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authorJon Nettleton <jon@solid-run.com>2018-02-27 15:53:12 +0000
committerDavid S. Miller <davem@davemloft.net>2018-02-28 11:07:11 -0500
commit3bb35261c74e394aa42d0c636d2608093a1e3309 (patch)
treeb16ee97e936e7db44364d28641871f31db2088ce
parent66f5325ce93a2e6fd726fca31fea91baf36a392e (diff)
downloadlinux-3bb35261c74e394aa42d0c636d2608093a1e3309.tar.bz2
sfp: add high power module support
This patch is the result of work by both Jon Nettleton and Russell King. Jon wrote the original patch, adding support for SFP modules which require a power level greater than '1'. Russell's changes: - Fix the power levels for big-endian, and make the code flow better. - Convert to use device_property_read_u8() - Warn for power levels exceeding host level SFF-8431 says: "To avoid exceeding system power supply limits and cooling capacity, all modules at power up by default shall operate with up to 1.0 W. Hosts supporting Power Level II or III operation may enable a Power Level II or III module through the 2-wire interface. Power Level II or III modules shall assert the power level declaration bit of SFF-8472." Print a warning for modules that exceed the host power level, and leave them operating in power level 1. - Fix i2c write The first byte of any write after the bus address is always the device address. In order to write a value to device D, address I, value V, we need to generate on the bus: S DDDDDDDD A IIIIIIII A VVVVVVVV A P where S = start, R = restart, A = ack, P = stop. Splitting this as two: S DDDDDDDD A IIIIIIII A R DDDDDDDD A VVVVVVVV A P results in the device's address register being written first by I and then by V - the addressed register within the device is not written. - Avoid power mode switching if 0xa2 is not implemented Some modules indicate that they support power level II or power level III, but do not implement address 0xa2, meaning that the bit to set them to high power mode is not accessible. These modules appear to have the sff8472_compliance field set to zero, and also do not implement diagnostics. Detect this, but also ensure that the module does not require the address switching mode, which we do not implement. - Use mW for power level rather than power level number. - Fix high power mode transition We must not switch to SFP_MOD_PRESENT state until we have finished initialising, because the remaining state machines check for that state. Add SFP_MOD_HPOWER as an intermediate state. - Use definition for I2C register address rather than constant. Signed-off-by: Jon Nettleton <jon@solid-run.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/phy/sfp.c150
1 files changed, 132 insertions, 18 deletions
diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index 6c7d9289078d..83bf4959b043 100644
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -42,6 +42,7 @@ enum {
SFP_MOD_EMPTY = 0,
SFP_MOD_PROBE,
+ SFP_MOD_HPOWER,
SFP_MOD_PRESENT,
SFP_MOD_ERROR,
@@ -86,6 +87,7 @@ static const enum gpiod_flags gpio_flags[] = {
* access the I2C EEPROM. However, Avago modules require 300ms.
*/
#define T_PROBE_INIT msecs_to_jiffies(300)
+#define T_HPOWER_LEVEL msecs_to_jiffies(300)
#define T_PROBE_RETRY msecs_to_jiffies(100)
/* SFP modules appear to always have their PHY configured for bus address
@@ -110,10 +112,12 @@ struct sfp {
struct sfp_bus *sfp_bus;
struct phy_device *mod_phy;
const struct sff_data *type;
+ u32 max_power_mW;
unsigned int (*get_state)(struct sfp *);
void (*set_state)(struct sfp *, unsigned int);
int (*read)(struct sfp *, bool, u8, void *, size_t);
+ int (*write)(struct sfp *, bool, u8, void *, size_t);
struct gpio_desc *gpio[GPIO_MAX];
@@ -201,10 +205,11 @@ static void sfp_gpio_set_state(struct sfp *sfp, unsigned int state)
}
}
-static int sfp__i2c_read(struct i2c_adapter *i2c, u8 bus_addr, u8 dev_addr,
- void *buf, size_t len)
+static int sfp_i2c_read(struct sfp *sfp, bool a2, u8 dev_addr, void *buf,
+ size_t len)
{
struct i2c_msg msgs[2];
+ u8 bus_addr = a2 ? 0x51 : 0x50;
int ret;
msgs[0].addr = bus_addr;
@@ -216,17 +221,38 @@ static int sfp__i2c_read(struct i2c_adapter *i2c, u8 bus_addr, u8 dev_addr,
msgs[1].len = len;
msgs[1].buf = buf;
- ret = i2c_transfer(i2c, msgs, ARRAY_SIZE(msgs));
+ ret = i2c_transfer(sfp->i2c, msgs, ARRAY_SIZE(msgs));
if (ret < 0)
return ret;
return ret == ARRAY_SIZE(msgs) ? len : 0;
}
-static int sfp_i2c_read(struct sfp *sfp, bool a2, u8 addr, void *buf,
- size_t len)
+static int sfp_i2c_write(struct sfp *sfp, bool a2, u8 dev_addr, void *buf,
+ size_t len)
{
- return sfp__i2c_read(sfp->i2c, a2 ? 0x51 : 0x50, addr, buf, len);
+ struct i2c_msg msgs[1];
+ u8 bus_addr = a2 ? 0x51 : 0x50;
+ int ret;
+
+ msgs[0].addr = bus_addr;
+ msgs[0].flags = 0;
+ msgs[0].len = 1 + len;
+ msgs[0].buf = kmalloc(1 + len, GFP_KERNEL);
+ if (!msgs[0].buf)
+ return -ENOMEM;
+
+ msgs[0].buf[0] = dev_addr;
+ memcpy(&msgs[0].buf[1], buf, len);
+
+ ret = i2c_transfer(sfp->i2c, msgs, ARRAY_SIZE(msgs));
+
+ kfree(msgs[0].buf);
+
+ if (ret < 0)
+ return ret;
+
+ return ret == ARRAY_SIZE(msgs) ? len : 0;
}
static int sfp_i2c_configure(struct sfp *sfp, struct i2c_adapter *i2c)
@@ -239,6 +265,7 @@ static int sfp_i2c_configure(struct sfp *sfp, struct i2c_adapter *i2c)
sfp->i2c = i2c;
sfp->read = sfp_i2c_read;
+ sfp->write = sfp_i2c_write;
i2c_mii = mdio_i2c_alloc(sfp->dev, i2c);
if (IS_ERR(i2c_mii))
@@ -274,6 +301,11 @@ static int sfp_read(struct sfp *sfp, bool a2, u8 addr, void *buf, size_t len)
return sfp->read(sfp, a2, addr, buf, len);
}
+static int sfp_write(struct sfp *sfp, bool a2, u8 addr, void *buf, size_t len)
+{
+ return sfp->write(sfp, a2, addr, buf, len);
+}
+
static unsigned int sfp_check(void *buf, size_t len)
{
u8 *p, check;
@@ -462,21 +494,83 @@ static void sfp_sm_mod_init(struct sfp *sfp)
sfp_sm_probe_phy(sfp);
}
+static int sfp_sm_mod_hpower(struct sfp *sfp)
+{
+ u32 power;
+ u8 val;
+ int err;
+
+ power = 1000;
+ if (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_POWER_DECL))
+ power = 1500;
+ if (sfp->id.ext.options & cpu_to_be16(SFP_OPTIONS_HIGH_POWER_LEVEL))
+ power = 2000;
+
+ if (sfp->id.ext.sff8472_compliance == SFP_SFF8472_COMPLIANCE_NONE &&
+ (sfp->id.ext.diagmon & (SFP_DIAGMON_DDM | SFP_DIAGMON_ADDRMODE)) !=
+ SFP_DIAGMON_DDM) {
+ /* The module appears not to implement bus address 0xa2,
+ * or requires an address change sequence, so assume that
+ * the module powers up in the indicated power mode.
+ */
+ if (power > sfp->max_power_mW) {
+ dev_err(sfp->dev,
+ "Host does not support %u.%uW modules\n",
+ power / 1000, (power / 100) % 10);
+ return -EINVAL;
+ }
+ return 0;
+ }
+
+ if (power > sfp->max_power_mW) {
+ dev_warn(sfp->dev,
+ "Host does not support %u.%uW modules, module left in power mode 1\n",
+ power / 1000, (power / 100) % 10);
+ return 0;
+ }
+
+ if (power <= 1000)
+ return 0;
+
+ err = sfp_read(sfp, true, SFP_EXT_STATUS, &val, sizeof(val));
+ if (err != sizeof(val)) {
+ dev_err(sfp->dev, "Failed to read EEPROM: %d\n", err);
+ err = -EAGAIN;
+ goto err;
+ }
+
+ val |= BIT(0);
+
+ err = sfp_write(sfp, true, SFP_EXT_STATUS, &val, sizeof(val));
+ if (err != sizeof(val)) {
+ dev_err(sfp->dev, "Failed to write EEPROM: %d\n", err);
+ err = -EAGAIN;
+ goto err;
+ }
+
+ dev_info(sfp->dev, "Module switched to %u.%uW power level\n",
+ power / 1000, (power / 100) % 10);
+ return T_HPOWER_LEVEL;
+
+err:
+ return err;
+}
+
static int sfp_sm_mod_probe(struct sfp *sfp)
{
/* SFP module inserted - read I2C data */
struct sfp_eeprom_id id;
u8 check;
- int err;
+ int ret;
- err = sfp_read(sfp, false, 0, &id, sizeof(id));
- if (err < 0) {
- dev_err(sfp->dev, "failed to read EEPROM: %d\n", err);
+ ret = sfp_read(sfp, false, 0, &id, sizeof(id));
+ if (ret < 0) {
+ dev_err(sfp->dev, "failed to read EEPROM: %d\n", ret);
return -EAGAIN;
}
- if (err != sizeof(id)) {
- dev_err(sfp->dev, "EEPROM short read: %d\n", err);
+ if (ret != sizeof(id)) {
+ dev_err(sfp->dev, "EEPROM short read: %d\n", ret);
return -EAGAIN;
}
@@ -521,7 +615,11 @@ static int sfp_sm_mod_probe(struct sfp *sfp)
dev_warn(sfp->dev,
"module address swap to access page 0xA2 is not supported.\n");
- return sfp_module_insert(sfp->sfp_bus, &sfp->id);
+ ret = sfp_module_insert(sfp->sfp_bus, &sfp->id);
+ if (ret < 0)
+ return ret;
+
+ return sfp_sm_mod_hpower(sfp);
}
static void sfp_sm_mod_remove(struct sfp *sfp)
@@ -560,17 +658,25 @@ static void sfp_sm_event(struct sfp *sfp, unsigned int event)
if (event == SFP_E_REMOVE) {
sfp_sm_ins_next(sfp, SFP_MOD_EMPTY, 0);
} else if (event == SFP_E_TIMEOUT) {
- int err = sfp_sm_mod_probe(sfp);
+ int val = sfp_sm_mod_probe(sfp);
- if (err == 0)
+ if (val == 0)
sfp_sm_ins_next(sfp, SFP_MOD_PRESENT, 0);
- else if (err == -EAGAIN)
- sfp_sm_set_timer(sfp, T_PROBE_RETRY);
- else
+ else if (val > 0)
+ sfp_sm_ins_next(sfp, SFP_MOD_HPOWER, val);
+ else if (val != -EAGAIN)
sfp_sm_ins_next(sfp, SFP_MOD_ERROR, 0);
+ else
+ sfp_sm_set_timer(sfp, T_PROBE_RETRY);
}
break;
+ case SFP_MOD_HPOWER:
+ if (event == SFP_E_TIMEOUT) {
+ sfp_sm_ins_next(sfp, SFP_MOD_PRESENT, 0);
+ break;
+ }
+ /* fallthrough */
case SFP_MOD_PRESENT:
case SFP_MOD_ERROR:
if (event == SFP_E_REMOVE) {
@@ -889,6 +995,14 @@ static int sfp_probe(struct platform_device *pdev)
if (!(sfp->gpio[GPIO_MODDEF0]))
sfp->get_state = sff_gpio_get_state;
+ device_property_read_u32(&pdev->dev, "maximum-power-milliwatt",
+ &sfp->max_power_mW);
+ if (!sfp->max_power_mW)
+ sfp->max_power_mW = 1000;
+
+ dev_info(sfp->dev, "Host maximum power %u.%uW\n",
+ sfp->max_power_mW / 1000, (sfp->max_power_mW / 100) % 10);
+
sfp->sfp_bus = sfp_register_socket(sfp->dev, sfp, &sfp_module_ops);
if (!sfp->sfp_bus)
return -ENOMEM;