| Message ID | 1363933984-14530-1-git-send-email-akshay.s@samsung.com |
|---|---|
| State | Accepted |
| Delegated to: | Minkyu Kang |
| Headers | show |
Hi Akshay On Thu, Mar 21, 2013 at 11:33 PM, Akshay Saraswat <akshay.s@samsung.com>wrote: > This patch enables the uart tx/rx fifo. Now that fifo is enabled, > the uart read/write functions are modfied to check the UFSTAT register > for fifo status instead of UTRSTAT (as required with fifo's enabled). > Tested by booting linux kernel. Before enabling tx/rx fifo > "Uncompressing linux" message is garbled and after enabling it is proper. > Is this because Linux enables the FIFOs? Anyway this seems fine to me, but I have a question below. > > Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com> > Signed-off-by: Akshay Saraswat <akshay.s@samsung.com> > --- > drivers/serial/serial_s5p.c | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > > diff --git a/drivers/serial/serial_s5p.c b/drivers/serial/serial_s5p.c > index 3c41242..e65125c 100644 > --- a/drivers/serial/serial_s5p.c > +++ b/drivers/serial/serial_s5p.c > @@ -30,6 +30,10 @@ > > DECLARE_GLOBAL_DATA_PTR; > > +#define RX_FIFO_COUNT_MASK 0xff > +#define RX_FIFO_FULL_MASK (1 << 8) > +#define TX_FIFO_FULL_MASK (1 << 24) > + > static inline struct s5p_uart *s5p_get_base_uart(int dev_index) > { > u32 offset = dev_index * sizeof(struct s5p_uart); > @@ -87,8 +91,8 @@ int serial_init_dev(const int dev_index) > { > struct s5p_uart *const uart = s5p_get_base_uart(dev_index); > > - /* reset and enable FIFOs, set triggers to the maximum */ > - writel(0, &uart->ufcon); > + /* enable FIFOs */ > + writel(0x1, &uart->ufcon); > It is odd that you seem to be saying that the old code did not enable FIFOs, but this code does? Or should you update your comment? > writel(0, &uart->umcon); > /* 8N1 */ > writel(0x3, &uart->ulcon); > @@ -130,7 +134,8 @@ int serial_getc_dev(const int dev_index) > struct s5p_uart *const uart = s5p_get_base_uart(dev_index); > > /* wait for character to arrive */ > - while (!(readl(&uart->utrstat) & 0x1)) { > + while (!(readl(&uart->ufstat) & (RX_FIFO_COUNT_MASK | > + RX_FIFO_FULL_MASK))) { > if (serial_err_check(dev_index, 0)) > return 0; > } > @@ -146,7 +151,7 @@ void serial_putc_dev(const char c, const int dev_index) > struct s5p_uart *const uart = s5p_get_base_uart(dev_index); > > /* wait for room in the tx FIFO */ > - while (!(readl(&uart->utrstat) & 0x2)) { > + while ((readl(&uart->ufstat) & TX_FIFO_FULL_MASK)) { > if (serial_err_check(dev_index, 1)) > return; > } > -- > 1.8.0 > > Regards, Simon
On 22/03/13 15:33, Akshay Saraswat wrote: > This patch enables the uart tx/rx fifo. Now that fifo is enabled, > the uart read/write functions are modfied to check the UFSTAT register > for fifo status instead of UTRSTAT (as required with fifo's enabled). > Tested by booting linux kernel. Before enabling tx/rx fifo > "Uncompressing linux" message is garbled and after enabling it is proper. > > Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com> > Signed-off-by: Akshay Saraswat <akshay.s@samsung.com> > --- > drivers/serial/serial_s5p.c | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > applied to u-boot-samsung. Thanks, Minkyu Kang.
diff --git a/drivers/serial/serial_s5p.c b/drivers/serial/serial_s5p.c index 3c41242..e65125c 100644 --- a/drivers/serial/serial_s5p.c +++ b/drivers/serial/serial_s5p.c @@ -30,6 +30,10 @@ DECLARE_GLOBAL_DATA_PTR; +#define RX_FIFO_COUNT_MASK 0xff +#define RX_FIFO_FULL_MASK (1 << 8) +#define TX_FIFO_FULL_MASK (1 << 24) + static inline struct s5p_uart *s5p_get_base_uart(int dev_index) { u32 offset = dev_index * sizeof(struct s5p_uart); @@ -87,8 +91,8 @@ int serial_init_dev(const int dev_index) { struct s5p_uart *const uart = s5p_get_base_uart(dev_index); - /* reset and enable FIFOs, set triggers to the maximum */ - writel(0, &uart->ufcon); + /* enable FIFOs */ + writel(0x1, &uart->ufcon); writel(0, &uart->umcon); /* 8N1 */ writel(0x3, &uart->ulcon); @@ -130,7 +134,8 @@ int serial_getc_dev(const int dev_index) struct s5p_uart *const uart = s5p_get_base_uart(dev_index); /* wait for character to arrive */ - while (!(readl(&uart->utrstat) & 0x1)) { + while (!(readl(&uart->ufstat) & (RX_FIFO_COUNT_MASK | + RX_FIFO_FULL_MASK))) { if (serial_err_check(dev_index, 0)) return 0; } @@ -146,7 +151,7 @@ void serial_putc_dev(const char c, const int dev_index) struct s5p_uart *const uart = s5p_get_base_uart(dev_index); /* wait for room in the tx FIFO */ - while (!(readl(&uart->utrstat) & 0x2)) { + while ((readl(&uart->ufstat) & TX_FIFO_FULL_MASK)) { if (serial_err_check(dev_index, 1)) return; }