PPC: E500 [PATCH v2 ]: Add FSL i2c controller and integrate RTC with it.

Changes since v1:
    * Move it to GPL v2+ 
    * Replace the printf with DPRINTF
    * Fix the coding style issues
    * Change the subject line

This patch adds an emulation model for i2c controller found on most of the FSL SoCs.
It also integrates the RTC that sits on the i2c Bus with e500 machine model.



Signed-off-by: Amit Singh Tomar <amit.tomar@freescale.com>
---
 default-configs/ppc-softmmu.mak   |    2 +
 default-configs/ppc64-softmmu.mak |    2 +
 hw/i2c/Makefile.objs              |    1 +
 hw/i2c/mpc_i2c.c                  |  364 +++++++++++++++++++++++++++++++++++++
 hw/ppc/e500.c                     |   50 ++++-
 5 files changed, 418 insertions(+), 1 deletion(-)
 create mode 100644 hw/i2c/mpc_i2c.c

On 29.12.14 11:25, Amit Tomar wrote:
> 
> Changes since v1:
>     * Move it to GPL v2+ 
>     * Replace the printf with DPRINTF
>     * Fix the coding style issues
>     * Change the subject line
> 
> This patch adds an emulation model for i2c controller found on most of the FSL SoCs.
> It also integrates the RTC that sits on the i2c Bus with e500 machine model.
> 
> 
> 
> Signed-off-by: Amit Singh Tomar <amit.tomar@freescale.com>
> ---
>  default-configs/ppc-softmmu.mak   |    2 +
>  default-configs/ppc64-softmmu.mak |    2 +
>  hw/i2c/Makefile.objs              |    1 +
>  hw/i2c/mpc_i2c.c                  |  364 +++++++++++++++++++++++++++++++++++++
>  hw/ppc/e500.c                     |   50 ++++-
>  5 files changed, 418 insertions(+), 1 deletion(-)
>  create mode 100644 hw/i2c/mpc_i2c.c
> 
> diff --git a/default-configs/ppc-softmmu.mak b/default-configs/ppc-softmmu.mak
> index d725b23..6fdd39a 100644
> --- a/default-configs/ppc-softmmu.mak
> +++ b/default-configs/ppc-softmmu.mak
> @@ -9,6 +9,8 @@ CONFIG_M48T59=y
>  CONFIG_VGA=y
>  CONFIG_VGA_PCI=y
>  CONFIG_SERIAL=y
> +CONFIG_MPC_I2C=y
> +CONFIG_DS1338=y
>  CONFIG_PARALLEL=y
>  CONFIG_I8254=y
>  CONFIG_PCKBD=y
> diff --git a/default-configs/ppc64-softmmu.mak b/default-configs/ppc64-softmmu.mak
> index bd30d69..3ad3f58 100644
> --- a/default-configs/ppc64-softmmu.mak
> +++ b/default-configs/ppc64-softmmu.mak
> @@ -9,6 +9,8 @@ CONFIG_M48T59=y
>  CONFIG_VGA=y
>  CONFIG_VGA_PCI=y
>  CONFIG_SERIAL=y
> +CONFIG_MPC_I2C=y
> +CONFIG_DS1338=y
>  CONFIG_PARALLEL=y
>  CONFIG_I8254=y
>  CONFIG_PCKBD=y
> diff --git a/hw/i2c/Makefile.objs b/hw/i2c/Makefile.objs
> index 648278e..6e6d00d 100644
> --- a/hw/i2c/Makefile.objs
> +++ b/hw/i2c/Makefile.objs
> @@ -4,4 +4,5 @@ common-obj-$(CONFIG_ACPI) += smbus_ich9.o
>  common-obj-$(CONFIG_APM) += pm_smbus.o
>  common-obj-$(CONFIG_BITBANG_I2C) += bitbang_i2c.o
>  common-obj-$(CONFIG_EXYNOS4) += exynos4210_i2c.o
> +common-obj-$(CONFIG_MPC_I2C) += mpc_i2c.o
>  obj-$(CONFIG_OMAP) += omap_i2c.o
> diff --git a/hw/i2c/mpc_i2c.c b/hw/i2c/mpc_i2c.c
> new file mode 100644
> index 0000000..84d13dd
> --- /dev/null
> +++ b/hw/i2c/mpc_i2c.c
> @@ -0,0 +1,364 @@
> +/*
> + * Copyright (C) 2014 Freescale Semiconductor, Inc. All rights reserved.
> + *
> + * Author: Amit Tomar, <amit.tomar@freescale.com>
> + *
> + * Description:
> + * This file is derived from IMX I2C controller,
> + * by Jean-Christophe DUBOIS .
> + *
> + * Thanks to Scott Wood and Alexander Graf for their kind help on this.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License, version 2 or later,
> + * as published by the Free Software Foundation.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library; if not, see <http://www.gnu.org/licenses/>.
> +*/
> +
> +#include "hw/sysbus.h"
> +#include "hw/i2c/i2c.h"
> +#include "qemu/bitops.h"
> +#include "hw/ptimer.h"
> +
> +/*#define DEBUG_I2C*/
> +
> +#ifdef DEBUG_I2C
> +#define DPRINTF(fmt, ...)              \
> +    do { fprintf(stderr, "mpc_i2c[%s]: " fmt, __func__, ## __VA_ARGS__); \
> +    } while (0)
> +#else
> +#define DPRINTF(fmt, ...) do {} while (0)
> +#endif
> +
> +#define TYPE_MPC_I2C "mpc-i2c"
> +#define MPC_I2C(obj) \
> +    OBJECT_CHECK(MPCI2CState, (obj), TYPE_MPC_I2C)
> +
> +#define MPC_I2C_ADR   0x00
> +#define MPC_I2C_FDR   0x04
> +#define MPC_I2C_CR    0x08
> +#define MPC_I2C_SR    0x0c
> +#define MPC_I2C_DR    0x10
> +#define MPC_I2C_DFSRR 0x14
> +
> +#define CCR_MEN  (1<<7)
> +#define CCR_MIEN (1<<6)
> +#define CCR_MSTA (1<<5)
> +#define CCR_MTX  (1<<4)
> +#define CCR_TXAK (1<<3)
> +#define CCR_RSTA (1<<2)
> +#define CCR_BCST (1<<0)
> +
> +#define CSR_MCF  (1<<7)
> +#define CSR_MAAS (1<<6)
> +#define CSR_MBB  (1<<5)
> +#define CSR_MAL  (1<<4)
> +#define CSR_SRW  (1<<2)
> +#define CSR_MIF  (1<<1)
> +#define CSR_RXAK (1<<0)
> +
> +#define CADR_MASK 0xFE
> +#define CFDR_MASK 0x3F
> +#define CCR_MASK  0xFC
> +#define CSR_MASK  0xED
> +#define CDR_MASK  0xFF
> +
> +#define CYCLE_RESET 0xFF
> +
> +typedef struct MPCI2CState {
> +    SysBusDevice parent_obj;
> +
> +    I2CBus *bus;
> +    qemu_irq irq;
> +    MemoryRegion iomem;
> +
> +    uint8_t address;
> +    uint8_t adr;
> +    uint8_t fdr;
> +    uint8_t cr;
> +    uint8_t sr;
> +    uint8_t dr;
> +    uint8_t dfssr;
> +} MPCI2CState;
> +
> +static bool mpc_i2c_is_enabled(MPCI2CState *s)
> +{
> +    return s->cr & CCR_MEN;
> +}
> +
> +static bool mpc_i2c_is_master(MPCI2CState *s)
> +{
> +    return s->cr & CCR_MSTA;
> +}
> +
> +static bool mpc_i2c_direction_is_tx(MPCI2CState *s)
> +{
> +    return s->cr & CCR_MTX;
> +}
> +
> +static bool mpc_i2c_irq_pending(MPCI2CState *s)
> +{
> +    return s->sr & CSR_MIF;
> +}
> +
> +static bool mpc_i2c_irq_is_enabled(MPCI2CState *s)
> +{
> +    return s->cr & CCR_MIEN;
> +}
> +
> +static void mpc_i2c_reset(DeviceState *dev)
> +{
> +    MPCI2CState *i2c = MPC_I2C(dev);
> +
> +    i2c->address = 0xFF;
> +    i2c->adr = 0x00;
> +    i2c->fdr = 0x00;
> +    i2c->cr =  0x00;
> +    i2c->sr =  0x81;
> +    i2c->dr =  0x00;
> +}
> +
> +static void mpc_i2c_irq(MPCI2CState *s)
> +{
> +    bool irq_active = false;
> +
> +    if (mpc_i2c_is_enabled(s) && mpc_i2c_irq_is_enabled(s)
> +                              && mpc_i2c_irq_pending(s)) {
> +        irq_active = true;
> +    }
> +
> +    if (irq_active) {
> +        qemu_irq_raise(s->irq);
> +    } else {
> +        qemu_irq_lower(s->irq);
> +    }
> +}
> +
> +static void mpc_i2c_soft_reset(MPCI2CState *s)
> +{
> +    /* This is a soft reset. ADR is preserved during soft resets */
> +    uint8_t adr = s->adr;
> +    mpc_i2c_reset(DEVICE(s));
> +    s->adr = adr;
> +}
> +
> +static void  mpc_i2c_address_send(MPCI2CState *s)
> +{
> +    /* if returns non zero slave address is not right */
> +    if (i2c_start_transfer(s->bus, s->dr >> 1, s->dr & (0x01))) {
> +        s->sr |= CSR_RXAK;
> +    } else {
> +        s->address = s->dr;
> +        s->sr &= ~CSR_RXAK;
> +        s->sr |=  CSR_MCF; /*Byte Transfer is completed*/

In general please try to keep spaces between *s and letters:

  /* Byte transfer is completed */

> +        s->sr |=  CSR_MIF; /*Needs to be set after Byte Transfer is completed*/

This line looks longer than 80 characters. Do you think you can
configure your editor to tell you when you exceed 80? It makes life a
lot easier when the editor tells you these things.

For an example .vimrc config, use

:au BufWinEnter * highlight LineTooLong cterm=bold ctermbg=yellow
guibg=LightYellow
:au BufWinEnter * let w:m2=matchadd('LineTooLong', '\%>80v.\+', -1)

> +        mpc_i2c_irq(s);
> +    }
> +}
> +
> +static void  mpc_i2c_data_send(MPCI2CState *s)
> +{
> +    if (i2c_send(s->bus, s->dr)) {
> +        /* if the target return non zero then end the transfer */

I think the comment is too verbose. "if the target returns non zero" is
already implied by the if() above. How about

  /* End of transfer */

> +        s->sr |= CSR_RXAK;
> +        i2c_end_transfer(s->bus);
> +    } else {
> +        s->sr &= ~CSR_RXAK;
> +        s->sr |=  CSR_MCF; /* Byte Transfer is completed*/

Spaces missing at the end before asterisk (*) :).

> +        s->sr |=  CSR_MIF; /* Needs to be set after Byte Transfer is completed*/
> +        mpc_i2c_irq(s);
> +    }
> +}
> +
> +static void  mpc_i2c_data_recive(MPCI2CState *s)
> +{
> +    int ret;
> +    /* get the next byte */
> +    ret = i2c_recv(s->bus);
> +    if (ret >= 0) {
> +        s->sr |= CSR_MCF;/* Byte Transfer is completed*/
> +        s->sr |= CSR_MIF;/* Needs to be set after Byte Transfer is completed*/
> +        mpc_i2c_irq(s);
> +    } else {
> +        DPRINTF("read failed for device");
> +        ret = 0xff;
> +    }
> +    s->dr = ret;
> +}
> +
> +static uint64_t mpc_i2c_read(void *opaque, hwaddr addr, unsigned size)
> +{
> +    MPCI2CState *s = opaque;
> +    uint8_t value;
> +
> +    switch (addr) {
> +    case MPC_I2C_ADR:
> +        value = s->adr;
> +        break;
> +    case MPC_I2C_FDR:
> +        value = s->fdr;
> +        break;
> +    case MPC_I2C_CR:
> +        value = s->cr;
> +        break;
> +    case MPC_I2C_SR:
> +        value = s->sr;
> +        break;
> +    case MPC_I2C_DR:
> +        value = s->dr;
> +        if (mpc_i2c_is_master(s)) { /* master mode */
> +            if (mpc_i2c_direction_is_tx(s)) {
> +                DPRINTF("MTX is set not in recv mode\n");
> +            } else {
> +                mpc_i2c_data_recive(s);
> +            }
> +        }
> +        break;
> +    default:
> +        value = 0;
> +        DPRINTF("ERROR: Bad read addr 0x%x\n", (unsigned int)addr);
> +        break;
> +    }
> +#ifdef DEBUG_I2C
> +    DPRINTF("%s: addr " TARGET_FMT_plx " %02" PRIx32 "\n", __func__,
> +                                         addr, value);

DPRINTF only emits code when DEBUG_I2C is defined, so why check it again?

> +#endif
> +    return (uint64_t)value;
> +}
> +
> +static void mpc_i2c_write(void *opaque, hwaddr addr,
> +                            uint64_t value, unsigned size)
> +{
> +    MPCI2CState *s = opaque;
> +
> +#ifdef DEBUG_I2C
> +    DPRINTF("%s: addr " TARGET_FMT_plx " val %08" PRIx64 "\n", __func__,
> +                                             addr, value);

Same here.

> +#endif
> +    switch (addr) {
> +    case MPC_I2C_ADR:
> +        s->adr = value & CADR_MASK;
> +        break;
> +    case MPC_I2C_FDR:
> +        s->fdr = value & CFDR_MASK;
> +        break;
> +    case MPC_I2C_CR:
> +        if (mpc_i2c_is_enabled(s) && ((value & CCR_MEN) == 0)) {
> +            mpc_i2c_soft_reset(s);
> +            break;
> +        }
> +        /* normal write */
> +        s->cr = value & CCR_MASK;
> +        if (mpc_i2c_is_master(s)) { /* master mode */
> +            /* set the bus to busy after master is set as per RM*/
> +            s->sr |= CSR_MBB;
> +        } else {
> +            /* bus is not busy anymore */
> +            s->sr &= ~CSR_MBB;
> +            /* Reset the address for fresh write/read cycle*/
> +        if (s->address != CYCLE_RESET) {
> +            i2c_end_transfer(s->bus);
> +            s->address = CYCLE_RESET;
> +            }
> +        }
> +        /* For restart end the ongoing transfer */
> +        if (s->cr & CCR_RSTA) {
> +            if (s->address != CYCLE_RESET) {
> +                s->address = CYCLE_RESET;
> +                i2c_end_transfer(s->bus);
> +                s->cr &= ~CCR_RSTA;
> +            }
> +        }
> +        break;
> +    case MPC_I2C_SR:
> +        s->sr = value & CSR_MASK;
> +        /*
> +         * if the guest writes 0 to MIF/MAL then lower the interrupt
> +        */

Why a multiline comment here? Also please go through all of your
comments and double-check whether you're describing something that's not
obvious from the code flow. A comment saying

  /* If foo do x */
  if (foo) {
    x();
  }

isn't really very useful. However, a comment saying

  /* Transfer aborted */
  if (foo) {
    x();
  }

gives actual semantic value-add. I personally prefer self-documenting
code though, so in the example case I would usually try to write

  if (foo) {
    abort_transfer();
  }

which means you don't need any comment at all.

> +        if (!(s->sr & CSR_MIF) || !(s->sr & CSR_MAL)) {
> +            mpc_i2c_irq(s);
> +        }
> +        break;
> +    case MPC_I2C_DR:
> +        /* if the device is not enabled, nothing to do */
> +        if (!mpc_i2c_is_enabled(s)) {
> +            break;
> +        }
> +        s->dr = value & CDR_MASK;
> +        if (mpc_i2c_is_master(s)) { /* master mode */
> +            if (s->address == CYCLE_RESET) {
> +                mpc_i2c_address_send(s);
> +            } else {
> +                mpc_i2c_data_send(s);
> +            }
> +        }
> +        break;
> +    case MPC_I2C_DFSRR:
> +        s->dfssr = value;
> +        break;
> +    default:
> +        DPRINTF("ERROR: Bad write addr 0x%x\n", (unsigned int)addr);
> +        break;
> +    }
> +}
> +
> +static const MemoryRegionOps i2c_ops = {
> +    .read =  mpc_i2c_read,
> +    .write =  mpc_i2c_write,
> +    .valid.max_access_size = 1,
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +};
> +
> +static const VMStateDescription mpc_i2c_vmstate = {
> +    .name = TYPE_MPC_I2C,
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_UINT8(address, MPCI2CState),
> +        VMSTATE_UINT8(adr, MPCI2CState),
> +        VMSTATE_UINT8(fdr, MPCI2CState),
> +        VMSTATE_UINT8(cr, MPCI2CState),
> +        VMSTATE_UINT8(sr, MPCI2CState),
> +        VMSTATE_UINT8(dr, MPCI2CState),
> +        VMSTATE_UINT8(dfssr, MPCI2CState),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
> +static void mpc_i2c_realize(DeviceState *dev, Error **errp)
> +{
> +    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
> +    MPCI2CState  *i2c = MPC_I2C(dev);
> +
> +    sysbus_init_irq(sbd, &i2c->irq);
> +    memory_region_init_io(&i2c->iomem, OBJECT(i2c), &i2c_ops, i2c,
> +                            "mpc-i2c", 0x14);

I usually try to align the indentation with the context, so in this case
"mpc-i2c" would be aligned with &i2c-iomem. It makes it easier to grasp
what the semantic enclosure for your context is.

> +    sysbus_init_mmio(sbd, &i2c->iomem);
> +    i2c->bus = i2c_init_bus(DEVICE(dev), "i2c");
> +}
> +
> +static void mpc_i2c_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +
> +    dc->vmsd  = &mpc_i2c_vmstate ;
> +    dc->reset = mpc_i2c_reset;
> +    dc->realize = mpc_i2c_realize;
> +}
> +
> +static const TypeInfo mpc_i2c_type_info = {
> +    .name          = TYPE_MPC_I2C,
> +    .parent        = TYPE_SYS_BUS_DEVICE,
> +    .instance_size = sizeof(MPCI2CState),
> +    .class_init    = mpc_i2c_class_init,
> +};
> +
> +static void mpc_i2c_register_types(void)
> +{
> +    type_register_static(&mpc_i2c_type_info);
> +}
> +
> +type_init(mpc_i2c_register_types)
> +
> diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c
> index 2832fc0..bbe70b9 100644
> --- a/hw/ppc/e500.c
> +++ b/hw/ppc/e500.c
> @@ -39,6 +39,7 @@
>  #include "qemu/error-report.h"
>  #include "hw/platform-bus.h"
>  #include "hw/net/fsl_etsec/etsec.h"
> +#include "hw/i2c/i2c.h"
>  
>  #define EPAPR_MAGIC                (0x45504150)
>  #define BINARY_DEVICE_TREE_FILE    "mpc8544ds.dtb"
> @@ -55,6 +56,9 @@
>  #define MPC8544_CCSRBAR_SIZE       0x00100000ULL
>  #define MPC8544_MPIC_REGS_OFFSET   0x40000ULL
>  #define MPC8544_MSI_REGS_OFFSET   0x41600ULL
> +#define MPC8544_I2C_REGS_OFFSET   0x3000ULL
> +#define MPC8544_I2C_REGS_BASE     (MPC8544_CCSRBAR_BASE + \
> +                                    MPC8544_I2C_REGS_OFFSET)

I don't think you need the base, do you?

>  #define MPC8544_SERIAL0_REGS_OFFSET 0x4500ULL
>  #define MPC8544_SERIAL1_REGS_OFFSET 0x4600ULL
>  #define MPC8544_PCI_REGS_OFFSET    0x8000ULL
> @@ -65,7 +69,9 @@
>  #define MPC8544_UTIL_OFFSET        0xe0000ULL
>  #define MPC8544_SPIN_BASE          0xEF000000ULL
>  #define MPC8XXX_GPIO_OFFSET        0x000FF000ULL
>  #define MPC8XXX_GPIO_IRQ           47
> +#define MPC8544_I2C_IRQ            43
> +#define RTC_REGS_OFFSET            0x68
>  
>  struct boot_info
>  {
> @@ -127,6 +133,38 @@ static void dt_serial_create(void *fdt, unsigned long long offset,
>      }
>  }
>  
> +static void dt_rtc_create(void *fdt, const char *i2c, const char *alias)
> +{
> +    int offset = RTC_REGS_OFFSET;
> +
> +    gchar *rtc = g_strdup_printf("%s/rtc@%"PRIx32, i2c, offset);
> +    qemu_fdt_add_subnode(fdt, rtc);
> +    qemu_fdt_setprop_string(fdt, rtc, "compatible", "pericom,pt7c4338");
> +    qemu_fdt_setprop_cells(fdt, rtc, "reg", offset);
> +    qemu_fdt_setprop_string(fdt, "/aliases", alias, rtc);
> +
> +    g_free(rtc);
> +}
> +
> +static void dt_i2c_create(void *fdt, const char *soc, const char *mpic,
> +                             const char *alias)
> +{
> +    hwaddr mmio0 = MPC8544_I2C_REGS_OFFSET;
> +    int irq0 = MPC8544_I2C_IRQ;
> +
> +    gchar *i2c = g_strdup_printf("%s/i2c@%"PRIx64, soc, mmio0);
> +    qemu_fdt_add_subnode(fdt, i2c);
> +    qemu_fdt_setprop_string(fdt, i2c, "device_type", "i2c");
> +    qemu_fdt_setprop_string(fdt, i2c, "compatible", "fsl-i2c");
> +    qemu_fdt_setprop_cells(fdt, i2c, "reg", mmio0, 0x100);

Why is the region 0x100 long here, but only 0x14 in the memory region
registration?

> +    qemu_fdt_setprop_cells(fdt, i2c, "cell-index", 0);
> +    qemu_fdt_setprop_cells(fdt, i2c, "interrupts", irq0, 0x2);
> +    qemu_fdt_setprop_phandle(fdt, i2c, "interrupt-parent", mpic);
> +    qemu_fdt_setprop_string(fdt, "/aliases", alias, i2c);
> +
> +    g_free(i2c);
> +}
> +
>  static void create_dt_mpc8xxx_gpio(void *fdt, const char *soc, const char *mpic)
>  {
>      hwaddr mmio0 = MPC8XXX_GPIO_OFFSET;
> @@ -467,6 +505,10 @@ static int ppce500_load_device_tree(MachineState *machine,
>                           soc, mpic, "serial0", 0, true);
>      }
>  
> +    dt_i2c_create(fdt, soc, mpic, "i2c");
> +
> +    dt_rtc_create(fdt, "i2c", "rtc");
> +
>      snprintf(gutil, sizeof(gutil), "%s/global-utilities@%llx", soc,
>               MPC8544_UTIL_OFFSET);
>      qemu_fdt_add_subnode(fdt, gutil);
> @@ -811,6 +853,7 @@ void ppce500_init(MachineState *machine, PPCE500Params *params)
>      MemoryRegion *ccsr_addr_space;
>      SysBusDevice *s;
>      PPCE500CCSRState *ccsr;
> +    I2CBus *i2c;
>  
>      /* Setup CPUs */
>      if (machine->cpu_model == NULL) {
> @@ -893,6 +936,11 @@ void ppce500_init(MachineState *machine, PPCE500Params *params)
>                         serial_hds[1], DEVICE_BIG_ENDIAN);
>      }
>  
> +    dev = sysbus_create_simple("mpc-i2c", MPC8544_I2C_REGS_BASE,
> +                                mpic[MPC8544_I2C_IRQ]);

The i2c device is part of CCSR, no? So it should live in ccsr_addr_space
rather than have a direct map into the system address space.


Alex

> +    i2c = (I2CBus *)qdev_get_child_bus(dev, "i2c");
> +    i2c_create_slave(i2c, "ds1338", RTC_REGS_OFFSET);
> +
>      /* General Utility device */
>      dev = qdev_create(NULL, "mpc8544-guts");
>      qdev_init_nofail(dev);
>