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fsl_lpuart.c
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fsl_lpuart.c
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// SPDX-License-Identifier: GPL-2.0+
/*
* Freescale lpuart serial port driver
*
* Copyright 2012-2014 Freescale Semiconductor, Inc.
*/
#include <linux/clk.h>
#include <linux/console.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/dmapool.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_dma.h>
#include <linux/pinctrl/consumer.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>
#include <linux/serial_core.h>
#include <linux/slab.h>
#include <linux/tty_flip.h>
/* All registers are 8-bit width */
#define UARTBDH 0x00
#define UARTBDL 0x01
#define UARTCR1 0x02
#define UARTCR2 0x03
#define UARTSR1 0x04
#define UARTCR3 0x06
#define UARTDR 0x07
#define UARTCR4 0x0a
#define UARTCR5 0x0b
#define UARTMODEM 0x0d
#define UARTPFIFO 0x10
#define UARTCFIFO 0x11
#define UARTSFIFO 0x12
#define UARTTWFIFO 0x13
#define UARTTCFIFO 0x14
#define UARTRWFIFO 0x15
#define UARTBDH_LBKDIE 0x80
#define UARTBDH_RXEDGIE 0x40
#define UARTBDH_SBR_MASK 0x1f
#define UARTCR1_LOOPS 0x80
#define UARTCR1_RSRC 0x20
#define UARTCR1_M 0x10
#define UARTCR1_WAKE 0x08
#define UARTCR1_ILT 0x04
#define UARTCR1_PE 0x02
#define UARTCR1_PT 0x01
#define UARTCR2_TIE 0x80
#define UARTCR2_TCIE 0x40
#define UARTCR2_RIE 0x20
#define UARTCR2_ILIE 0x10
#define UARTCR2_TE 0x08
#define UARTCR2_RE 0x04
#define UARTCR2_RWU 0x02
#define UARTCR2_SBK 0x01
#define UARTSR1_TDRE 0x80
#define UARTSR1_TC 0x40
#define UARTSR1_RDRF 0x20
#define UARTSR1_IDLE 0x10
#define UARTSR1_OR 0x08
#define UARTSR1_NF 0x04
#define UARTSR1_FE 0x02
#define UARTSR1_PE 0x01
#define UARTCR3_R8 0x80
#define UARTCR3_T8 0x40
#define UARTCR3_TXDIR 0x20
#define UARTCR3_TXINV 0x10
#define UARTCR3_ORIE 0x08
#define UARTCR3_NEIE 0x04
#define UARTCR3_FEIE 0x02
#define UARTCR3_PEIE 0x01
#define UARTCR4_MAEN1 0x80
#define UARTCR4_MAEN2 0x40
#define UARTCR4_M10 0x20
#define UARTCR4_BRFA_MASK 0x1f
#define UARTCR4_BRFA_OFF 0
#define UARTCR5_TDMAS 0x80
#define UARTCR5_RDMAS 0x20
#define UARTMODEM_RXRTSE 0x08
#define UARTMODEM_TXRTSPOL 0x04
#define UARTMODEM_TXRTSE 0x02
#define UARTMODEM_TXCTSE 0x01
#define UARTPFIFO_TXFE 0x80
#define UARTPFIFO_FIFOSIZE_MASK 0x7
#define UARTPFIFO_TXSIZE_OFF 4
#define UARTPFIFO_RXFE 0x08
#define UARTPFIFO_RXSIZE_OFF 0
#define UARTCFIFO_TXFLUSH 0x80
#define UARTCFIFO_RXFLUSH 0x40
#define UARTCFIFO_RXOFE 0x04
#define UARTCFIFO_TXOFE 0x02
#define UARTCFIFO_RXUFE 0x01
#define UARTSFIFO_TXEMPT 0x80
#define UARTSFIFO_RXEMPT 0x40
#define UARTSFIFO_RXOF 0x04
#define UARTSFIFO_TXOF 0x02
#define UARTSFIFO_RXUF 0x01
/* 32-bit global registers only for i.MX7ULP/i.MX8x
* Used to reset all internal logic and registers, except the Global Register.
*/
#define UART_GLOBAL 0x8
/* 32-bit register definition */
#define UARTBAUD 0x00
#define UARTSTAT 0x04
#define UARTCTRL 0x08
#define UARTDATA 0x0C
#define UARTMATCH 0x10
#define UARTMODIR 0x14
#define UARTFIFO 0x18
#define UARTWATER 0x1c
#define UARTBAUD_MAEN1 0x80000000
#define UARTBAUD_MAEN2 0x40000000
#define UARTBAUD_M10 0x20000000
#define UARTBAUD_TDMAE 0x00800000
#define UARTBAUD_RDMAE 0x00200000
#define UARTBAUD_RIDMAE 0x00100000
#define UARTBAUD_MATCFG 0x00400000
#define UARTBAUD_BOTHEDGE 0x00020000
#define UARTBAUD_RESYNCDIS 0x00010000
#define UARTBAUD_LBKDIE 0x00008000
#define UARTBAUD_RXEDGIE 0x00004000
#define UARTBAUD_SBNS 0x00002000
#define UARTBAUD_SBR 0x00000000
#define UARTBAUD_SBR_MASK 0x1fff
#define UARTBAUD_OSR_MASK 0x1f
#define UARTBAUD_OSR_SHIFT 24
#define UARTSTAT_LBKDIF 0x80000000
#define UARTSTAT_RXEDGIF 0x40000000
#define UARTSTAT_MSBF 0x20000000
#define UARTSTAT_RXINV 0x10000000
#define UARTSTAT_RWUID 0x08000000
#define UARTSTAT_BRK13 0x04000000
#define UARTSTAT_LBKDE 0x02000000
#define UARTSTAT_RAF 0x01000000
#define UARTSTAT_TDRE 0x00800000
#define UARTSTAT_TC 0x00400000
#define UARTSTAT_RDRF 0x00200000
#define UARTSTAT_IDLE 0x00100000
#define UARTSTAT_OR 0x00080000
#define UARTSTAT_NF 0x00040000
#define UARTSTAT_FE 0x00020000
#define UARTSTAT_PE 0x00010000
#define UARTSTAT_MA1F 0x00008000
#define UARTSTAT_M21F 0x00004000
#define UARTCTRL_R8T9 0x80000000
#define UARTCTRL_R9T8 0x40000000
#define UARTCTRL_TXDIR 0x20000000
#define UARTCTRL_TXINV 0x10000000
#define UARTCTRL_ORIE 0x08000000
#define UARTCTRL_NEIE 0x04000000
#define UARTCTRL_FEIE 0x02000000
#define UARTCTRL_PEIE 0x01000000
#define UARTCTRL_TIE 0x00800000
#define UARTCTRL_TCIE 0x00400000
#define UARTCTRL_RIE 0x00200000
#define UARTCTRL_ILIE 0x00100000
#define UARTCTRL_TE 0x00080000
#define UARTCTRL_RE 0x00040000
#define UARTCTRL_RWU 0x00020000
#define UARTCTRL_SBK 0x00010000
#define UARTCTRL_MA1IE 0x00008000
#define UARTCTRL_MA2IE 0x00004000
#define UARTCTRL_IDLECFG_OFF 0x8
#define UARTCTRL_LOOPS 0x00000080
#define UARTCTRL_DOZEEN 0x00000040
#define UARTCTRL_RSRC 0x00000020
#define UARTCTRL_M 0x00000010
#define UARTCTRL_WAKE 0x00000008
#define UARTCTRL_ILT 0x00000004
#define UARTCTRL_PE 0x00000002
#define UARTCTRL_PT 0x00000001
#define UARTDATA_NOISY 0x00008000
#define UARTDATA_PARITYE 0x00004000
#define UARTDATA_FRETSC 0x00002000
#define UARTDATA_RXEMPT 0x00001000
#define UARTDATA_IDLINE 0x00000800
#define UARTDATA_MASK 0x3ff
#define UARTMODIR_IREN 0x00020000
#define UARTMODIR_RTSWATER_S 0x8
#define UARTMODIR_TXCTSSRC 0x00000020
#define UARTMODIR_TXCTSC 0x00000010
#define UARTMODIR_RXRTSE 0x00000008
#define UARTMODIR_TXRTSPOL 0x00000004
#define UARTMODIR_TXRTSE 0x00000002
#define UARTMODIR_TXCTSE 0x00000001
#define UARTFIFO_TXEMPT 0x00800000
#define UARTFIFO_RXEMPT 0x00400000
#define UARTFIFO_TXOF 0x00020000
#define UARTFIFO_RXUF 0x00010000
#define UARTFIFO_TXFLUSH 0x00008000
#define UARTFIFO_RXFLUSH 0x00004000
#define UARTFIFO_RXIDEN_MASK 0x7
#define UARTFIFO_RXIDEN_OFF 10
#define UARTFIFO_TXOFE 0x00000200
#define UARTFIFO_RXUFE 0x00000100
#define UARTFIFO_TXFE 0x00000080
#define UARTFIFO_FIFOSIZE_MASK 0x7
#define UARTFIFO_TXSIZE_OFF 4
#define UARTFIFO_RXFE 0x00000008
#define UARTFIFO_RXSIZE_OFF 0
#define UARTFIFO_DEPTH(x) (0x1 << ((x) ? ((x) + 1) : 0))
#define UARTWATER_COUNT_MASK 0xff
#define UARTWATER_TXCNT_OFF 8
#define UARTWATER_RXCNT_OFF 24
#define UARTWATER_WATER_MASK 0xff
#define UARTWATER_TXWATER_OFF 0
#define UARTWATER_RXWATER_OFF 16
#define UART_GLOBAL_RST 0x2
#define GLOBAL_RST_MIN_US 20
#define GLOBAL_RST_MAX_US 40
#define UARTFIFO_RXIDEN_RDRF 0x3
#define UARTCTRL_IDLECFG 0x7
/* Rx DMA timeout in ms, which is used to calculate Rx ring buffer size */
#define DMA_RX_TIMEOUT (10)
#define UART_AUTOSUSPEND_TIMEOUT 3000
#define DRIVER_NAME "fsl-lpuart"
#define DEV_NAME "ttyLP"
#define UART_NR 6
/* IMX lpuart has four extra unused regs located at the beginning */
#define IMX_REG_OFF 0x10
enum lpuart_type {
VF610_LPUART,
LS1021A_LPUART,
LS1028A_LPUART,
IMX7ULP_LPUART,
IMX8ULP_LPUART,
IMX8QXP_LPUART,
};
struct lpuart_port {
struct uart_port port;
enum lpuart_type devtype;
struct clk *ipg_clk;
struct clk *baud_clk;
unsigned int txfifo_size;
unsigned int rxfifo_size;
u8 rx_watermark;
bool dma_eeop;
bool lpuart_dma_tx_use;
bool lpuart_dma_rx_use;
bool dma_rx_chan_active;
struct dma_chan *dma_tx_chan;
struct dma_chan *dma_rx_chan;
struct dma_async_tx_descriptor *dma_tx_desc;
struct dma_async_tx_descriptor *dma_rx_desc;
dma_cookie_t dma_tx_cookie;
dma_cookie_t dma_rx_cookie;
unsigned int dma_tx_bytes;
unsigned int dma_rx_bytes;
bool dma_tx_in_progress;
unsigned int dma_rx_timeout;
struct timer_list lpuart_timer;
struct scatterlist rx_sgl, tx_sgl[2];
struct circ_buf rx_ring;
int rx_dma_rng_buf_len;
int rx_dma_periods;
unsigned int dma_tx_nents;
wait_queue_head_t dma_wait;
bool is_cs7; /* Set to true when character size is 7 */
/* and the parity is enabled */
};
struct lpuart_soc_data {
enum lpuart_type devtype;
char iotype;
u8 reg_off;
u8 rx_watermark;
};
static const struct lpuart_soc_data vf_data = {
.devtype = VF610_LPUART,
.iotype = UPIO_MEM,
.rx_watermark = 1,
};
static const struct lpuart_soc_data ls1021a_data = {
.devtype = LS1021A_LPUART,
.iotype = UPIO_MEM32BE,
.rx_watermark = 0,
};
static const struct lpuart_soc_data ls1028a_data = {
.devtype = LS1028A_LPUART,
.iotype = UPIO_MEM32,
.rx_watermark = 0,
};
static struct lpuart_soc_data imx7ulp_data = {
.devtype = IMX7ULP_LPUART,
.iotype = UPIO_MEM32,
.reg_off = IMX_REG_OFF,
.rx_watermark = 0,
};
static struct lpuart_soc_data imx8ulp_data = {
.devtype = IMX8ULP_LPUART,
.iotype = UPIO_MEM32,
.reg_off = IMX_REG_OFF,
.rx_watermark = 3,
};
static struct lpuart_soc_data imx8qxp_data = {
.devtype = IMX8QXP_LPUART,
.iotype = UPIO_MEM32,
.reg_off = IMX_REG_OFF,
.rx_watermark = 31,
};
static const struct of_device_id lpuart_dt_ids[] = {
{ .compatible = "fsl,vf610-lpuart", .data = &vf_data, },
{ .compatible = "fsl,ls1021a-lpuart", .data = &ls1021a_data, },
{ .compatible = "fsl,ls1028a-lpuart", .data = &ls1028a_data, },
{ .compatible = "fsl,imx7ulp-lpuart", .data = &imx7ulp_data, },
{ .compatible = "fsl,imx8ulp-lpuart", .data = &imx8ulp_data, },
{ .compatible = "fsl,imx8qxp-lpuart", .data = &imx8qxp_data, },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, lpuart_dt_ids);
/* Forward declare this for the dma callbacks*/
static void lpuart_dma_tx_complete(void *arg);
static void lpuart_dma_rx_free(struct uart_port *port, bool dma_terminate);
static inline bool is_layerscape_lpuart(struct lpuart_port *sport)
{
return (sport->devtype == LS1021A_LPUART ||
sport->devtype == LS1028A_LPUART);
}
static inline bool is_imx7ulp_lpuart(struct lpuart_port *sport)
{
return sport->devtype == IMX7ULP_LPUART;
}
static inline bool is_imx8ulp_lpuart(struct lpuart_port *sport)
{
return sport->devtype == IMX8ULP_LPUART;
}
static inline bool is_imx8qxp_lpuart(struct lpuart_port *sport)
{
return sport->devtype == IMX8QXP_LPUART;
}
static inline u32 lpuart32_read(struct uart_port *port, u32 off)
{
switch (port->iotype) {
case UPIO_MEM32:
return readl(port->membase + off);
case UPIO_MEM32BE:
return ioread32be(port->membase + off);
default:
return 0;
}
}
static inline void lpuart32_write(struct uart_port *port, u32 val,
u32 off)
{
switch (port->iotype) {
case UPIO_MEM32:
writel(val, port->membase + off);
break;
case UPIO_MEM32BE:
iowrite32be(val, port->membase + off);
break;
}
}
static int __lpuart_enable_clks(struct lpuart_port *sport, bool is_en)
{
int ret = 0;
if (is_en) {
ret = clk_prepare_enable(sport->ipg_clk);
if (ret)
return ret;
ret = clk_prepare_enable(sport->baud_clk);
if (ret) {
clk_disable_unprepare(sport->ipg_clk);
return ret;
}
} else {
clk_disable_unprepare(sport->baud_clk);
clk_disable_unprepare(sport->ipg_clk);
}
return 0;
}
static unsigned int lpuart_get_baud_clk_rate(struct lpuart_port *sport)
{
if (is_imx8qxp_lpuart(sport))
return clk_get_rate(sport->baud_clk);
return clk_get_rate(sport->ipg_clk);
}
#define lpuart_enable_clks(x) __lpuart_enable_clks(x, true)
#define lpuart_disable_clks(x) __lpuart_enable_clks(x, false)
static int lpuart_global_reset(struct lpuart_port *sport)
{
struct uart_port *port = &sport->port;
void __iomem *global_addr;
int ret;
if (uart_console(port))
return 0;
ret = clk_prepare_enable(sport->ipg_clk);
if (ret) {
dev_err(sport->port.dev, "failed to enable uart ipg clk: %d\n", ret);
return ret;
}
if (is_imx7ulp_lpuart(sport) || is_imx8ulp_lpuart(sport) || is_imx8qxp_lpuart(sport)) {
global_addr = port->membase + UART_GLOBAL - IMX_REG_OFF;
writel(UART_GLOBAL_RST, global_addr);
usleep_range(GLOBAL_RST_MIN_US, GLOBAL_RST_MAX_US);
writel(0, global_addr);
usleep_range(GLOBAL_RST_MIN_US, GLOBAL_RST_MAX_US);
}
clk_disable_unprepare(sport->ipg_clk);
return 0;
}
static void lpuart_stop_tx(struct uart_port *port)
{
unsigned char temp;
temp = readb(port->membase + UARTCR2);
temp &= ~(UARTCR2_TIE | UARTCR2_TCIE);
writeb(temp, port->membase + UARTCR2);
}
static void lpuart32_stop_tx(struct uart_port *port)
{
unsigned long temp;
temp = lpuart32_read(port, UARTCTRL);
temp &= ~(UARTCTRL_TIE | UARTCTRL_TCIE);
lpuart32_write(port, temp, UARTCTRL);
}
static void lpuart_stop_rx(struct uart_port *port)
{
unsigned char temp;
temp = readb(port->membase + UARTCR2);
writeb(temp & ~UARTCR2_RE, port->membase + UARTCR2);
}
static void lpuart32_stop_rx(struct uart_port *port)
{
unsigned long temp;
temp = lpuart32_read(port, UARTCTRL);
lpuart32_write(port, temp & ~UARTCTRL_RE, UARTCTRL);
}
static void lpuart_dma_tx(struct lpuart_port *sport)
{
struct circ_buf *xmit = &sport->port.state->xmit;
struct scatterlist *sgl = sport->tx_sgl;
struct device *dev = sport->port.dev;
struct dma_chan *chan = sport->dma_tx_chan;
int ret;
if (sport->dma_tx_in_progress)
return;
sport->dma_tx_bytes = uart_circ_chars_pending(xmit);
if (xmit->tail < xmit->head || xmit->head == 0) {
sport->dma_tx_nents = 1;
sg_init_one(sgl, xmit->buf + xmit->tail, sport->dma_tx_bytes);
} else {
sport->dma_tx_nents = 2;
sg_init_table(sgl, 2);
sg_set_buf(sgl, xmit->buf + xmit->tail,
UART_XMIT_SIZE - xmit->tail);
sg_set_buf(sgl + 1, xmit->buf, xmit->head);
}
ret = dma_map_sg(chan->device->dev, sgl, sport->dma_tx_nents,
DMA_TO_DEVICE);
if (!ret) {
dev_err(dev, "DMA mapping error for TX.\n");
return;
}
sport->dma_tx_desc = dmaengine_prep_slave_sg(chan, sgl,
ret, DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT);
if (!sport->dma_tx_desc) {
dma_unmap_sg(chan->device->dev, sgl, sport->dma_tx_nents,
DMA_TO_DEVICE);
dev_err(dev, "Cannot prepare TX slave DMA!\n");
return;
}
sport->dma_tx_desc->callback = lpuart_dma_tx_complete;
sport->dma_tx_desc->callback_param = sport;
sport->dma_tx_in_progress = true;
sport->dma_tx_cookie = dmaengine_submit(sport->dma_tx_desc);
dma_async_issue_pending(chan);
}
static bool lpuart_stopped_or_empty(struct uart_port *port)
{
return uart_circ_empty(&port->state->xmit) || uart_tx_stopped(port);
}
static void lpuart_dma_tx_complete(void *arg)
{
struct lpuart_port *sport = arg;
struct scatterlist *sgl = &sport->tx_sgl[0];
struct circ_buf *xmit = &sport->port.state->xmit;
struct dma_chan *chan = sport->dma_tx_chan;
unsigned long flags;
spin_lock_irqsave(&sport->port.lock, flags);
if (!sport->dma_tx_in_progress) {
spin_unlock_irqrestore(&sport->port.lock, flags);
return;
}
dma_unmap_sg(chan->device->dev, sgl, sport->dma_tx_nents,
DMA_TO_DEVICE);
xmit->tail = (xmit->tail + sport->dma_tx_bytes) & (UART_XMIT_SIZE - 1);
sport->port.icount.tx += sport->dma_tx_bytes;
sport->dma_tx_in_progress = false;
spin_unlock_irqrestore(&sport->port.lock, flags);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&sport->port);
if (waitqueue_active(&sport->dma_wait)) {
wake_up(&sport->dma_wait);
return;
}
spin_lock_irqsave(&sport->port.lock, flags);
if (!lpuart_stopped_or_empty(&sport->port))
lpuart_dma_tx(sport);
spin_unlock_irqrestore(&sport->port.lock, flags);
}
static dma_addr_t lpuart_dma_datareg_addr(struct lpuart_port *sport)
{
switch (sport->port.iotype) {
case UPIO_MEM32:
return sport->port.mapbase + UARTDATA;
case UPIO_MEM32BE:
return sport->port.mapbase + UARTDATA + sizeof(u32) - 1;
}
return sport->port.mapbase + UARTDR;
}
static int lpuart_dma_tx_request(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port,
struct lpuart_port, port);
struct dma_slave_config dma_tx_sconfig = {};
int ret;
dma_tx_sconfig.dst_addr = lpuart_dma_datareg_addr(sport);
dma_tx_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
dma_tx_sconfig.dst_maxburst = 1;
dma_tx_sconfig.direction = DMA_MEM_TO_DEV;
ret = dmaengine_slave_config(sport->dma_tx_chan, &dma_tx_sconfig);
if (ret) {
dev_err(sport->port.dev,
"DMA slave config failed, err = %d\n", ret);
return ret;
}
return 0;
}
static bool lpuart_is_32(struct lpuart_port *sport)
{
return sport->port.iotype == UPIO_MEM32 ||
sport->port.iotype == UPIO_MEM32BE;
}
static void lpuart_flush_buffer(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
struct dma_chan *chan = sport->dma_tx_chan;
u32 val;
if (sport->lpuart_dma_tx_use) {
if (sport->dma_tx_in_progress) {
dma_unmap_sg(chan->device->dev, &sport->tx_sgl[0],
sport->dma_tx_nents, DMA_TO_DEVICE);
sport->dma_tx_in_progress = false;
}
dmaengine_terminate_all(chan);
}
if (lpuart_is_32(sport)) {
val = lpuart32_read(&sport->port, UARTFIFO);
val |= UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH;
lpuart32_write(&sport->port, val, UARTFIFO);
} else {
val = readb(sport->port.membase + UARTCFIFO);
val |= UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH;
writeb(val, sport->port.membase + UARTCFIFO);
}
}
static void lpuart_wait_bit_set(struct uart_port *port, unsigned int offset,
u8 bit)
{
while (!(readb(port->membase + offset) & bit))
cpu_relax();
}
static void lpuart32_wait_bit_set(struct uart_port *port, unsigned int offset,
u32 bit)
{
while (!(lpuart32_read(port, offset) & bit))
cpu_relax();
}
#if defined(CONFIG_CONSOLE_POLL)
static int lpuart_poll_init(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port,
struct lpuart_port, port);
unsigned long flags;
unsigned char temp;
sport->port.fifosize = 0;
spin_lock_irqsave(&sport->port.lock, flags);
/* Disable Rx & Tx */
writeb(0, sport->port.membase + UARTCR2);
temp = readb(sport->port.membase + UARTPFIFO);
/* Enable Rx and Tx FIFO */
writeb(temp | UARTPFIFO_RXFE | UARTPFIFO_TXFE,
sport->port.membase + UARTPFIFO);
/* flush Tx and Rx FIFO */
writeb(UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH,
sport->port.membase + UARTCFIFO);
/* explicitly clear RDRF */
if (readb(sport->port.membase + UARTSR1) & UARTSR1_RDRF) {
readb(sport->port.membase + UARTDR);
writeb(UARTSFIFO_RXUF, sport->port.membase + UARTSFIFO);
}
writeb(0, sport->port.membase + UARTTWFIFO);
writeb(1, sport->port.membase + UARTRWFIFO);
/* Enable Rx and Tx */
writeb(UARTCR2_RE | UARTCR2_TE, sport->port.membase + UARTCR2);
spin_unlock_irqrestore(&sport->port.lock, flags);
return 0;
}
static void lpuart_poll_put_char(struct uart_port *port, unsigned char c)
{
/* drain */
lpuart_wait_bit_set(port, UARTSR1, UARTSR1_TDRE);
writeb(c, port->membase + UARTDR);
}
static int lpuart_poll_get_char(struct uart_port *port)
{
if (!(readb(port->membase + UARTSR1) & UARTSR1_RDRF))
return NO_POLL_CHAR;
return readb(port->membase + UARTDR);
}
static int lpuart32_poll_init(struct uart_port *port)
{
unsigned long flags;
struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
u32 temp;
sport->port.fifosize = 0;
spin_lock_irqsave(&sport->port.lock, flags);
/* Disable Rx & Tx */
lpuart32_write(&sport->port, 0, UARTCTRL);
temp = lpuart32_read(&sport->port, UARTFIFO);
/* Enable Rx and Tx FIFO */
lpuart32_write(&sport->port, temp | UARTFIFO_RXFE | UARTFIFO_TXFE, UARTFIFO);
/* flush Tx and Rx FIFO */
lpuart32_write(&sport->port, UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH, UARTFIFO);
/* explicitly clear RDRF */
if (lpuart32_read(&sport->port, UARTSTAT) & UARTSTAT_RDRF) {
lpuart32_read(&sport->port, UARTDATA);
lpuart32_write(&sport->port, UARTFIFO_RXUF, UARTFIFO);
}
/* Enable Rx and Tx */
lpuart32_write(&sport->port, UARTCTRL_RE | UARTCTRL_TE, UARTCTRL);
spin_unlock_irqrestore(&sport->port.lock, flags);
return 0;
}
static void lpuart32_poll_put_char(struct uart_port *port, unsigned char c)
{
lpuart32_wait_bit_set(port, UARTSTAT, UARTSTAT_TDRE);
lpuart32_write(port, c, UARTDATA);
}
static int lpuart32_poll_get_char(struct uart_port *port)
{
if (!(lpuart32_read(port, UARTWATER) >> UARTWATER_RXCNT_OFF))
return NO_POLL_CHAR;
return lpuart32_read(port, UARTDATA);
}
#endif
static inline void lpuart_transmit_buffer(struct lpuart_port *sport)
{
struct circ_buf *xmit = &sport->port.state->xmit;
if (sport->port.x_char) {
writeb(sport->port.x_char, sport->port.membase + UARTDR);
sport->port.icount.tx++;
sport->port.x_char = 0;
return;
}
if (lpuart_stopped_or_empty(&sport->port)) {
lpuart_stop_tx(&sport->port);
return;
}
while (!uart_circ_empty(xmit) &&
(readb(sport->port.membase + UARTTCFIFO) < sport->txfifo_size)) {
writeb(xmit->buf[xmit->tail], sport->port.membase + UARTDR);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
sport->port.icount.tx++;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&sport->port);
if (uart_circ_empty(xmit))
lpuart_stop_tx(&sport->port);
}
static inline void lpuart32_transmit_buffer(struct lpuart_port *sport)
{
struct circ_buf *xmit = &sport->port.state->xmit;
unsigned long txcnt;
if (sport->port.x_char) {
lpuart32_write(&sport->port, sport->port.x_char, UARTDATA);
sport->port.icount.tx++;
sport->port.x_char = 0;
return;
}
if (lpuart_stopped_or_empty(&sport->port)) {
lpuart32_stop_tx(&sport->port);
return;
}
txcnt = lpuart32_read(&sport->port, UARTWATER);
txcnt = txcnt >> UARTWATER_TXCNT_OFF;
txcnt &= UARTWATER_COUNT_MASK;
while (!uart_circ_empty(xmit) && (txcnt < sport->txfifo_size)) {
lpuart32_write(&sport->port, xmit->buf[xmit->tail], UARTDATA);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
sport->port.icount.tx++;
txcnt = lpuart32_read(&sport->port, UARTWATER);
txcnt = txcnt >> UARTWATER_TXCNT_OFF;
txcnt &= UARTWATER_COUNT_MASK;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&sport->port);
if (uart_circ_empty(xmit))
lpuart32_stop_tx(&sport->port);
}
static void lpuart_start_tx(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port,
struct lpuart_port, port);
unsigned char temp;
temp = readb(port->membase + UARTCR2);
writeb(temp | UARTCR2_TIE, port->membase + UARTCR2);
if (sport->lpuart_dma_tx_use) {
if (!lpuart_stopped_or_empty(port))
lpuart_dma_tx(sport);
} else {
if (readb(port->membase + UARTSR1) & UARTSR1_TDRE)
lpuart_transmit_buffer(sport);
}
}
static void lpuart32_start_tx(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
unsigned long temp;
if (sport->lpuart_dma_tx_use) {
if (!lpuart_stopped_or_empty(port))
lpuart_dma_tx(sport);
} else {
temp = lpuart32_read(port, UARTCTRL);
lpuart32_write(port, temp | UARTCTRL_TIE, UARTCTRL);
if (lpuart32_read(port, UARTSTAT) & UARTSTAT_TDRE)
lpuart32_transmit_buffer(sport);
}
}
static void
lpuart_uart_pm(struct uart_port *port, unsigned int state, unsigned int oldstate)
{
switch (state) {
case UART_PM_STATE_OFF:
pm_runtime_mark_last_busy(port->dev);
pm_runtime_put_autosuspend(port->dev);
break;
default:
pm_runtime_get_sync(port->dev);
break;
}
}
/* return TIOCSER_TEMT when transmitter is not busy */
static unsigned int lpuart_tx_empty(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port,
struct lpuart_port, port);
unsigned char sr1 = readb(port->membase + UARTSR1);
unsigned char sfifo = readb(port->membase + UARTSFIFO);
if (sport->dma_tx_in_progress)
return 0;
if (sr1 & UARTSR1_TC && sfifo & UARTSFIFO_TXEMPT)
return TIOCSER_TEMT;
return 0;
}
static unsigned int lpuart32_tx_empty(struct uart_port *port)
{
struct lpuart_port *sport = container_of(port,
struct lpuart_port, port);
unsigned long stat = lpuart32_read(port, UARTSTAT);
unsigned long sfifo = lpuart32_read(port, UARTFIFO);
if (sport->dma_tx_in_progress)
return 0;
if (stat & UARTSTAT_TC && sfifo & UARTFIFO_TXEMPT)
return TIOCSER_TEMT;
return 0;
}
static void lpuart_txint(struct lpuart_port *sport)
{
spin_lock(&sport->port.lock);
lpuart_transmit_buffer(sport);
spin_unlock(&sport->port.lock);
}
static void lpuart_rxint(struct lpuart_port *sport)
{
unsigned int flg, ignored = 0, overrun = 0;
struct tty_port *port = &sport->port.state->port;
unsigned char rx, sr;
spin_lock(&sport->port.lock);
while (!(readb(sport->port.membase + UARTSFIFO) & UARTSFIFO_RXEMPT)) {
flg = TTY_NORMAL;
sport->port.icount.rx++;
/*
* to clear the FE, OR, NF, FE, PE flags,
* read SR1 then read DR
*/
sr = readb(sport->port.membase + UARTSR1);
rx = readb(sport->port.membase + UARTDR);
if (uart_prepare_sysrq_char(&sport->port, rx))
continue;
if (sr & (UARTSR1_PE | UARTSR1_OR | UARTSR1_FE)) {
if (sr & UARTSR1_PE)
sport->port.icount.parity++;
else if (sr & UARTSR1_FE)
sport->port.icount.frame++;
if (sr & UARTSR1_OR)
overrun++;
if (sr & sport->port.ignore_status_mask) {
if (++ignored > 100)
goto out;
continue;
}
sr &= sport->port.read_status_mask;
if (sr & UARTSR1_PE)
flg = TTY_PARITY;
else if (sr & UARTSR1_FE)
flg = TTY_FRAME;
if (sr & UARTSR1_OR)
flg = TTY_OVERRUN;
sport->port.sysrq = 0;
}
if (tty_insert_flip_char(port, rx, flg) == 0)
sport->port.icount.buf_overrun++;
}
out:
if (overrun) {
sport->port.icount.overrun += overrun;
/*
* Overruns cause FIFO pointers to become missaligned.
* Flushing the receive FIFO reinitializes the pointers.
*/
writeb(UARTCFIFO_RXFLUSH, sport->port.membase + UARTCFIFO);
writeb(UARTSFIFO_RXOF, sport->port.membase + UARTSFIFO);
}
uart_unlock_and_check_sysrq(&sport->port);
tty_flip_buffer_push(port);
}
static void lpuart32_txint(struct lpuart_port *sport)
{