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usb: Prevent RX_CTR and TX_CTR from being cleared

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When writing the USB endpoint register, USB_EP_RX_CTR (bit 15) and
USB_EP_TX_CTR (bit 7) should be set to avoid inadvertently clearing
either bit.

Prior to this patch end points could indefinately stall if the hardware
changed these bits between the time they are read and when they were
written.

Signed-off-by: George McCollister <george.mccollister@gmail.com>
This commit is contained in:
George McCollister 2014-05-29 14:07:06 -05:00 committed by Karl Palsson
parent 9eb551c127
commit 418fdd08dd
1 changed files with 9 additions and 6 deletions
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15
include/libopencm3/stm32/usb.h
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@ -206,10 +206,12 @@ LGPL License Terms @ref lgpl_license
* is why we use some helper macros for that.
*/
#define USB_SET_EP_RX_STAT(EP, STAT) \
TOG_SET_REG_BIT_MSK(USB_EP_REG(EP), USB_EP_RX_STAT_TOG_MSK, STAT)
TOG_SET_REG_BIT_MSK_AND_SET(USB_EP_REG(EP), \
USB_EP_RX_STAT_TOG_MSK, STAT, USB_EP_RX_CTR | USB_EP_TX_CTR)
#define USB_SET_EP_TX_STAT(EP, STAT) \
TOG_SET_REG_BIT_MSK(USB_EP_REG(EP), USB_EP_TX_STAT_TOG_MSK, STAT)
TOG_SET_REG_BIT_MSK_AND_SET(USB_EP_REG(EP), \
USB_EP_TX_STAT_TOG_MSK, STAT, USB_EP_RX_CTR | USB_EP_TX_CTR)
/*
* Macros for clearing and setting USB endpoint register bits that do
@ -218,14 +220,15 @@ LGPL License Terms @ref lgpl_license
* Because the register contains some bits that use the toggle
* mechanism we need a helper macro here. Otherwise the code gets really messy.
*/
#define USB_CLR_EP_NTOGGLE_BIT(EP, BIT) \
CLR_REG_BIT_MSK(USB_EP_REG(EP), USB_EP_NTOGGLE_MSK, BIT)
#define USB_CLR_EP_NTOGGLE_BIT_AND_SET(EP, BIT, EXTRA_BITS) \
CLR_REG_BIT_MSK_AND_SET(USB_EP_REG(EP), \
USB_EP_NTOGGLE_MSK, BIT, EXTRA_BITS)
#define USB_CLR_EP_RX_CTR(EP) \
USB_CLR_EP_NTOGGLE_BIT(EP, USB_EP_RX_CTR)
USB_CLR_EP_NTOGGLE_BIT_AND_SET(EP, USB_EP_RX_CTR, USB_EP_TX_CTR)
#define USB_CLR_EP_TX_CTR(EP) \
USB_CLR_EP_NTOGGLE_BIT(EP, USB_EP_TX_CTR)
USB_CLR_EP_NTOGGLE_BIT_AND_SET(EP, USB_EP_TX_CTR, USB_EP_RX_CTR)
#define USB_SET_EP_TYPE(EP, TYPE) \
SET_REG(USB_EP_REG(EP), \