[PATCH v3 04/23] serial: omap: drop DMA support
Felipe Balbi
balbi at ti.com
Thu Aug 23 06:32:44 EDT 2012
The current support is known to be broken and
a later patch will come re-adding it using
dma engine API.
Tested-by: Shubhrajyoti D <shubhrajyoti at ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar at ti.com>
Signed-off-by: Felipe Balbi <balbi at ti.com>
---
drivers/tty/serial/omap-serial.c | 330 ++-------------------------------------
1 file changed, 12 insertions(+), 318 deletions(-)
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 6ab3582..16808b6 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -33,14 +33,12 @@
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/io.h>
-#include <linux/dma-mapping.h>
#include <linux/clk.h>
#include <linux/serial_core.h>
#include <linux/irq.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>
-#include <plat/dma.h>
#include <plat/dmtimer.h>
#include <plat/omap-serial.h>
@@ -74,9 +72,6 @@
static struct uart_omap_port *ui[OMAP_MAX_HSUART_PORTS];
/* Forward declaration of functions */
-static void uart_tx_dma_callback(int lch, u16 ch_status, void *data);
-static void serial_omap_rxdma_poll(unsigned long uart_no);
-static int serial_omap_start_rxdma(struct uart_omap_port *up);
static void serial_omap_mdr1_errataset(struct uart_omap_port *up, u8 mdr1);
static struct workqueue_struct *serial_omap_uart_wq;
@@ -160,19 +155,6 @@ serial_omap_get_divisor(struct uart_port *port, unsigned int baud)
return port->uartclk/(baud * divisor);
}
-static void serial_omap_stop_rxdma(struct uart_omap_port *up)
-{
- if (up->uart_dma.rx_dma_used) {
- del_timer(&up->uart_dma.rx_timer);
- omap_stop_dma(up->uart_dma.rx_dma_channel);
- omap_free_dma(up->uart_dma.rx_dma_channel);
- up->uart_dma.rx_dma_channel = OMAP_UART_DMA_CH_FREE;
- up->uart_dma.rx_dma_used = false;
- pm_runtime_mark_last_busy(up->dev);
- pm_runtime_put_autosuspend(up->dev);
- }
-}
-
static void serial_omap_enable_ms(struct uart_port *port)
{
struct uart_omap_port *up = to_uart_omap_port(port);
@@ -188,22 +170,6 @@ static void serial_omap_enable_ms(struct uart_port *port)
static void serial_omap_stop_tx(struct uart_port *port)
{
struct uart_omap_port *up = to_uart_omap_port(port);
- struct omap_uart_port_info *pdata = up->dev->platform_data;
-
- if (up->use_dma &&
- up->uart_dma.tx_dma_channel != OMAP_UART_DMA_CH_FREE) {
- /*
- * Check if dma is still active. If yes do nothing,
- * return. Else stop dma
- */
- if (omap_get_dma_active_status(up->uart_dma.tx_dma_channel))
- return;
- omap_stop_dma(up->uart_dma.tx_dma_channel);
- omap_free_dma(up->uart_dma.tx_dma_channel);
- up->uart_dma.tx_dma_channel = OMAP_UART_DMA_CH_FREE;
- pm_runtime_mark_last_busy(up->dev);
- pm_runtime_put_autosuspend(up->dev);
- }
pm_runtime_get_sync(up->dev);
if (up->ier & UART_IER_THRI) {
@@ -211,8 +177,7 @@ static void serial_omap_stop_tx(struct uart_port *port)
serial_out(up, UART_IER, up->ier);
}
- if (!up->use_dma && pdata)
- serial_omap_set_forceidle(up);
+ serial_omap_set_forceidle(up);
pm_runtime_mark_last_busy(up->dev);
pm_runtime_put_autosuspend(up->dev);
@@ -223,8 +188,6 @@ static void serial_omap_stop_rx(struct uart_port *port)
struct uart_omap_port *up = to_uart_omap_port(port);
pm_runtime_get_sync(up->dev);
- if (up->use_dma)
- serial_omap_stop_rxdma(up);
up->ier &= ~UART_IER_RLSI;
up->port.read_status_mask &= ~UART_LSR_DR;
serial_out(up, UART_IER, up->ier);
@@ -342,67 +305,12 @@ static inline void serial_omap_enable_ier_thri(struct uart_omap_port *up)
static void serial_omap_start_tx(struct uart_port *port)
{
struct uart_omap_port *up = to_uart_omap_port(port);
- struct circ_buf *xmit;
- unsigned int start;
- int ret = 0;
-
- if (!up->use_dma) {
- pm_runtime_get_sync(up->dev);
- serial_omap_enable_ier_thri(up);
- serial_omap_set_noidle(up);
- pm_runtime_mark_last_busy(up->dev);
- pm_runtime_put_autosuspend(up->dev);
- return;
- }
-
- if (up->uart_dma.tx_dma_used)
- return;
-
- xmit = &up->port.state->xmit;
-
- if (up->uart_dma.tx_dma_channel == OMAP_UART_DMA_CH_FREE) {
- pm_runtime_get_sync(up->dev);
- ret = omap_request_dma(up->uart_dma.uart_dma_tx,
- "UART Tx DMA",
- (void *)uart_tx_dma_callback, up,
- &(up->uart_dma.tx_dma_channel));
- if (ret < 0) {
- serial_omap_enable_ier_thri(up);
- return;
- }
- }
- spin_lock(&(up->uart_dma.tx_lock));
- up->uart_dma.tx_dma_used = true;
- spin_unlock(&(up->uart_dma.tx_lock));
-
- start = up->uart_dma.tx_buf_dma_phys +
- (xmit->tail & (UART_XMIT_SIZE - 1));
-
- up->uart_dma.tx_buf_size = uart_circ_chars_pending(xmit);
- /*
- * It is a circular buffer. See if the buffer has wounded back.
- * If yes it will have to be transferred in two separate dma
- * transfers
- */
- if (start + up->uart_dma.tx_buf_size >=
- up->uart_dma.tx_buf_dma_phys + UART_XMIT_SIZE)
- up->uart_dma.tx_buf_size =
- (up->uart_dma.tx_buf_dma_phys +
- UART_XMIT_SIZE) - start;
-
- omap_set_dma_dest_params(up->uart_dma.tx_dma_channel, 0,
- OMAP_DMA_AMODE_CONSTANT,
- up->uart_dma.uart_base, 0, 0);
- omap_set_dma_src_params(up->uart_dma.tx_dma_channel, 0,
- OMAP_DMA_AMODE_POST_INC, start, 0, 0);
- omap_set_dma_transfer_params(up->uart_dma.tx_dma_channel,
- OMAP_DMA_DATA_TYPE_S8,
- up->uart_dma.tx_buf_size, 1,
- OMAP_DMA_SYNC_ELEMENT,
- up->uart_dma.uart_dma_tx, 0);
- /* FIXME: Cache maintenance needed here? */
- omap_start_dma(up->uart_dma.tx_dma_channel);
+ pm_runtime_get_sync(up->dev);
+ serial_omap_enable_ier_thri(up);
+ serial_omap_set_noidle(up);
+ pm_runtime_mark_last_busy(up->dev);
+ pm_runtime_put_autosuspend(up->dev);
}
static unsigned int check_modem_status(struct uart_omap_port *up)
@@ -455,16 +363,8 @@ static inline irqreturn_t serial_omap_irq(int irq, void *dev_id)
spin_lock_irqsave(&up->port.lock, flags);
lsr = serial_in(up, UART_LSR);
if (iir & UART_IIR_RLSI) {
- if (!up->use_dma) {
- if (lsr & UART_LSR_DR)
- receive_chars(up, &lsr);
- } else {
- up->ier &= ~(UART_IER_RDI | UART_IER_RLSI);
- serial_out(up, UART_IER, up->ier);
- if ((serial_omap_start_rxdma(up) != 0) &&
- (lsr & UART_LSR_DR))
- receive_chars(up, &lsr);
- }
+ if (lsr & UART_LSR_DR)
+ receive_chars(up, &lsr);
}
check_modem_status(up);
@@ -605,20 +505,6 @@ static int serial_omap_startup(struct uart_port *port)
spin_unlock_irqrestore(&up->port.lock, flags);
up->msr_saved_flags = 0;
- if (up->use_dma) {
- free_page((unsigned long)up->port.state->xmit.buf);
- up->port.state->xmit.buf = dma_alloc_coherent(NULL,
- UART_XMIT_SIZE,
- (dma_addr_t *)&(up->uart_dma.tx_buf_dma_phys),
- 0);
- init_timer(&(up->uart_dma.rx_timer));
- up->uart_dma.rx_timer.function = serial_omap_rxdma_poll;
- up->uart_dma.rx_timer.data = up->port.line;
- /* Currently the buffer size is 4KB. Can increase it */
- up->uart_dma.rx_buf = dma_alloc_coherent(NULL,
- up->uart_dma.rx_buf_size,
- (dma_addr_t *)&(up->uart_dma.rx_buf_dma_phys), 0);
- }
/*
* Finally, enable interrupts. Note: Modem status interrupts
* are set via set_termios(), which will be occurring imminently
@@ -666,17 +552,6 @@ static void serial_omap_shutdown(struct uart_port *port)
*/
if (serial_in(up, UART_LSR) & UART_LSR_DR)
(void) serial_in(up, UART_RX);
- if (up->use_dma) {
- dma_free_coherent(up->port.dev,
- UART_XMIT_SIZE, up->port.state->xmit.buf,
- up->uart_dma.tx_buf_dma_phys);
- up->port.state->xmit.buf = NULL;
- serial_omap_stop_rx(port);
- dma_free_coherent(up->port.dev,
- up->uart_dma.rx_buf_size, up->uart_dma.rx_buf,
- up->uart_dma.rx_buf_dma_phys);
- up->uart_dma.rx_buf = NULL;
- }
pm_runtime_put(up->dev);
free_irq(up->port.irq, up);
@@ -800,8 +675,6 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
up->fcr = UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_01 |
UART_FCR_ENABLE_FIFO;
- if (up->use_dma)
- up->fcr |= UART_FCR_DMA_SELECT;
/*
* Ok, we're now changing the port state. Do it with
@@ -877,14 +750,9 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
up->scr |= OMAP_UART_SCR_RX_TRIG_GRANU1_MASK;
- if (up->use_dma) {
- serial_out(up, UART_TI752_TLR, 0);
- up->scr |= UART_FCR_TRIGGER_4;
- } else {
- /* Set receive FIFO threshold to 1 byte */
- up->fcr &= ~OMAP_UART_FCR_RX_FIFO_TRIG_MASK;
- up->fcr |= (0x1 << OMAP_UART_FCR_RX_FIFO_TRIG_SHIFT);
- }
+ /* Set receive FIFO threshold to 1 byte */
+ up->fcr &= ~OMAP_UART_FCR_RX_FIFO_TRIG_MASK;
+ up->fcr |= (0x1 << OMAP_UART_FCR_RX_FIFO_TRIG_SHIFT);
serial_out(up, UART_FCR, up->fcr);
serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
@@ -1253,149 +1121,6 @@ static int serial_omap_resume(struct device *dev)
}
#endif
-static void serial_omap_rxdma_poll(unsigned long uart_no)
-{
- struct uart_omap_port *up = ui[uart_no];
- unsigned int curr_dma_pos, curr_transmitted_size;
- int ret = 0;
-
- curr_dma_pos = omap_get_dma_dst_pos(up->uart_dma.rx_dma_channel);
- if ((curr_dma_pos == up->uart_dma.prev_rx_dma_pos) ||
- (curr_dma_pos == 0)) {
- if (jiffies_to_msecs(jiffies - up->port_activity) <
- up->uart_dma.rx_timeout) {
- mod_timer(&up->uart_dma.rx_timer, jiffies +
- usecs_to_jiffies(up->uart_dma.rx_poll_rate));
- } else {
- serial_omap_stop_rxdma(up);
- up->ier |= (UART_IER_RDI | UART_IER_RLSI);
- serial_out(up, UART_IER, up->ier);
- }
- return;
- }
-
- curr_transmitted_size = curr_dma_pos -
- up->uart_dma.prev_rx_dma_pos;
- up->port.icount.rx += curr_transmitted_size;
- tty_insert_flip_string(up->port.state->port.tty,
- up->uart_dma.rx_buf +
- (up->uart_dma.prev_rx_dma_pos -
- up->uart_dma.rx_buf_dma_phys),
- curr_transmitted_size);
- tty_flip_buffer_push(up->port.state->port.tty);
- up->uart_dma.prev_rx_dma_pos = curr_dma_pos;
- if (up->uart_dma.rx_buf_size +
- up->uart_dma.rx_buf_dma_phys == curr_dma_pos) {
- ret = serial_omap_start_rxdma(up);
- if (ret < 0) {
- serial_omap_stop_rxdma(up);
- up->ier |= (UART_IER_RDI | UART_IER_RLSI);
- serial_out(up, UART_IER, up->ier);
- }
- } else {
- mod_timer(&up->uart_dma.rx_timer, jiffies +
- usecs_to_jiffies(up->uart_dma.rx_poll_rate));
- }
- up->port_activity = jiffies;
-}
-
-static void uart_rx_dma_callback(int lch, u16 ch_status, void *data)
-{
- return;
-}
-
-static int serial_omap_start_rxdma(struct uart_omap_port *up)
-{
- int ret = 0;
-
- if (up->uart_dma.rx_dma_channel == -1) {
- pm_runtime_get_sync(up->dev);
- ret = omap_request_dma(up->uart_dma.uart_dma_rx,
- "UART Rx DMA",
- (void *)uart_rx_dma_callback, up,
- &(up->uart_dma.rx_dma_channel));
- if (ret < 0)
- return ret;
-
- omap_set_dma_src_params(up->uart_dma.rx_dma_channel, 0,
- OMAP_DMA_AMODE_CONSTANT,
- up->uart_dma.uart_base, 0, 0);
- omap_set_dma_dest_params(up->uart_dma.rx_dma_channel, 0,
- OMAP_DMA_AMODE_POST_INC,
- up->uart_dma.rx_buf_dma_phys, 0, 0);
- omap_set_dma_transfer_params(up->uart_dma.rx_dma_channel,
- OMAP_DMA_DATA_TYPE_S8,
- up->uart_dma.rx_buf_size, 1,
- OMAP_DMA_SYNC_ELEMENT,
- up->uart_dma.uart_dma_rx, 0);
- }
- up->uart_dma.prev_rx_dma_pos = up->uart_dma.rx_buf_dma_phys;
- /* FIXME: Cache maintenance needed here? */
- omap_start_dma(up->uart_dma.rx_dma_channel);
- mod_timer(&up->uart_dma.rx_timer, jiffies +
- usecs_to_jiffies(up->uart_dma.rx_poll_rate));
- up->uart_dma.rx_dma_used = true;
- return ret;
-}
-
-static void serial_omap_continue_tx(struct uart_omap_port *up)
-{
- struct circ_buf *xmit = &up->port.state->xmit;
- unsigned int start = up->uart_dma.tx_buf_dma_phys
- + (xmit->tail & (UART_XMIT_SIZE - 1));
-
- if (uart_circ_empty(xmit))
- return;
-
- up->uart_dma.tx_buf_size = uart_circ_chars_pending(xmit);
- /*
- * It is a circular buffer. See if the buffer has wounded back.
- * If yes it will have to be transferred in two separate dma
- * transfers
- */
- if (start + up->uart_dma.tx_buf_size >=
- up->uart_dma.tx_buf_dma_phys + UART_XMIT_SIZE)
- up->uart_dma.tx_buf_size =
- (up->uart_dma.tx_buf_dma_phys + UART_XMIT_SIZE) - start;
- omap_set_dma_dest_params(up->uart_dma.tx_dma_channel, 0,
- OMAP_DMA_AMODE_CONSTANT,
- up->uart_dma.uart_base, 0, 0);
- omap_set_dma_src_params(up->uart_dma.tx_dma_channel, 0,
- OMAP_DMA_AMODE_POST_INC, start, 0, 0);
- omap_set_dma_transfer_params(up->uart_dma.tx_dma_channel,
- OMAP_DMA_DATA_TYPE_S8,
- up->uart_dma.tx_buf_size, 1,
- OMAP_DMA_SYNC_ELEMENT,
- up->uart_dma.uart_dma_tx, 0);
- /* FIXME: Cache maintenance needed here? */
- omap_start_dma(up->uart_dma.tx_dma_channel);
-}
-
-static void uart_tx_dma_callback(int lch, u16 ch_status, void *data)
-{
- struct uart_omap_port *up = data;
- struct circ_buf *xmit = &up->port.state->xmit;
-
- xmit->tail = (xmit->tail + up->uart_dma.tx_buf_size) & \
- (UART_XMIT_SIZE - 1);
- up->port.icount.tx += up->uart_dma.tx_buf_size;
-
- if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
- uart_write_wakeup(&up->port);
-
- if (uart_circ_empty(xmit)) {
- spin_lock(&(up->uart_dma.tx_lock));
- serial_omap_stop_tx(&up->port);
- up->uart_dma.tx_dma_used = false;
- spin_unlock(&(up->uart_dma.tx_lock));
- } else {
- omap_stop_dma(up->uart_dma.tx_dma_channel);
- serial_omap_continue_tx(up);
- }
- up->port_activity = jiffies;
- return;
-}
-
static void omap_serial_fill_features_erratas(struct uart_omap_port *up)
{
u32 mvr, scheme;
@@ -1465,7 +1190,7 @@ static struct omap_uart_port_info *of_get_uart_port_info(struct device *dev)
static int serial_omap_probe(struct platform_device *pdev)
{
struct uart_omap_port *up;
- struct resource *mem, *irq, *dma_tx, *dma_rx;
+ struct resource *mem, *irq;
struct omap_uart_port_info *omap_up_info = pdev->dev.platform_data;
int ret = -ENOSPC;
@@ -1490,14 +1215,6 @@ static int serial_omap_probe(struct platform_device *pdev)
return -EBUSY;
}
- dma_rx = platform_get_resource_byname(pdev, IORESOURCE_DMA, "rx");
- if (!dma_rx)
- return -ENXIO;
-
- dma_tx = platform_get_resource_byname(pdev, IORESOURCE_DMA, "tx");
- if (!dma_tx)
- return -ENXIO;
-
up = devm_kzalloc(&pdev->dev, sizeof(*up), GFP_KERNEL);
if (!up)
return -ENOMEM;
@@ -1541,20 +1258,6 @@ static int serial_omap_probe(struct platform_device *pdev)
dev_warn(&pdev->dev, "No clock speed specified: using default:"
"%d\n", DEFAULT_CLK_SPEED);
}
- up->uart_dma.uart_base = mem->start;
-
- if (omap_up_info->dma_enabled) {
- up->uart_dma.uart_dma_tx = dma_tx->start;
- up->uart_dma.uart_dma_rx = dma_rx->start;
- up->use_dma = 1;
- up->uart_dma.rx_buf_size = omap_up_info->dma_rx_buf_size;
- up->uart_dma.rx_timeout = omap_up_info->dma_rx_timeout;
- up->uart_dma.rx_poll_rate = omap_up_info->dma_rx_poll_rate;
- spin_lock_init(&(up->uart_dma.tx_lock));
- spin_lock_init(&(up->uart_dma.rx_lock));
- up->uart_dma.tx_dma_channel = OMAP_UART_DMA_CH_FREE;
- up->uart_dma.rx_dma_channel = OMAP_UART_DMA_CH_FREE;
- }
up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
up->calc_latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
@@ -1697,10 +1400,6 @@ static int serial_omap_runtime_suspend(struct device *dev)
}
}
- /* Errata i291 */
- if (up->use_dma && (up->errata & UART_ERRATA_i291_DMA_FORCEIDLE))
- serial_omap_set_forceidle(up);
-
up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
schedule_work(&up->qos_work);
@@ -1718,11 +1417,6 @@ static int serial_omap_runtime_resume(struct device *dev)
if (up->context_loss_cnt != loss_cnt)
serial_omap_restore_context(up);
- /* Errata i291 */
- if ((up->errata & UART_ERRATA_i291_DMA_FORCEIDLE) &&
- up->use_dma)
- serial_omap_set_noidle(up);
-
up->latency = up->calc_latency;
schedule_work(&up->qos_work);
}
--
1.7.12.rc3
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