[PATCH 07/20] sfc: SFN4111T: Fix GPIO sharing between I2C and FLASH_CFG_1
From: Ben Hutchings <hidden>
Date: 2009-01-29 19:18:08
Subsystem:
networking drivers, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Change sfn4111t_reset() to change only GPIO output enables so that it doesn't break subsequent I2C operations. Update comments to explain exactly what we're doing. Add a short sleep to make sure the FLASH_CFG_1 value is latched before any subsequent I2C operations. Signed-off-by: Ben Hutchings <redacted> --- drivers/net/sfc/sfe4001.c | 15 +++++++++------ 1 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/net/sfc/sfe4001.c b/drivers/net/sfc/sfe4001.c
index 2e9b4b4..95bb935 100644
--- a/drivers/net/sfc/sfe4001.c
+++ b/drivers/net/sfc/sfe4001.c@@ -186,19 +186,22 @@ static int sfn4111t_reset(struct efx_nic *efx) { efx_oword_t reg; - /* GPIO pins are also used for I2C, so block that temporarily */ + /* GPIO 3 and the GPIO register are shared with I2C, so block that */ mutex_lock(&efx->i2c_adap.bus_lock); + /* Pull RST_N (GPIO 2) low then let it up again, setting the + * FLASH_CFG_1 strap (GPIO 3) appropriately. Only change the + * output enables; the output levels should always be 0 (low) + * and we rely on external pull-ups. */ falcon_read(efx, ®, GPIO_CTL_REG_KER); EFX_SET_OWORD_FIELD(reg, GPIO2_OEN, true); - EFX_SET_OWORD_FIELD(reg, GPIO2_OUT, false); falcon_write(efx, ®, GPIO_CTL_REG_KER); msleep(1000); - EFX_SET_OWORD_FIELD(reg, GPIO2_OUT, true); - EFX_SET_OWORD_FIELD(reg, GPIO3_OEN, true); - EFX_SET_OWORD_FIELD(reg, GPIO3_OUT, - !(efx->phy_mode & PHY_MODE_SPECIAL)); + EFX_SET_OWORD_FIELD(reg, GPIO2_OEN, false); + EFX_SET_OWORD_FIELD(reg, GPIO3_OEN, + !!(efx->phy_mode & PHY_MODE_SPECIAL)); falcon_write(efx, ®, GPIO_CTL_REG_KER); + msleep(1); mutex_unlock(&efx->i2c_adap.bus_lock);
--
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.