* [PATCH 2/4] serial: sccnxp: Using CLK API for getting UART clock
2013-07-31 10:56 [PATCH 1/4] serial: sccnxp: Disable regulator on error Alexander Shiyan
@ 2013-07-31 10:56 ` Alexander Shiyan
2013-07-31 10:56 ` [PATCH 3/4] serial: sccnxp: Using structure for each supported IC instead of switch in probe Alexander Shiyan
1 sibling, 0 replies; 3+ messages in thread
From: Alexander Shiyan @ 2013-07-31 10:56 UTC (permalink / raw)
To: linux-serial; +Cc: Greg Kroah-Hartman, Jiri Slaby, Alexander Shiyan
This patch removes "frequency" parameter from SCCNXP platform_data
and uses CLK API for getting clock. If CLK ommited, default IC
frequency will be used instead.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
---
arch/mips/sni/a20r.c | 1 -
drivers/tty/serial/sccnxp.c | 36 ++++++++++++++++++-----------
include/linux/platform_data/serial-sccnxp.h | 3 ---
3 files changed, 22 insertions(+), 18 deletions(-)
diff --git a/arch/mips/sni/a20r.c b/arch/mips/sni/a20r.c
index dd0ab98..f9407e1 100644
--- a/arch/mips/sni/a20r.c
+++ b/arch/mips/sni/a20r.c
@@ -122,7 +122,6 @@ static struct resource sc26xx_rsrc[] = {
static struct sccnxp_pdata sccnxp_data = {
.reg_shift = 2,
- .frequency = 3686400,
.mctrl_cfg[0] = MCTRL_SIG(DTR_OP, LINE_OP7) |
MCTRL_SIG(RTS_OP, LINE_OP3) |
MCTRL_SIG(DSR_IP, LINE_IP5) |
diff --git a/drivers/tty/serial/sccnxp.c b/drivers/tty/serial/sccnxp.c
index 12a5c26..81e7047 100644
--- a/drivers/tty/serial/sccnxp.c
+++ b/drivers/tty/serial/sccnxp.c
@@ -15,6 +15,7 @@
#define SUPPORT_SYSRQ
#endif
+#include <linux/clk.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/device.h>
@@ -783,9 +784,10 @@ static int sccnxp_probe(struct platform_device *pdev)
struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
int chiptype = pdev->id_entry->driver_data;
struct sccnxp_pdata *pdata = dev_get_platdata(&pdev->dev);
- int i, ret, fifosize, freq_min, freq_max;
+ int i, ret, fifosize, freq_min, freq_max, uartclk;
struct sccnxp_port *s;
void __iomem *membase;
+ struct clk *clk;
membase = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(membase))
@@ -898,11 +900,25 @@ static int sccnxp_probe(struct platform_device *pdev)
} else if (PTR_ERR(s->regulator) == -EPROBE_DEFER)
return -EPROBE_DEFER;
- if (!pdata) {
- dev_warn(&pdev->dev,
- "No platform data supplied, using defaults\n");
- s->pdata.frequency = s->freq_std;
+ clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(clk)) {
+ if (PTR_ERR(clk) == -EPROBE_DEFER) {
+ ret = -EPROBE_DEFER;
+ goto err_out;
+ }
+ dev_notice(&pdev->dev, "Using default clock frequency\n");
+ uartclk = s->freq_std;
} else
+ uartclk = clk_get_rate(clk);
+
+ /* Check input frequency */
+ if ((uartclk < freq_min) || (uartclk > freq_max)) {
+ dev_err(&pdev->dev, "Frequency out of bounds\n");
+ ret = -EINVAL;
+ goto err_out;
+ }
+
+ if (pdata)
memcpy(&s->pdata, pdata, sizeof(struct sccnxp_pdata));
if (s->pdata.poll_time_us) {
@@ -920,14 +936,6 @@ static int sccnxp_probe(struct platform_device *pdev)
}
}
- /* Check input frequency */
- if ((s->pdata.frequency < freq_min) ||
- (s->pdata.frequency > freq_max)) {
- dev_err(&pdev->dev, "Frequency out of bounds\n");
- ret = -EINVAL;
- goto err_out;
- }
-
s->uart.owner = THIS_MODULE;
s->uart.dev_name = "ttySC";
s->uart.major = SCCNXP_MAJOR;
@@ -959,7 +967,7 @@ static int sccnxp_probe(struct platform_device *pdev)
s->port[i].mapbase = res->start;
s->port[i].membase = membase;
s->port[i].regshift = s->pdata.reg_shift;
- s->port[i].uartclk = s->pdata.frequency;
+ s->port[i].uartclk = uartclk;
s->port[i].ops = &sccnxp_ops;
uart_add_one_port(&s->uart, &s->port[i]);
/* Set direction to input */
diff --git a/include/linux/platform_data/serial-sccnxp.h b/include/linux/platform_data/serial-sccnxp.h
index bdc510d..af0c8c3 100644
--- a/include/linux/platform_data/serial-sccnxp.h
+++ b/include/linux/platform_data/serial-sccnxp.h
@@ -60,7 +60,6 @@
* };
*
* static struct sccnxp_pdata sc2892_info = {
- * .frequency = 3686400,
* .mctrl_cfg[0] = MCTRL_SIG(DIR_OP, LINE_OP0),
* .mctrl_cfg[1] = MCTRL_SIG(DIR_OP, LINE_OP1),
* };
@@ -78,8 +77,6 @@
/* SCCNXP platform data structure */
struct sccnxp_pdata {
- /* Frequency (extrenal clock or crystal) */
- int frequency;
/* Shift for A0 line */
const u8 reg_shift;
/* Modem control lines configuration */
--
1.8.1.5
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH 3/4] serial: sccnxp: Using structure for each supported IC instead of switch in probe
2013-07-31 10:56 [PATCH 1/4] serial: sccnxp: Disable regulator on error Alexander Shiyan
2013-07-31 10:56 ` [PATCH 2/4] serial: sccnxp: Using CLK API for getting UART clock Alexander Shiyan
@ 2013-07-31 10:56 ` Alexander Shiyan
1 sibling, 0 replies; 3+ messages in thread
From: Alexander Shiyan @ 2013-07-31 10:56 UTC (permalink / raw)
To: linux-serial; +Cc: Greg Kroah-Hartman, Jiri Slaby, Alexander Shiyan
This patch replaces switch in probe function to constant structure
for each supported IC. This makes code a bit smaller and cleaner and
helps adding DT support to the driver in the future.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
---
drivers/tty/serial/sccnxp.c | 272 ++++++++++++++++++++------------------------
1 file changed, 124 insertions(+), 148 deletions(-)
diff --git a/drivers/tty/serial/sccnxp.c b/drivers/tty/serial/sccnxp.c
index 81e7047..ef53c7a 100644
--- a/drivers/tty/serial/sccnxp.c
+++ b/drivers/tty/serial/sccnxp.c
@@ -95,16 +95,17 @@
#define MCTRL_IBIT(cfg, sig) ((((cfg) >> (sig)) & 0xf) - LINE_IP0)
#define MCTRL_OBIT(cfg, sig) ((((cfg) >> (sig)) & 0xf) - LINE_OP0)
-/* Supported chip types */
-enum {
- SCCNXP_TYPE_SC2681 = 2681,
- SCCNXP_TYPE_SC2691 = 2691,
- SCCNXP_TYPE_SC2692 = 2692,
- SCCNXP_TYPE_SC2891 = 2891,
- SCCNXP_TYPE_SC2892 = 2892,
- SCCNXP_TYPE_SC28202 = 28202,
- SCCNXP_TYPE_SC68681 = 68681,
- SCCNXP_TYPE_SC68692 = 68692,
+#define SCCNXP_HAVE_IO 0x00000001
+#define SCCNXP_HAVE_MR0 0x00000002
+
+struct sccnxp_chip {
+ const char *name;
+ unsigned int nr;
+ unsigned long freq_min;
+ unsigned long freq_std;
+ unsigned long freq_max;
+ unsigned int flags;
+ unsigned int fifosize;
};
struct sccnxp_port {
@@ -112,16 +113,10 @@ struct sccnxp_port {
struct uart_port port[SCCNXP_MAX_UARTS];
bool opened[SCCNXP_MAX_UARTS];
- const char *name;
int irq;
-
u8 imr;
- u8 addr_mask;
- int freq_std;
- int flags;
-#define SCCNXP_HAVE_IO 0x00000001
-#define SCCNXP_HAVE_MR0 0x00000002
+ struct sccnxp_chip *chip;
#ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
struct console console;
@@ -137,29 +132,94 @@ struct sccnxp_port {
struct regulator *regulator;
};
-static inline u8 sccnxp_raw_read(void __iomem *base, u8 reg, u8 shift)
-{
- return readb(base + (reg << shift));
-}
+static const struct sccnxp_chip sc2681 = {
+ .name = "SC2681",
+ .nr = 2,
+ .freq_min = 1000000,
+ .freq_std = 3686400,
+ .freq_max = 4000000,
+ .flags = SCCNXP_HAVE_IO,
+ .fifosize = 3,
+};
-static inline void sccnxp_raw_write(void __iomem *base, u8 reg, u8 shift, u8 v)
-{
- writeb(v, base + (reg << shift));
-}
+static const struct sccnxp_chip sc2691 = {
+ .name = "SC2691",
+ .nr = 1,
+ .freq_min = 1000000,
+ .freq_std = 3686400,
+ .freq_max = 4000000,
+ .flags = 0,
+ .fifosize = 3,
+};
+
+static const struct sccnxp_chip sc2692 = {
+ .name = "SC2692",
+ .nr = 2,
+ .freq_min = 1000000,
+ .freq_std = 3686400,
+ .freq_max = 4000000,
+ .flags = SCCNXP_HAVE_IO,
+ .fifosize = 3,
+};
+
+static const struct sccnxp_chip sc2891 = {
+ .name = "SC2891",
+ .nr = 1,
+ .freq_min = 100000,
+ .freq_std = 3686400,
+ .freq_max = 8000000,
+ .flags = SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
+ .fifosize = 16,
+};
+
+static const struct sccnxp_chip sc2892 = {
+ .name = "SC2892",
+ .nr = 2,
+ .freq_min = 100000,
+ .freq_std = 3686400,
+ .freq_max = 8000000,
+ .flags = SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
+ .fifosize = 16,
+};
+
+static const struct sccnxp_chip sc28202 = {
+ .name = "SC28202",
+ .nr = 2,
+ .freq_min = 1000000,
+ .freq_std = 14745600,
+ .freq_max = 50000000,
+ .flags = SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
+ .fifosize = 256,
+};
+
+static const struct sccnxp_chip sc68681 = {
+ .name = "SC68681",
+ .nr = 2,
+ .freq_min = 1000000,
+ .freq_std = 3686400,
+ .freq_max = 4000000,
+ .flags = SCCNXP_HAVE_IO,
+ .fifosize = 3,
+};
+
+static const struct sccnxp_chip sc68692 = {
+ .name = "SC68692",
+ .nr = 2,
+ .freq_min = 1000000,
+ .freq_std = 3686400,
+ .freq_max = 4000000,
+ .flags = SCCNXP_HAVE_IO,
+ .fifosize = 3,
+};
static inline u8 sccnxp_read(struct uart_port *port, u8 reg)
{
- struct sccnxp_port *s = dev_get_drvdata(port->dev);
-
- return sccnxp_raw_read(port->membase, reg & s->addr_mask,
- port->regshift);
+ return readb(port->membase + (reg << port->regshift));
}
static inline void sccnxp_write(struct uart_port *port, u8 reg, u8 v)
{
- struct sccnxp_port *s = dev_get_drvdata(port->dev);
-
- sccnxp_raw_write(port->membase, reg & s->addr_mask, port->regshift, v);
+ writeb(v, port->membase + (reg << port->regshift));
}
static inline u8 sccnxp_port_read(struct uart_port *port, u8 reg)
@@ -225,13 +285,14 @@ static int sccnxp_set_baud(struct uart_port *port, int baud)
{
struct sccnxp_port *s = dev_get_drvdata(port->dev);
int div_std, tmp_baud, bestbaud = baud, besterr = -1;
+ struct sccnxp_chip *chip = s->chip;
u8 i, acr = 0, csr = 0, mr0 = 0;
/* Find best baud from table */
for (i = 0; baud_std[i].baud && besterr; i++) {
- if (baud_std[i].mr0 && !(s->flags & SCCNXP_HAVE_MR0))
+ if (baud_std[i].mr0 && !(chip->flags & SCCNXP_HAVE_MR0))
continue;
- div_std = DIV_ROUND_CLOSEST(s->freq_std, baud_std[i].baud);
+ div_std = DIV_ROUND_CLOSEST(chip->freq_std, baud_std[i].baud);
tmp_baud = DIV_ROUND_CLOSEST(port->uartclk, div_std);
if (!sccnxp_update_best_err(baud, tmp_baud, &besterr)) {
acr = baud_std[i].acr;
@@ -241,7 +302,7 @@ static int sccnxp_set_baud(struct uart_port *port, int baud)
}
}
- if (s->flags & SCCNXP_HAVE_MR0) {
+ if (chip->flags & SCCNXP_HAVE_MR0) {
/* Enable FIFO, set half level for TX */
mr0 |= MR0_FIFO | MR0_TXLVL;
/* Update MR0 */
@@ -364,7 +425,7 @@ static void sccnxp_handle_tx(struct uart_port *port)
sccnxp_disable_irq(port, IMR_TXRDY);
/* Set direction to input */
- if (s->flags & SCCNXP_HAVE_IO)
+ if (s->chip->flags & SCCNXP_HAVE_IO)
sccnxp_set_bit(port, DIR_OP, 0);
}
return;
@@ -438,7 +499,7 @@ static void sccnxp_start_tx(struct uart_port *port)
spin_lock_irqsave(&s->lock, flags);
/* Set direction to output */
- if (s->flags & SCCNXP_HAVE_IO)
+ if (s->chip->flags & SCCNXP_HAVE_IO)
sccnxp_set_bit(port, DIR_OP, 1);
sccnxp_enable_irq(port, IMR_TXRDY);
@@ -484,7 +545,7 @@ static void sccnxp_set_mctrl(struct uart_port *port, unsigned int mctrl)
struct sccnxp_port *s = dev_get_drvdata(port->dev);
unsigned long flags;
- if (!(s->flags & SCCNXP_HAVE_IO))
+ if (!(s->chip->flags & SCCNXP_HAVE_IO))
return;
spin_lock_irqsave(&s->lock, flags);
@@ -502,7 +563,7 @@ static unsigned int sccnxp_get_mctrl(struct uart_port *port)
struct sccnxp_port *s = dev_get_drvdata(port->dev);
unsigned int mctrl = TIOCM_DSR | TIOCM_CTS | TIOCM_CAR;
- if (!(s->flags & SCCNXP_HAVE_IO))
+ if (!(s->chip->flags & SCCNXP_HAVE_IO))
return mctrl;
spin_lock_irqsave(&s->lock, flags);
@@ -618,7 +679,7 @@ static void sccnxp_set_termios(struct uart_port *port,
/* Setup baudrate */
baud = uart_get_baud_rate(port, termios, old, 50,
- (s->flags & SCCNXP_HAVE_MR0) ?
+ (s->chip->flags & SCCNXP_HAVE_MR0) ?
230400 : 38400);
baud = sccnxp_set_baud(port, baud);
@@ -642,7 +703,7 @@ static int sccnxp_startup(struct uart_port *port)
spin_lock_irqsave(&s->lock, flags);
- if (s->flags & SCCNXP_HAVE_IO) {
+ if (s->chip->flags & SCCNXP_HAVE_IO) {
/* Outputs are controlled manually */
sccnxp_write(port, SCCNXP_OPCR_REG, 0);
}
@@ -682,7 +743,7 @@ static void sccnxp_shutdown(struct uart_port *port)
sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_DISABLE | CR_TX_DISABLE);
/* Leave direction to input */
- if (s->flags & SCCNXP_HAVE_IO)
+ if (s->chip->flags & SCCNXP_HAVE_IO)
sccnxp_set_bit(port, DIR_OP, 0);
spin_unlock_irqrestore(&s->lock, flags);
@@ -692,7 +753,7 @@ static const char *sccnxp_type(struct uart_port *port)
{
struct sccnxp_port *s = dev_get_drvdata(port->dev);
- return (port->type == PORT_SC26XX) ? s->name : NULL;
+ return (port->type == PORT_SC26XX) ? s->chip->name : NULL;
}
static void sccnxp_release_port(struct uart_port *port)
@@ -779,12 +840,24 @@ static int sccnxp_console_setup(struct console *co, char *options)
}
#endif
+static const struct platform_device_id sccnxp_id_table[] = {
+ { .name = "sc2681", .driver_data = (kernel_ulong_t)&sc2681, },
+ { .name = "sc2691", .driver_data = (kernel_ulong_t)&sc2691, },
+ { .name = "sc2692", .driver_data = (kernel_ulong_t)&sc2692, },
+ { .name = "sc2891", .driver_data = (kernel_ulong_t)&sc2891, },
+ { .name = "sc2892", .driver_data = (kernel_ulong_t)&sc2892, },
+ { .name = "sc28202", .driver_data = (kernel_ulong_t)&sc28202, },
+ { .name = "sc68681", .driver_data = (kernel_ulong_t)&sc68681, },
+ { .name = "sc68692", .driver_data = (kernel_ulong_t)&sc68692, },
+ { }
+};
+MODULE_DEVICE_TABLE(platform, sccnxp_id_table);
+
static int sccnxp_probe(struct platform_device *pdev)
{
struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- int chiptype = pdev->id_entry->driver_data;
struct sccnxp_pdata *pdata = dev_get_platdata(&pdev->dev);
- int i, ret, fifosize, freq_min, freq_max, uartclk;
+ int i, ret, uartclk;
struct sccnxp_port *s;
void __iomem *membase;
struct clk *clk;
@@ -802,92 +875,7 @@ static int sccnxp_probe(struct platform_device *pdev)
spin_lock_init(&s->lock);
- /* Individual chip settings */
- switch (chiptype) {
- case SCCNXP_TYPE_SC2681:
- s->name = "SC2681";
- s->uart.nr = 2;
- s->freq_std = 3686400;
- s->addr_mask = 0x0f;
- s->flags = SCCNXP_HAVE_IO;
- fifosize = 3;
- freq_min = 1000000;
- freq_max = 4000000;
- break;
- case SCCNXP_TYPE_SC2691:
- s->name = "SC2691";
- s->uart.nr = 1;
- s->freq_std = 3686400;
- s->addr_mask = 0x07;
- s->flags = 0;
- fifosize = 3;
- freq_min = 1000000;
- freq_max = 4000000;
- break;
- case SCCNXP_TYPE_SC2692:
- s->name = "SC2692";
- s->uart.nr = 2;
- s->freq_std = 3686400;
- s->addr_mask = 0x0f;
- s->flags = SCCNXP_HAVE_IO;
- fifosize = 3;
- freq_min = 1000000;
- freq_max = 4000000;
- break;
- case SCCNXP_TYPE_SC2891:
- s->name = "SC2891";
- s->uart.nr = 1;
- s->freq_std = 3686400;
- s->addr_mask = 0x0f;
- s->flags = SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0;
- fifosize = 16;
- freq_min = 100000;
- freq_max = 8000000;
- break;
- case SCCNXP_TYPE_SC2892:
- s->name = "SC2892";
- s->uart.nr = 2;
- s->freq_std = 3686400;
- s->addr_mask = 0x0f;
- s->flags = SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0;
- fifosize = 16;
- freq_min = 100000;
- freq_max = 8000000;
- break;
- case SCCNXP_TYPE_SC28202:
- s->name = "SC28202";
- s->uart.nr = 2;
- s->freq_std = 14745600;
- s->addr_mask = 0x7f;
- s->flags = SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0;
- fifosize = 256;
- freq_min = 1000000;
- freq_max = 50000000;
- break;
- case SCCNXP_TYPE_SC68681:
- s->name = "SC68681";
- s->uart.nr = 2;
- s->freq_std = 3686400;
- s->addr_mask = 0x0f;
- s->flags = SCCNXP_HAVE_IO;
- fifosize = 3;
- freq_min = 1000000;
- freq_max = 4000000;
- break;
- case SCCNXP_TYPE_SC68692:
- s->name = "SC68692";
- s->uart.nr = 2;
- s->freq_std = 3686400;
- s->addr_mask = 0x0f;
- s->flags = SCCNXP_HAVE_IO;
- fifosize = 3;
- freq_min = 1000000;
- freq_max = 4000000;
- break;
- default:
- dev_err(&pdev->dev, "Unsupported chip type %i\n", chiptype);
- return -ENOTSUPP;
- }
+ s->chip = (struct sccnxp_chip *)pdev->id_entry->driver_data;
s->regulator = devm_regulator_get(&pdev->dev, "vcc");
if (!IS_ERR(s->regulator)) {
@@ -907,12 +895,12 @@ static int sccnxp_probe(struct platform_device *pdev)
goto err_out;
}
dev_notice(&pdev->dev, "Using default clock frequency\n");
- uartclk = s->freq_std;
+ uartclk = s->chip->freq_std;
} else
uartclk = clk_get_rate(clk);
/* Check input frequency */
- if ((uartclk < freq_min) || (uartclk > freq_max)) {
+ if ((uartclk < s->chip->freq_min) || (uartclk > s->chip->freq_max)) {
dev_err(&pdev->dev, "Frequency out of bounds\n");
ret = -EINVAL;
goto err_out;
@@ -940,6 +928,7 @@ static int sccnxp_probe(struct platform_device *pdev)
s->uart.dev_name = "ttySC";
s->uart.major = SCCNXP_MAJOR;
s->uart.minor = SCCNXP_MINOR;
+ s->uart.nr = s->chip->nr;
#ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
s->uart.cons = &s->console;
s->uart.cons->device = uart_console_device;
@@ -961,7 +950,7 @@ static int sccnxp_probe(struct platform_device *pdev)
s->port[i].dev = &pdev->dev;
s->port[i].irq = s->irq;
s->port[i].type = PORT_SC26XX;
- s->port[i].fifosize = fifosize;
+ s->port[i].fifosize = s->chip->fifosize;
s->port[i].flags = UPF_SKIP_TEST | UPF_FIXED_TYPE;
s->port[i].iotype = UPIO_MEM;
s->port[i].mapbase = res->start;
@@ -971,7 +960,7 @@ static int sccnxp_probe(struct platform_device *pdev)
s->port[i].ops = &sccnxp_ops;
uart_add_one_port(&s->uart, &s->port[i]);
/* Set direction to input */
- if (s->flags & SCCNXP_HAVE_IO)
+ if (s->chip->flags & SCCNXP_HAVE_IO)
sccnxp_set_bit(&s->port[i], DIR_OP, 0);
}
@@ -1025,19 +1014,6 @@ static int sccnxp_remove(struct platform_device *pdev)
return 0;
}
-static const struct platform_device_id sccnxp_id_table[] = {
- { "sc2681", SCCNXP_TYPE_SC2681 },
- { "sc2691", SCCNXP_TYPE_SC2691 },
- { "sc2692", SCCNXP_TYPE_SC2692 },
- { "sc2891", SCCNXP_TYPE_SC2891 },
- { "sc2892", SCCNXP_TYPE_SC2892 },
- { "sc28202", SCCNXP_TYPE_SC28202 },
- { "sc68681", SCCNXP_TYPE_SC68681 },
- { "sc68692", SCCNXP_TYPE_SC68692 },
- { },
-};
-MODULE_DEVICE_TABLE(platform, sccnxp_id_table);
-
static struct platform_driver sccnxp_uart_driver = {
.driver = {
.name = SCCNXP_NAME,
--
1.8.1.5
^ permalink raw reply related [flat|nested] 3+ messages in thread