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authorMichael Davidsaver <mdavidsaver@gmail.com>2017-11-19 21:24:17 -0600
committerDavid Gibson <david@gibson.dropbear.id.au>2017-12-15 09:49:23 +1100
commit5d8424dbd3e8335ea3d57f64eaa603c8fc80706f (patch)
tree4ee53549c72b12b40fe4adf9b1e7255273f90aee /hw/nvram
parente75ce32a75ba2fe78579882cfa06590edec2cd4a (diff)
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nvram: add AT24Cx i2c eeprom
Signed-off-by: Michael Davidsaver <mdavidsaver@gmail.com> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Diffstat (limited to 'hw/nvram')
-rw-r--r--hw/nvram/Makefile.objs1
-rw-r--r--hw/nvram/eeprom_at24c.c205
2 files changed, 206 insertions, 0 deletions
diff --git a/hw/nvram/Makefile.objs b/hw/nvram/Makefile.objs
index c018f6b..0f4ee71 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 0000000..efa3621
--- /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)