hw/ppc/e500.h b/hw/ppc/e500.h
index 68f754ce50..8c09ef92e4 100644
--- a/hw/ppc/e500.h
+++ b/hw/ppc/e500.h
@@ -27,6 +27,7 @@ struct PPCE500MachineClass {
 
     int mpic_version;
     bool has_mpc8xxx_gpio;
+    bool has_esdhc;
     hwaddr platform_bus_base;
     hwaddr platform_bus_size;
     int platform_bus_first_irq;
diff --git a/hw/ppc/e500plat.c b/hw/ppc/e500plat.c
index 5bb1c603da..44bf874b0f 100644
--- a/hw/ppc/e500plat.c
+++ b/hw/ppc/e500plat.c
@@ -86,6 +86,7 @@ static void e500plat_machine_class_init(ObjectClass *oc, void *data)
     pmc->fixup_devtree = e500plat_fixup_devtree;
     pmc->mpic_version = OPENPIC_MODEL_FSL_MPIC_42;
     pmc->has_mpc8xxx_gpio = true;
+    pmc->has_esdhc = true;
     pmc->platform_bus_base = 0xf00000000ULL;
     pmc->platform_bus_size = 128 * MiB;
     pmc->platform_bus_first_irq = 5;
-- 
2.38.1

On 01/11/2022 23.29, Philippe Mathieu-Daudé wrote:
> Adds missing functionality to e500plat machine which increases the
> chance of given "real" firmware images to access SD cards.
> 
> Signed-off-by: Bernhard Beschow <shentey@gmail.com>
> Message-Id: <20221018210146.193159-8-shentey@gmail.com>
> [PMD: Simplify using create_unimplemented_device("esdhc")]
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---

  Hi!

I recently noticed that the QEMU advent calendar 2018 day 19 image 
(https://www.qemu-advent-calendar.org/2018/download/day19.tar.xz) is 
flooding the console with "mmc0: Internal clock never stabilised" messages 
when it's started like this:

  /qemu-system-ppc64 -vga none -nographic -monitor none -M ppce500 -cpu 
e5500  -kernel ../day19/uImage

This was not the case when I assembled the image in 2018. I bisected the 
problem and apparently this patch here is causing the problem. Do you know 
whether there is a way to fix this again?

  Thanks,
   Thomas

On Thu, 17 Apr 2025, Thomas Huth wrote:
> On 01/11/2022 23.29, Philippe Mathieu-Daudé wrote:
>> Adds missing functionality to e500plat machine which increases the
>> chance of given "real" firmware images to access SD cards.
>> 
>> Signed-off-by: Bernhard Beschow <shentey@gmail.com>
>> Message-Id: <20221018210146.193159-8-shentey@gmail.com>
>> [PMD: Simplify using create_unimplemented_device("esdhc")]
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>> ---
>
> Hi!
>
> I recently noticed that the QEMU advent calendar 2018 day 19 image 
> (https://www.qemu-advent-calendar.org/2018/download/day19.tar.xz) is flooding 
> the console with "mmc0: Internal clock never stabilised" messages when it's 
> started like this:
>
> /qemu-system-ppc64 -vga none -nographic -monitor none -M ppce500 -cpu e5500 
> -kernel ../day19/uImage
>
> This was not the case when I assembled the image in 2018. I bisected the 
> problem and apparently this patch here is causing the problem. Do you know 
> whether there is a way to fix this again?

That patch added the MMC/SD controller so no wonder it did not appear 
before. The error seems to be in Linux esdhci driver where it checks for:

sdhci_readl(host, ESDHC_PRSSTAT) & ESDHC_CLOCK_STABLE

So I think that bit should be set somewhere. Berhard had some patches for 
e500 so maybe there's already a fix for this somewhere.

Regards,
BALATON Zoltan

Am 17. April 2025 21:40:44 UTC schrieb BALATON Zoltan <balaton@eik.bme.hu>:
>On Thu, 17 Apr 2025, Thomas Huth wrote:
>> On 01/11/2022 23.29, Philippe Mathieu-Daudé wrote:
>>> Adds missing functionality to e500plat machine which increases the
>>> chance of given "real" firmware images to access SD cards.
>>> 
>>> Signed-off-by: Bernhard Beschow <shentey@gmail.com>
>>> Message-Id: <20221018210146.193159-8-shentey@gmail.com>
>>> [PMD: Simplify using create_unimplemented_device("esdhc")]
>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>>> ---
>> 
>> Hi!
>> 
>> I recently noticed that the QEMU advent calendar 2018 day 19 image (https://www.qemu-advent-calendar.org/2018/download/day19.tar.xz) is flooding the console with "mmc0: Internal clock never stabilised" messages when it's started like this:
>> 
>> /qemu-system-ppc64 -vga none -nographic -monitor none -M ppce500 -cpu e5500 -kernel ../day19/uImage
>> 
>> This was not the case when I assembled the image in 2018. I bisected the problem and apparently this patch here is causing the problem. Do you know whether there is a way to fix this again?
>
>That patch added the MMC/SD controller so no wonder it did not appear before. The error seems to be in Linux esdhci driver where it checks for:
>
>sdhci_readl(host, ESDHC_PRSSTAT) & ESDHC_CLOCK_STABLE
>
>So I think that bit should be set somewhere. Berhard had some patches for e500 so maybe there's already a fix for this somewhere.

This logic is already implemented in the USDHC device model. Given that the e500 and the i.mx machines need the same modifications to make u-boot work, and given that the imx25 machine also uses the USDHC model even though the original has an ESDHC, the USDHC might be a better fit here. AFAICS only the interrupt bits specific to the ESDHC need special treatment here -- which could be achieved e.g. by subclassing.

I could send a patch for that. Volunteers ahead for a timely solution.

Best regards,
Bernhard

>
>Regards,
>BALATON Zoltan