Re: [Qemu-devel] [PATCH 09/12] nvram: add AT24Cx i2c eeprom

[David Gibson <david@gibson.dropbear.id.au>]

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On Sun, Nov 19, 2017 at 09:24:17PM -0600, Michael Davidsaver wrote:
> Signed-off-by: Michael Davidsaver <mdavidsaver@gmail.com>

Applied to ppc-for-2.12.

> ---
>  hw/nvram/Makefile.objs  |   1 +
>  hw/nvram/eeprom_at24c.c | 205 ++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 206 insertions(+)
>  create mode 100644 hw/nvram/eeprom_at24c.c
> 
> diff --git a/hw/nvram/Makefile.objs b/hw/nvram/Makefile.objs
> index c018f6b2ff..0f4ee71dcb 100644
> --- a/hw/nvram/Makefile.objs
> +++ b/hw/nvram/Makefile.objs
> @@ -1,5 +1,6 @@
>  common-obj-$(CONFIG_DS1225Y) += ds1225y.o
>  common-obj-y += eeprom93xx.o
> +common-obj-y += eeprom_at24c.o
>  common-obj-y += fw_cfg.o
>  common-obj-y += chrp_nvram.o
>  common-obj-$(CONFIG_MAC_NVRAM) += mac_nvram.o
> diff --git a/hw/nvram/eeprom_at24c.c b/hw/nvram/eeprom_at24c.c
> new file mode 100644
> index 0000000000..efa3621ac6
> --- /dev/null
> +++ b/hw/nvram/eeprom_at24c.c
> @@ -0,0 +1,205 @@
> +/*
> + * *AT24C* series I2C EEPROM
> + *
> + * Copyright (c) 2015 Michael Davidsaver
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2.  See
> + * the LICENSE file in the top-level directory.
> + */
> +
> +#include <string.h>
> +
> +#include "qemu/osdep.h"
> +#include "qapi/error.h"
> +#include "hw/hw.h"
> +#include "hw/i2c/i2c.h"
> +#include "sysemu/block-backend.h"
> +
> +/* #define DEBUG_AT24C */
> +
> +#ifdef DEBUG_AT24C
> +#define DPRINTK(FMT, ...) printf(TYPE_AT24C_EE " : " FMT, ## __VA_ARGS__)
> +#else
> +#define DPRINTK(FMT, ...) do {} while (0)
> +#endif
> +
> +#define ERR(FMT, ...) fprintf(stderr, TYPE_AT24C_EE " : " FMT, \
> +                            ## __VA_ARGS__)
> +
> +#define TYPE_AT24C_EE "at24c-eeprom"
> +#define AT24C_EE(obj) OBJECT_CHECK(EEPROMState, (obj), TYPE_AT24C_EE)
> +
> +typedef struct EEPROMState {
> +    I2CSlave parent_obj;
> +
> +    /* address counter */
> +    uint16_t cur;
> +    /* total size in bytes */
> +    uint32_t rsize;
> +    bool writable;
> +    /* cells changed since last START? */
> +    bool changed;
> +    /* during WRITE, # of address bytes transfered */
> +    uint8_t haveaddr;
> +
> +    uint8_t *mem;
> +
> +    BlockBackend *blk;
> +} EEPROMState;
> +
> +static
> +int at24c_eeprom_event(I2CSlave *s, enum i2c_event event)
> +{
> +    EEPROMState *ee = container_of(s, EEPROMState, parent_obj);
> +
> +    switch (event) {
> +    case I2C_START_SEND:
> +    case I2C_START_RECV:
> +    case I2C_FINISH:
> +        ee->haveaddr = 0;
> +        DPRINTK("clear\n");
> +        if (ee->blk && ee->changed) {
> +            int len = blk_pwrite(ee->blk, 0, ee->mem, ee->rsize, 0);
> +            if (len != ee->rsize) {
> +                ERR(TYPE_AT24C_EE
> +                        " : failed to write backing file\n");
> +            }
> +            DPRINTK("Wrote to backing file\n");
> +        }
> +        ee->changed = false;
> +        break;
> +    case I2C_NACK:
> +        break;
> +    }
> +    return 0;
> +}
> +
> +static
> +int at24c_eeprom_recv(I2CSlave *s)
> +{
> +    EEPROMState *ee = AT24C_EE(s);
> +    int ret;
> +
> +    ret = ee->mem[ee->cur];
> +
> +    ee->cur = (ee->cur + 1u) % ee->rsize;
> +    DPRINTK("Recv %02x %c\n", ret, ret);
> +
> +    return ret;
> +}
> +
> +static
> +int at24c_eeprom_send(I2CSlave *s, uint8_t data)
> +{
> +    EEPROMState *ee = AT24C_EE(s);
> +
> +    if (ee->haveaddr < 2) {
> +        ee->cur <<= 8;
> +        ee->cur |= data;
> +        ee->haveaddr++;
> +        if (ee->haveaddr == 2) {
> +            ee->cur %= ee->rsize;
> +            DPRINTK("Set pointer %04x\n", ee->cur);
> +        }
> +
> +    } else {
> +        if (ee->writable) {
> +            DPRINTK("Send %02x\n", data);
> +            ee->mem[ee->cur] = data;
> +            ee->changed = true;
> +        } else {
> +            DPRINTK("Send error %02x read-only\n", data);
> +        }
> +        ee->cur = (ee->cur + 1u) % ee->rsize;
> +
> +    }
> +
> +    return 0;
> +}
> +
> +static
> +int at24c_eeprom_init(I2CSlave *i2c)
> +{
> +    EEPROMState *ee = AT24C_EE(i2c);
> +
> +    ee->mem = g_malloc0(ee->rsize);
> +
> +    if (ee->blk) {
> +        int64_t len = blk_getlength(ee->blk);
> +
> +        if (len != ee->rsize) {
> +            ERR(TYPE_AT24C_EE " : Backing file size %lu != %u\n",
> +                    (unsigned long)len, (unsigned)ee->rsize);
> +            exit(1);
> +        }
> +
> +        if (blk_set_perm(ee->blk, BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE,
> +                         BLK_PERM_ALL, &error_fatal) < 0)
> +        {
> +            ERR(TYPE_AT24C_EE
> +                    " : Backing file incorrect permission\n");
> +            exit(1);
> +        }
> +    }
> +    return 0;
> +}
> +
> +static
> +void at24c_eeprom_reset(DeviceState *state)
> +{
> +    EEPROMState *ee = AT24C_EE(state);
> +
> +    ee->changed = false;
> +    ee->cur = 0;
> +    ee->haveaddr = 0;
> +
> +    memset(ee->mem, 0, ee->rsize);
> +
> +    if (ee->blk) {
> +        int len = blk_pread(ee->blk, 0, ee->mem, ee->rsize);
> +
> +        if (len != ee->rsize) {
> +            ERR(TYPE_AT24C_EE
> +                    " : Failed initial sync with backing file\n");
> +        }
> +        DPRINTK("Reset read backing file\n");
> +    }
> +}
> +
> +static Property at24c_eeprom_props[] = {
> +    DEFINE_PROP_UINT32("rom-size", EEPROMState, rsize, 0),
> +    DEFINE_PROP_BOOL("writable", EEPROMState, writable, true),
> +    DEFINE_PROP_DRIVE("drive", EEPROMState, blk),
> +    DEFINE_PROP_END_OF_LIST()
> +};
> +
> +static
> +void at24c_eeprom_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +    I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
> +
> +    k->init = &at24c_eeprom_init;
> +    k->event = &at24c_eeprom_event;
> +    k->recv = &at24c_eeprom_recv;
> +    k->send = &at24c_eeprom_send;
> +
> +    dc->props = at24c_eeprom_props;
> +    dc->reset = at24c_eeprom_reset;
> +}
> +
> +static
> +const TypeInfo at24c_eeprom_type = {
> +    .name = TYPE_AT24C_EE,
> +    .parent = TYPE_I2C_SLAVE,
> +    .instance_size = sizeof(EEPROMState),
> +    .class_size = sizeof(I2CSlaveClass),
> +    .class_init = at24c_eeprom_class_init,
> +};
> +
> +static void at24c_eeprom_register(void)
> +{
> +    type_register_static(&at24c_eeprom_type);
> +}
> +
> +type_init(at24c_eeprom_register)

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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