[PATCH v5 10/15] OMAP2+: UART: Move errata handling from serial.c to omap-serial

[PATCH v5 10/15] OMAP2+: UART: Move errata handling from serial.c to omap-serial

[Govindraj.R]

Move the errata handling mechanism from serial.c to omap-serial file
and utilise the same func in driver file.

Errata i202, i291 are moved to be handled with omap-serial
Moving the errata macro from serial.c file to driver header file
as from on errata will be handled in driver file itself.

Corrected errata id from chapter reference 2.15 to errata id i291.

Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
---
 arch/arm/mach-omap2/serial.c                  |   78 +++++--------------------
 arch/arm/plat-omap/include/plat/omap-serial.h |    5 ++
 drivers/tty/serial/omap-serial.c              |   63 ++++++++++++++++++--
 3 files changed, 77 insertions(+), 69 deletions(-)

diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
index 43d8f0d..9fe248e 100644
--- a/arch/arm/mach-omap2/serial.c
+++ b/arch/arm/mach-omap2/serial.c
@@ -41,8 +41,6 @@
 #include "control.h"
 #include "mux.h"
 
-#define UART_ERRATA_i202_MDR1_ACCESS	(0x1 << 1)
-
 /*
  * NOTE: By default the serial timeout is disabled as it causes lost characters
  * over the serial ports. This means that the UART clocks will stay on until
@@ -53,11 +51,6 @@
 
 #define MAX_UART_HWMOD_NAME_LEN		16
 
-struct omap_uart_state {
-	int num;
-	u32 dma_enabled;
-};
-
 static u8 num_uarts;
 
 static int uart_idle_hwmod(struct omap_device *od)
@@ -84,63 +77,6 @@ static struct omap_device_pm_latency omap_uart_latency[] = {
 
 #if defined(CONFIG_PM)
 
-/*
- * Work Around for Errata i202 (3430 - 1.12, 3630 - 1.6)
- * The access to uart register after MDR1 Access
- * causes UART to corrupt data.
- *
- * Need a delay =
- * 5 L4 clock cycles + 5 UART functional clock cycle (@48MHz = ~0.2uS)
- * give 10 times as much
- */
-static void omap_uart_mdr1_errataset(struct omap_uart_state *uart, u8 mdr1_val,
-		u8 fcr_val)
-{
-	u8 timeout = 255;
-
-	serial_write_reg(uart, UART_OMAP_MDR1, mdr1_val);
-	udelay(2);
-	serial_write_reg(uart, UART_FCR, fcr_val | UART_FCR_CLEAR_XMIT |
-			UART_FCR_CLEAR_RCVR);
-	/*
-	 * Wait for FIFO to empty: when empty, RX_FIFO_E bit is 0 and
-	 * TX_FIFO_E bit is 1.
-	 */
-	while (UART_LSR_THRE != (serial_read_reg(uart, UART_LSR) &
-				(UART_LSR_THRE | UART_LSR_DR))) {
-		timeout--;
-		if (!timeout) {
-			/* Should *never* happen. we warn and carry on */
-			dev_crit(&uart->pdev->dev, "Errata i202: timedout %x\n",
-			serial_read_reg(uart, UART_LSR));
-			break;
-		}
-		udelay(1);
-	}
-}
-#endif /* CONFIG_PM && CONFIG_ARCH_OMAP3 */
-
-static void omap_uart_smart_idle_enable(struct omap_uart_state *uart,
-					       int enable)
-{
-	u8 idlemode;
-
-	if (enable) {
-		/**
-		 * Errata 2.15: [UART]:Cannot Acknowledge Idle Requests
-		 * in Smartidle Mode When Configured for DMA Operations.
-		 */
-		if (uart->dma_enabled)
-			idlemode = HWMOD_IDLEMODE_FORCE;
-		else
-			idlemode = HWMOD_IDLEMODE_SMART;
-	} else {
-		idlemode = HWMOD_IDLEMODE_NO;
-	}
-
-	omap_hwmod_set_slave_idlemode(uart->oh, idlemode);
-}
-
 #ifdef CONFIG_OMAP_MUX
 static struct omap_device_pad default_uart1_pads[] __initdata = {
 	{
@@ -282,7 +218,20 @@ static void omap_uart_enable_wakeup(struct platform_device *pdev, bool enable)
 		omap_hwmod_disable_wakeup(od->hwmods[0]);
 }
 
+/*
+ * Errata i291: [UART]:Cannot Acknowledge Idle Requests
+ * in Smartidle Mode When Configured for DMA Operations.
+ * WA: configure uart in force idle mode.
+ */
+static void omap_uart_set_forceidle(struct platform_device *pdev)
+{
+	struct omap_device *od = to_omap_device(pdev);
+
+	omap_hwmod_set_slave_idlemode(od->hwmods[0], HWMOD_IDLEMODE_FORCE);
+}
+
 #else
+static void omap_uart_set_forceidle(struct platform_device *pdev) {}
 static void omap_uart_enable_wakeup(struct platform_device *pdev, bool enable)
 {}
 #endif /* CONFIG_PM */
@@ -369,6 +318,7 @@ void __init omap_serial_init_port(struct omap_board_data *bdata)
 	pdata->flags = UPF_BOOT_AUTOCONF;
 	pdata->enable_wakeup = omap_uart_enable_wakeup;
 	pdata->get_context_loss_count = omap_pm_get_dev_context_loss_count;
+	pdata->set_force_idle = omap_uart_set_forceidle;
 
 	/* Enable the MDR1 errata for OMAP3 */
 	if (cpu_is_omap34xx() && !cpu_is_ti816x())
diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h b/arch/arm/plat-omap/include/plat/omap-serial.h
index 8ef81ce..12f5262 100644
--- a/arch/arm/plat-omap/include/plat/omap-serial.h
+++ b/arch/arm/plat-omap/include/plat/omap-serial.h
@@ -56,6 +56,8 @@
 
 #define MSR_SAVE_FLAGS		UART_MSR_ANY_DELTA
 
+#define UART_ERRATA_i202_MDR1_ACCESS	(0x1 << 1)
+
 struct omap_uart_port_info {
 	bool			dma_enabled;	/* To specify DMA Mode */
 	unsigned int		uartclk;	/* UART clock rate */
@@ -65,6 +67,7 @@ struct omap_uart_port_info {
 
 	void (*enable_wakeup)(struct platform_device *, bool);
 	u32 (*get_context_loss_count)(struct device *);
+	void (*set_force_idle)(struct platform_device *);
 };
 
 struct uart_omap_dma {
@@ -118,6 +121,8 @@ struct uart_omap_port {
 	unsigned long		port_activity;
 	u32			context_loss_cnt;
 	u8			wakeups_enabled;
+	u32			errata;
+
 };
 
 #endif /* __OMAP_SERIAL_H__ */
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 43c33da..817443e 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -51,6 +51,7 @@ static struct uart_omap_port *ui[OMAP_MAX_HSUART_PORTS];
 static void uart_tx_dma_callback(int lch, u16 ch_status, void *data);
 static void serial_omap_rx_timeout(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 inline unsigned int serial_in(struct uart_omap_port *up, int offset)
 {
@@ -805,7 +806,11 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	/* Protocol, Baud Rate, and Interrupt Settings */
 
-	serial_out(up, UART_OMAP_MDR1, up->mdr1);
+	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
+		serial_omap_mdr1_errataset(up, up->mdr1);
+	else
+		serial_out(up, UART_OMAP_MDR1, up->mdr1);
+
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 
 	up->efr = serial_in(up, UART_EFR);
@@ -830,7 +835,10 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 	else
 		up->mdr1 = UART_OMAP_MDR1_16X_MODE;
 
-	serial_out(up, UART_OMAP_MDR1, up->mdr1);
+	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
+		serial_omap_mdr1_errataset(up, up->mdr1);
+	else
+		serial_out(up, UART_OMAP_MDR1, up->mdr1);
 
 	/* Hardware Flow Control Configuration */
 
@@ -1350,6 +1358,7 @@ static int serial_omap_probe(struct platform_device *pdev)
 	up->port.flags = omap_up_info->flags;
 	up->port.uartclk = omap_up_info->uartclk;
 	up->uart_dma.uart_base = mem->start;
+	up->errata = omap_up_info->errata;
 
 	if (omap_up_info->dma_enabled) {
 		up->uart_dma.uart_dma_tx = dma_tx->start;
@@ -1405,9 +1414,47 @@ static int serial_omap_remove(struct platform_device *dev)
 	return 0;
 }
 
+/*
+ * Work Around for Errata i202 (3430 - 1.12, 3630 - 1.6)
+ * The access to uart register after MDR1 Access
+ * causes UART to corrupt data.
+ *
+ * Need a delay =
+ * 5 L4 clock cycles + 5 UART functional clock cycle (@48MHz = ~0.2uS)
+ * give 10 times as much
+ */
+static void serial_omap_mdr1_errataset(struct uart_omap_port *up, u8 mdr1)
+{
+	u8 timeout = 255;
+
+	serial_out(up, UART_OMAP_MDR1, mdr1);
+	udelay(2);
+	serial_out(up, UART_FCR, up->fcr | UART_FCR_CLEAR_XMIT |
+			UART_FCR_CLEAR_RCVR);
+	/*
+	 * Wait for FIFO to empty: when empty, RX_FIFO_E bit is 0 and
+	 * TX_FIFO_E bit is 1.
+	 */
+	while (UART_LSR_THRE != (serial_in(up, UART_LSR) &
+				(UART_LSR_THRE | UART_LSR_DR))) {
+		timeout--;
+		if (!timeout) {
+			/* Should *never* happen. we warn and carry on */
+			dev_crit(&up->pdev->dev, "Errata i202: timedout %x\n",
+						serial_in(up, UART_LSR));
+			break;
+		}
+		udelay(1);
+	}
+}
+
 static void serial_omap_restore_context(struct uart_omap_port *up)
 {
-	serial_out(up, UART_OMAP_MDR1, up->mdr1);
+	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
+		serial_omap_mdr1_errataset(up, UART_OMAP_MDR1_DISABLE);
+	else
+		serial_out(up, UART_OMAP_MDR1, UART_OMAP_MDR1_DISABLE);
+
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
 	serial_out(up, UART_EFR, UART_EFR_ECB);
 	serial_out(up, UART_LCR, 0x0); /* Operational mode */
@@ -1423,8 +1470,10 @@ static void serial_omap_restore_context(struct uart_omap_port *up)
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
 	serial_out(up, UART_EFR, up->efr);
 	serial_out(up, UART_LCR, up->lcr);
-	/* UART 16x mode */
-	serial_out(up, UART_OMAP_MDR1, up->mdr1);
+	if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
+		serial_omap_mdr1_errataset(up, up->mdr1);
+	else
+		serial_out(up, UART_OMAP_MDR1, up->mdr1);
 }
 
 static int serial_omap_runtime_suspend(struct device *dev)
@@ -1453,6 +1502,10 @@ static int serial_omap_runtime_suspend(struct device *dev)
 		}
 	}
 
+	/* Errata i291 */
+	if (up->use_dma && pdata->set_force_idle)
+		pdata->set_force_idle(up->pdev);
+
 	return 0;
 }
 
-- 
1.7.4.1

[PATCH v5 11/15] OMAP2+: UART: Allow UART parameters to be configured from board file.

[Govindraj.R]

From: Deepak K <deepak.k@ti.com>

The following UART parameters are defined within the UART driver:

1). Whether the UART uses DMA (dma_enabled), by default set to 0
2). The size of dma buffer (set to 4096 bytes)
3). The time after which the dma should stop if no more data is received.
4). The auto suspend delay that will be passed for pm_runtime_autosuspend
    where uart will be disabled after timeout

Different UARTs may be used for different purpose such as the console,
for interfacing bluetooth chip, for interfacing to a modem chip, etc.
Therefore, it is necessary to be able to customize the above settings
for a given board on a per UART basis.

This change allows these parameters to be configured from the board file
and allows the parameters to be configured for each UART independently.

If a board does not define its own custom parameters for the UARTs, then
use the default parameters in the structure "omap_serial_default_info".
The default parameters are defined to be the same as the current settings
in the UART driver to avoid breaking the UART for any cuurnelty supported
boards. By default, make all boards use the default UART parameters.

Signed-off-by: Deepak K <deepak.k@ti.com>
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
---
This patch is derived and reworked from a custom 2.6.35 kernel
Available here:
http://git.omapzoom.org/?p=kernel/omap.git;
a=commitdiff;h=584ef316542f77312be7ba96a0f3013c8f64852b;
hp=7233a76cb362c0fc603f773274159adff91d3513

 arch/arm/mach-omap2/board-4430sdp.c           |    8 ++--
 arch/arm/mach-omap2/board-n8x0.c              |    6 +-
 arch/arm/mach-omap2/board-omap4panda.c        |    8 ++--
 arch/arm/mach-omap2/serial.c                  |   56 ++++++++++++++++++++----
 arch/arm/plat-omap/include/plat/omap-serial.h |    7 ++-
 arch/arm/plat-omap/include/plat/serial.h      |    6 ++-
 drivers/tty/serial/omap-serial.c              |    8 +--
 7 files changed, 69 insertions(+), 30 deletions(-)

diff --git a/arch/arm/mach-omap2/board-4430sdp.c b/arch/arm/mach-omap2/board-4430sdp.c
index c7cef44..41b43cb 100644
--- a/arch/arm/mach-omap2/board-4430sdp.c
+++ b/arch/arm/mach-omap2/board-4430sdp.c
@@ -743,11 +743,11 @@ static inline void board_serial_init(void)
 	bdata.pads_cnt	= 0;
 	bdata.id	= 0;
 	/* pass dummy data for UART1 */
-	omap_serial_init_port(&bdata);
+	omap_serial_init_port(&bdata, NULL);
 
-	omap_serial_init_port(&serial2_data);
-	omap_serial_init_port(&serial3_data);
-	omap_serial_init_port(&serial4_data);
+	omap_serial_init_port(&serial2_data, NULL);
+	omap_serial_init_port(&serial3_data, NULL);
+	omap_serial_init_port(&serial4_data, NULL);
 }
 #else
 #define board_mux	NULL
diff --git a/arch/arm/mach-omap2/board-n8x0.c b/arch/arm/mach-omap2/board-n8x0.c
index e11f0c5..3408726 100644
--- a/arch/arm/mach-omap2/board-n8x0.c
+++ b/arch/arm/mach-omap2/board-n8x0.c
@@ -656,15 +656,15 @@ static inline void board_serial_init(void)
 	bdata.pads_cnt = 0;
 
 	bdata.id = 0;
-	omap_serial_init_port(&bdata);
+	omap_serial_init_port(&bdata, NULL);
 
 	bdata.id = 1;
-	omap_serial_init_port(&bdata);
+	omap_serial_init_port(&bdata, NULL);
 
 	bdata.id = 2;
 	bdata.pads = serial2_pads;
 	bdata.pads_cnt = ARRAY_SIZE(serial2_pads);
-	omap_serial_init_port(&bdata);
+	omap_serial_init_port(&bdata, NULL);
 }
 
 #else
diff --git a/arch/arm/mach-omap2/board-omap4panda.c b/arch/arm/mach-omap2/board-omap4panda.c
index 9aaa960..fdfac0c 100644
--- a/arch/arm/mach-omap2/board-omap4panda.c
+++ b/arch/arm/mach-omap2/board-omap4panda.c
@@ -425,11 +425,11 @@ static inline void board_serial_init(void)
 	bdata.pads_cnt  = 0;
 	bdata.id        = 0;
 	/* pass dummy data for UART1 */
-	omap_serial_init_port(&bdata);
+	omap_serial_init_port(&bdata, NULL);
 
-	omap_serial_init_port(&serial2_data);
-	omap_serial_init_port(&serial3_data);
-	omap_serial_init_port(&serial4_data);
+	omap_serial_init_port(&serial2_data, NULL);
+	omap_serial_init_port(&serial3_data, NULL);
+	omap_serial_init_port(&serial4_data, NULL);
 }
 #else
 #define board_mux	NULL
diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
index 9fe248e..0e45d9a 100644
--- a/arch/arm/mach-omap2/serial.c
+++ b/arch/arm/mach-omap2/serial.c
@@ -42,17 +42,29 @@
 #include "mux.h"
 
 /*
- * NOTE: By default the serial timeout is disabled as it causes lost characters
- * over the serial ports. This means that the UART clocks will stay on until
- * disabled via sysfs. This also causes that any deeper omap sleep states are
- * blocked. 
+ * NOTE: By default the serial auto_suspend timeout is disabled as it causes
+ * lost characters over the serial ports. This means that the UART clocks will
+ * stay on until power/autosuspend_delay is set for the uart from sysfs.
+ * This also causes that any deeper omap sleep states are blocked.
  */
-#define DEFAULT_TIMEOUT 0
+#define DEFAULT_AUTOSUSPEND_DELAY	-1
 
 #define MAX_UART_HWMOD_NAME_LEN		16
 
 static u8 num_uarts;
 
+#define DEFAULT_RXDMA_TIMEOUT		1	/* RX DMA polling rate (us) */
+#define DEFAULT_RXDMA_BUFSIZE		4096	/* RX DMA buffer size */
+
+static struct omap_uart_port_info omap_serial_default_info[] = {
+	{
+		.dma_enabled	= 0,
+		.dma_rx_buf_size = DEFAULT_RXDMA_BUFSIZE,
+		.dma_rx_timeout = DEFAULT_RXDMA_TIMEOUT,
+		.autosuspend_timeout = DEFAULT_AUTOSUSPEND_DELAY,
+	},
+};
+
 static int uart_idle_hwmod(struct omap_device *od)
 {
 	omap_hwmod_idle(od->hwmods[0]);
@@ -279,6 +291,7 @@ core_initcall(omap_serial_early_init);
 /**
  * omap_serial_init_port() - initialize single serial port
  * @bdata: port specific board data pointer
+ * @info: platform specific data pointer
  *
  * This function initialies serial driver for given port only.
  * Platforms can call this function instead of omap_serial_init()
@@ -287,7 +300,8 @@ core_initcall(omap_serial_early_init);
  * Don't mix calls to omap_serial_init_port() and omap_serial_init(),
  * use only one of the two.
  */
-void __init omap_serial_init_port(struct omap_board_data *bdata)
+void __init omap_serial_init_port(struct omap_board_data *bdata,
+			struct omap_uart_port_info *info)
 {
 	struct omap_hwmod *oh;
 	struct platform_device *pdev;
@@ -306,6 +320,9 @@ void __init omap_serial_init_port(struct omap_board_data *bdata)
 	if (!oh)
 		return;
 
+	if (info == NULL)
+		info = omap_serial_default_info;
+
 	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 	if (!pdata) {
 		pr_err("Memory allocation for UART pdata failed\n");
@@ -319,6 +336,10 @@ void __init omap_serial_init_port(struct omap_board_data *bdata)
 	pdata->enable_wakeup = omap_uart_enable_wakeup;
 	pdata->get_context_loss_count = omap_pm_get_dev_context_loss_count;
 	pdata->set_force_idle = omap_uart_set_forceidle;
+	pdata->dma_enabled = info->dma_enabled;
+	pdata->dma_rx_buf_size = info->dma_rx_buf_size;
+	pdata->dma_rx_timeout = info->dma_rx_timeout;
+	pdata->autosuspend_timeout = info->autosuspend_timeout;
 
 	/* Enable the MDR1 errata for OMAP3 */
 	if (cpu_is_omap34xx() && !cpu_is_ti816x())
@@ -352,13 +373,14 @@ void __init omap_serial_init_port(struct omap_board_data *bdata)
 }
 
 /**
- * omap_serial_init() - initialize all supported serial ports
+ * omap_serial_board_init() - initialize all supported serial ports
+ * @info: platform specific data pointer
  *
  * Initializes all available UARTs as serial ports. Platforms
  * can call this function when they want to have default behaviour
  * for serial ports (e.g initialize them all as serial ports).
  */
-void __init omap_serial_init(void)
+void __init omap_serial_board_init(struct omap_uart_port_info *info)
 {
 	struct omap_board_data bdata;
 	u8 i;
@@ -372,7 +394,21 @@ void __init omap_serial_init(void)
 		if (cpu_is_omap44xx() || cpu_is_omap34xx())
 			omap_serial_fill_default_pads(&bdata);
 
-		omap_serial_init_port(&bdata);
-
+		if (info == NULL)
+			omap_serial_init_port(&bdata, NULL);
+		else
+			omap_serial_init_port(&bdata, &info[i]);
 	}
 }
+
+/**
+ * omap_serial_init() - initialize all supported serial ports
+ *
+ * Initializes all available UARTs.
+ * Platforms can call this function when they want to have default behaviour
+ * for serial ports (e.g initialize them all as serial ports).
+ */
+void __init omap_serial_init(void)
+{
+	omap_serial_board_init(NULL);
+}
diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h b/arch/arm/plat-omap/include/plat/omap-serial.h
index 12f5262..a40a41a 100644
--- a/arch/arm/plat-omap/include/plat/omap-serial.h
+++ b/arch/arm/plat-omap/include/plat/omap-serial.h
@@ -64,6 +64,9 @@ struct omap_uart_port_info {
 	upf_t			flags;		/* UPF_* flags */
 
 	u32			errata;
+	unsigned int		dma_rx_buf_size;
+	unsigned int		dma_rx_timeout;
+	unsigned int		autosuspend_timeout;
 
 	void (*enable_wakeup)(struct platform_device *, bool);
 	u32 (*get_context_loss_count)(struct device *);
@@ -91,8 +94,8 @@ struct uart_omap_dma {
 	spinlock_t		rx_lock;
 	/* timer to poll activity on rx dma */
 	struct timer_list	rx_timer;
-	int			rx_buf_size;
-	int			rx_timeout;
+	unsigned int		rx_buf_size;
+	unsigned int		rx_timeout;
 };
 
 struct uart_omap_port {
diff --git a/arch/arm/plat-omap/include/plat/serial.h b/arch/arm/plat-omap/include/plat/serial.h
index b8d9303..e25534e 100644
--- a/arch/arm/plat-omap/include/plat/serial.h
+++ b/arch/arm/plat-omap/include/plat/serial.h
@@ -106,10 +106,12 @@
 #ifndef __ASSEMBLER__
 
 struct omap_board_data;
+struct omap_uart_port_info;
 
 extern void omap_serial_init(void);
-extern void omap_serial_init_port(struct omap_board_data *bdata);
-extern void omap_uart_check_wakeup(void);
+extern void omap_serial_board_init(struct omap_uart_port_info *platform_data);
+extern void omap_serial_init_port(struct omap_board_data *bdata,
+		struct omap_uart_port_info *platform_data);
 #endif
 
 #endif
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 817443e..15e0655 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -43,8 +43,6 @@
 #include <plat/dmtimer.h>
 #include <plat/omap-serial.h>
 
-#define OMAP_UART_AUTOSUSPEND_DELAY -1
-
 static struct uart_omap_port *ui[OMAP_MAX_HSUART_PORTS];
 
 /* Forward declaration of functions */
@@ -1364,8 +1362,8 @@ static int serial_omap_probe(struct platform_device *pdev)
 		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 = 4096;
-		up->uart_dma.rx_timeout = 2;
+		up->uart_dma.rx_buf_size = omap_up_info->dma_rx_buf_size;
+		up->uart_dma.rx_timeout = omap_up_info->dma_rx_timeout;
 		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;
@@ -1374,7 +1372,7 @@ static int serial_omap_probe(struct platform_device *pdev)
 
 	pm_runtime_use_autosuspend(&pdev->dev);
 	pm_runtime_set_autosuspend_delay(&pdev->dev,
-			OMAP_UART_AUTOSUSPEND_DELAY);
+			omap_up_info->autosuspend_timeout);
 
 	pm_runtime_irq_safe(&pdev->dev);
 	if (device_may_wakeup(&pdev->dev)) {
-- 
1.7.4.1

[PATCH v5 12/15] OMAP2+: UART: Make the RX_TIMEOUT for DMA configurable for each UART

[Govindraj.R]

From: Jon Hunter <jon-hunter@ti.com>

When using DMA there are two timeouts defined. The first timeout,
rx_timeout, is really a polling rate in which software polls the
DMA status to see if the DMA has finished. This is necessary for
the RX side because we do not know how much data we will receive.
The secound timeout, RX_TIMEOUT, is a timeout after which the
DMA will be stopped if no more data is received. To make this
clearer, rename rx_timeout as rx_poll_rate and rename the
function serial_omap_rx_timeout() to serial_omap_rxdma_poll().

The OMAP-Serial driver defines an RX_TIMEOUT of 3 seconds that is
used to indicate when the DMA for UART can be stopped if no more
data is received. The value is a global definition that is applied
to all instances of the UART.

Each UART may be used for a different purpose and so the timeout
required may differ. Make this value configurable for each UART so
that this value can be optimised for power savings.

Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
---
This patch is derived from a custom 2.6.35 kernel
Available here:
http://git.omapzoom.org/?p=kernel/omap.git;a=commitdiff;
h=b47839fb84e68333ea29a327cf5aa694b71be7d6;
hp=f62f570e8580507be48ad004defc2ec714b6e05d

 arch/arm/mach-omap2/serial.c                  |    5 ++++-
 arch/arm/plat-omap/include/plat/omap-serial.h |    3 ++-
 drivers/tty/serial/omap-serial.c              |   15 ++++++++-------
 3 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
index 0e45d9a..57d063a 100644
--- a/arch/arm/mach-omap2/serial.c
+++ b/arch/arm/mach-omap2/serial.c
@@ -53,13 +53,15 @@
 
 static u8 num_uarts;
 
-#define DEFAULT_RXDMA_TIMEOUT		1	/* RX DMA polling rate (us) */
+#define DEFAULT_RXDMA_POLLRATE		1	/* RX DMA polling rate (us) */
 #define DEFAULT_RXDMA_BUFSIZE		4096	/* RX DMA buffer size */
+#define DEFAULT_RXDMA_TIMEOUT		(3 * HZ)/* RX DMA timeout (jiffies) */
 
 static struct omap_uart_port_info omap_serial_default_info[] = {
 	{
 		.dma_enabled	= 0,
 		.dma_rx_buf_size = DEFAULT_RXDMA_BUFSIZE,
+		.dma_rx_poll_rate = DEFAULT_RXDMA_POLLRATE,
 		.dma_rx_timeout = DEFAULT_RXDMA_TIMEOUT,
 		.autosuspend_timeout = DEFAULT_AUTOSUSPEND_DELAY,
 	},
@@ -338,6 +340,7 @@ void __init omap_serial_init_port(struct omap_board_data *bdata,
 	pdata->set_force_idle = omap_uart_set_forceidle;
 	pdata->dma_enabled = info->dma_enabled;
 	pdata->dma_rx_buf_size = info->dma_rx_buf_size;
+	pdata->dma_rx_poll_rate = info->dma_rx_poll_rate;
 	pdata->dma_rx_timeout = info->dma_rx_timeout;
 	pdata->autosuspend_timeout = info->autosuspend_timeout;
 
diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h b/arch/arm/plat-omap/include/plat/omap-serial.h
index a40a41a..28abc6b 100644
--- a/arch/arm/plat-omap/include/plat/omap-serial.h
+++ b/arch/arm/plat-omap/include/plat/omap-serial.h
@@ -51,7 +51,6 @@
 
 #define OMAP_UART_DMA_CH_FREE	-1
 
-#define RX_TIMEOUT		(3 * HZ)
 #define OMAP_MAX_HSUART_PORTS	4
 
 #define MSR_SAVE_FLAGS		UART_MSR_ANY_DELTA
@@ -67,6 +66,7 @@ struct omap_uart_port_info {
 	unsigned int		dma_rx_buf_size;
 	unsigned int		dma_rx_timeout;
 	unsigned int		autosuspend_timeout;
+	unsigned int		dma_rx_poll_rate;
 
 	void (*enable_wakeup)(struct platform_device *, bool);
 	u32 (*get_context_loss_count)(struct device *);
@@ -95,6 +95,7 @@ struct uart_omap_dma {
 	/* timer to poll activity on rx dma */
 	struct timer_list	rx_timer;
 	unsigned int		rx_buf_size;
+	unsigned int		rx_poll_rate;
 	unsigned int		rx_timeout;
 };
 
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 15e0655..64e4ab5 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -47,7 +47,7 @@ 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_rx_timeout(unsigned long uart_no);
+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);
 
@@ -542,7 +542,7 @@ static int serial_omap_startup(struct uart_port *port)
 			(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_rx_timeout;
+		up->uart_dma.rx_timer.function = serial_omap_rxdma_poll;
 		up->uart_dma.rx_timer.data = up->pdev->id;
 		/* Currently the buffer size is 4KB. Can increase it */
 		up->uart_dma.rx_buf = dma_alloc_coherent(NULL,
@@ -1147,7 +1147,7 @@ static int serial_omap_resume(struct device *dev)
 	return 0;
 }
 
-static void serial_omap_rx_timeout(unsigned long uart_no)
+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;
@@ -1157,9 +1157,9 @@ static void serial_omap_rx_timeout(unsigned long uart_no)
 	if ((curr_dma_pos == up->uart_dma.prev_rx_dma_pos) ||
 			     (curr_dma_pos == 0)) {
 		if (jiffies_to_msecs(jiffies - up->port_activity) <
-							RX_TIMEOUT) {
+						up->uart_dma.rx_timeout) {
 			mod_timer(&up->uart_dma.rx_timer, jiffies +
-				usecs_to_jiffies(up->uart_dma.rx_timeout));
+				usecs_to_jiffies(up->uart_dma.rx_poll_rate));
 		} else {
 			serial_omap_stop_rxdma(up);
 			up->ier |= (UART_IER_RDI | UART_IER_RLSI);
@@ -1188,7 +1188,7 @@ static void serial_omap_rx_timeout(unsigned long uart_no)
 		}
 	} else  {
 		mod_timer(&up->uart_dma.rx_timer, jiffies +
-			usecs_to_jiffies(up->uart_dma.rx_timeout));
+			usecs_to_jiffies(up->uart_dma.rx_poll_rate));
 	}
 	up->port_activity = jiffies;
 }
@@ -1227,7 +1227,7 @@ static int serial_omap_start_rxdma(struct uart_omap_port *up)
 	/* 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_timeout));
+				usecs_to_jiffies(up->uart_dma.rx_poll_rate));
 	up->uart_dma.rx_dma_used = true;
 	return ret;
 }
@@ -1364,6 +1364,7 @@ static int serial_omap_probe(struct platform_device *pdev)
 		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;
-- 
1.7.4.1

[PATCH v5 13/15] OMAP2+: UART: Take console_lock in suspend path if not taken

[Govindraj.R]

In suspend path the console_lock is taken by uart_port_suspend
however when no_console_suspend is used console_lock is not taken.

During system wide suspend omap_pwr_domain hooks cut all
clocks that are left enabled. So its unsafe to proceed printing after
clocks are cut by pwr_domain hooks. Also pm_runtime will be disabled after
dpm_suspend devices happens. So buffer all prints in suspend path by taking
console_lock and print them back safely after power domain hooks re-enable
clocks back.

Use CONFIG_SERIAL_OMAP_CONSOLE macro check to take console_lock since
console ops are available only if omap console is defined.
omap-serial can be built as module without console support.

Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
---
 arch/arm/plat-omap/include/plat/omap-serial.h |    1 +
 drivers/tty/serial/omap-serial.c              |   20 ++++++++++++++++++--
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h b/arch/arm/plat-omap/include/plat/omap-serial.h
index 28abc6b..de8de87 100644
--- a/arch/arm/plat-omap/include/plat/omap-serial.h
+++ b/arch/arm/plat-omap/include/plat/omap-serial.h
@@ -126,6 +126,7 @@ struct uart_omap_port {
 	u32			context_loss_cnt;
 	u8			wakeups_enabled;
 	u32			errata;
+	u8			console_locked;
 
 };
 
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 64e4ab5..92a1f10 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1133,8 +1133,15 @@ static int serial_omap_suspend(struct device *dev)
 {
 	struct uart_omap_port *up = dev_get_drvdata(dev);
 
-	if (up)
+	if (up) {
 		uart_suspend_port(&serial_omap_reg, &up->port);
+#ifdef CONFIG_SERIAL_OMAP_CONSOLE
+		if (up->port.line == up->port.cons->index &&
+				!is_console_locked())
+			up->console_locked = console_trylock();
+#endif
+	}
+
 	return 0;
 }
 
@@ -1142,8 +1149,17 @@ static int serial_omap_resume(struct device *dev)
 {
 	struct uart_omap_port *up = dev_get_drvdata(dev);
 
-	if (up)
+	if (up) {
 		uart_resume_port(&serial_omap_reg, &up->port);
+#ifdef CONFIG_SERIAL_OMAP_CONSOLE
+		if (up->port.line == up->port.cons->index &&
+					up->console_locked) {
+			console_unlock();
+			up->console_locked = 0;
+		}
+#endif
+	}
+
 	return 0;
 }
 
-- 
1.7.4.1

[PATCH v5 14/15] OMAP2+: UART: Enable back uart clocks with runtime API for early console

[Govindraj.R]

For the early console probing we had avoided hwmod reset and idling
and uart was idled using hwmod API and enabled back using omap_device API
after omap_device registration.

Now since we are using runtime API's to enable back uart move hwmod idling and
use runtime API to enable back UART.

Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
---
 arch/arm/mach-omap2/serial.c                  |   26 ++++++++----------------
 arch/arm/plat-omap/include/plat/omap-serial.h |    1 +
 drivers/tty/serial/omap-serial.c              |    1 +
 3 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
index 57d063a..87696bf 100644
--- a/arch/arm/mach-omap2/serial.c
+++ b/arch/arm/mach-omap2/serial.c
@@ -24,13 +24,11 @@
 #include <linux/delay.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
-#include <linux/console.h>
 
 #include <plat/omap-serial.h>
 #include <plat/common.h>
 #include <plat/board.h>
 #include <plat/dma.h>
-#include <plat/omap_hwmod.h>
 #include <plat/omap_device.h>
 #include <plat/omap-pm.h>
 
@@ -244,10 +242,16 @@ static void omap_uart_set_forceidle(struct platform_device *pdev)
 	omap_hwmod_set_slave_idlemode(od->hwmods[0], HWMOD_IDLEMODE_FORCE);
 }
 
+static void omap_uart_hwmod_idle(struct platform_device *pdev)
+{
+	struct omap_device *od = to_omap_device(pdev);
+
+	omap_hwmod_idle(od->hwmods[0]);
+}
+
 #else
 static void omap_uart_set_forceidle(struct platform_device *pdev) {}
-static void omap_uart_enable_wakeup(struct platform_device *pdev, bool enable)
-{}
+static void omap_uart_hwmod_idle(struct platform_device *pdev) {}
 #endif /* CONFIG_PM */
 
 struct omap_hwmod *omap_uart_hwmod_lookup(int num)
@@ -338,6 +342,7 @@ void __init omap_serial_init_port(struct omap_board_data *bdata,
 	pdata->enable_wakeup = omap_uart_enable_wakeup;
 	pdata->get_context_loss_count = omap_pm_get_dev_context_loss_count;
 	pdata->set_force_idle = omap_uart_set_forceidle;
+	pdata->hwmod_idle = omap_uart_hwmod_idle;
 	pdata->dma_enabled = info->dma_enabled;
 	pdata->dma_rx_buf_size = info->dma_rx_buf_size;
 	pdata->dma_rx_poll_rate = info->dma_rx_poll_rate;
@@ -356,19 +361,6 @@ void __init omap_serial_init_port(struct omap_board_data *bdata,
 
 	oh->mux = omap_hwmod_mux_init(bdata->pads, bdata->pads_cnt);
 
-	console_lock(); /* in case the earlycon is on the UART */
-
-	/*
-	 * Because of early UART probing, UART did not get idled
-	 * on init.  Now that omap_device is ready, ensure full idle
-	 * before doing omap_device_enable().
-	 */
-	omap_hwmod_idle(oh);
-
-	omap_device_enable(pdev);
-
-	console_unlock();
-
 	if ((cpu_is_omap34xx() && bdata->pads))
 		device_init_wakeup(&pdev->dev, true);
 
diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h b/arch/arm/plat-omap/include/plat/omap-serial.h
index de8de87..800f215 100644
--- a/arch/arm/plat-omap/include/plat/omap-serial.h
+++ b/arch/arm/plat-omap/include/plat/omap-serial.h
@@ -71,6 +71,7 @@ struct omap_uart_port_info {
 	void (*enable_wakeup)(struct platform_device *, bool);
 	u32 (*get_context_loss_count)(struct device *);
 	void (*set_force_idle)(struct platform_device *);
+	void (*hwmod_idle)(struct platform_device *);
 };
 
 struct uart_omap_dma {
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 92a1f10..8125a89 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1394,6 +1394,7 @@ static int serial_omap_probe(struct platform_device *pdev)
 	pm_runtime_irq_safe(&pdev->dev);
 	if (device_may_wakeup(&pdev->dev)) {
 		pm_runtime_enable(&pdev->dev);
+		omap_up_info->hwmod_idle(pdev);
 		pm_runtime_get_sync(&pdev->dev);
 	}
 
-- 
1.7.4.1

[PATCH v5 15/15] OMAP2+: UART: Do not gate uart clocks if used for debug_prints

[Govindraj.R]

If OMAP UART is used as console uart and debug is enabled,
avoid gating of uart clocks to print all debug prints.

If uart clocks are gated then the debug prints from omap_device
framework or hwmod framework can cause uart to enter recursive pm_runtime calls,
which can cause a deadlock over power lock usage.

For example: Say, uart clocks are cut and we get a print from omap_device_disable
stating disabling uart clocks. This print calls omap_uart driver console_write
which will call runtime API get_sync which means we enter from runtime API put
context to runtime API get context.

--> runtime put (take power lock)
    --> print disabling uart clocks
        --> call uart console write
            --> call get_sync (try to take power lock)

Also any clock enable API call from uart driver should not call any uart
operation until clocks are enabled back. Like get_sync having debug print
calling uart console write even before clocks are enabled.

So to avoid these scenarios, identify from bootargs  if OMAP_UART(ttyO) is used
in debug mode. If so, do not set device_may_wakeup. This will prevent
pm_runtime_enable in uart driver probe and will avoid uart clock gating.

Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
---
More details on this topic and experiments done listed here:
http://www.spinics.net/lists/linux-serial/msg04128.html

 arch/arm/mach-omap2/serial.c |   18 +++++++++++++++++-
 1 files changed, 17 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
index 87696bf..3d92b77f 100644
--- a/arch/arm/mach-omap2/serial.c
+++ b/arch/arm/mach-omap2/serial.c
@@ -266,8 +266,24 @@ struct omap_hwmod *omap_uart_hwmod_lookup(int num)
 	return oh;
 }
 
+static int uart_debug;
+
+char *cmdline_find_option(char *str)
+{
+	extern char *saved_command_line;
+
+	return strstr(saved_command_line, str);
+}
+
 static int __init omap_serial_early_init(void)
 {
+	if (cmdline_find_option("debug") &&
+			cmdline_find_option(OMAP_SERIAL_NAME)) {
+		uart_debug = true;
+		pr_info("OMAP UART used as console in debug mode"
+			" uart clocks will not be gated");
+	}
+
 	do {
 		struct omap_hwmod *oh;
 
@@ -361,7 +377,7 @@ void __init omap_serial_init_port(struct omap_board_data *bdata,
 
 	oh->mux = omap_hwmod_mux_init(bdata->pads, bdata->pads_cnt);
 
-	if ((cpu_is_omap34xx() && bdata->pads))
+	if ((cpu_is_omap34xx() && bdata->pads) && !uart_debug)
 		device_init_wakeup(&pdev->dev, true);
 
 	kfree(pdata);
-- 
1.7.4.1