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List: linux-serial
Subject: [PATCH v3 1/1] serial: 8250: Add support for higher baud rates to Pericom chips
From: jay.dolan () accesio ! com
Date: 2019-05-28 3:59:43
Message-ID: 20190528035943.6274-2-jay.dolan () accesio ! com
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From: Jay Dolan <jay.dolan@accesio.com>
The Pericom chips can achieve additional baud rates by programming the
sample clock register. The baud rates can be described as
921600 * 16 / (16 - scr) for scr values 5 to 15. The divisor is set to 1
for these baud rates.
Adds new quirk for Pericom chips other than the four port chips to use
the
Signed-off-by: Jay Dolan <jay.dolan@accesio.com>
---
drivers/tty/serial/8250/8250_pci.c | 97 ++++++++++++++++++++++++------
1 file changed, 79 insertions(+), 18 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index df41397de478..9a895ae449c5 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -1326,13 +1326,66 @@ static int pci_default_setup(struct serial_private *priv,
return setup_port(priv, port, bar, offset, board->reg_shift);
}
-
+void
+pericom_do_set_divisor(struct uart_port *port, unsigned int baud,
+ unsigned int quot, unsigned int quot_frac)
+{
+ int scr;
+ int lcr;
+ int actual_baud;
+ int tolerance;
+
+ for (scr = 5 ; scr <= 15 ; scr++) {
+ actual_baud = 921600 * 16 / scr;
+ tolerance = actual_baud / 50;
+
+ if ((baud < actual_baud + tolerance) &&
+ (baud > actual_baud - tolerance)) {
+
+ lcr = serial_port_in(port, UART_LCR);
+ serial_port_out(port, UART_LCR, lcr | 0x80);
+
+ serial_port_out(port, UART_DLL, 1);
+ serial_port_out(port, UART_DLM, 0);
+ serial_port_out(port, UART_PCM_SCR, 16 - scr);
+ serial_port_out(port, UART_LCR, lcr);
+ return;
+ } else if (baud > actual_baud) {
+ break;
+ }
+ }
+ serial8250_do_set_divisor(port, baud, quot, quot_frac);
+}
static int pci_pericom_setup(struct serial_private *priv,
const struct pciserial_board *board,
struct uart_8250_port *port, int idx)
{
unsigned int bar, offset = board->first_offset, maxnr;
+ bar = FL_GET_BASE(board->flags);
+ if (board->flags & FL_BASE_BARS)
+ bar += idx;
+ else
+ offset += idx * board->uart_offset;
+
+
+ maxnr = (pci_resource_len(priv->dev, bar) - board->first_offset) >>
+ (board->reg_shift + 3);
+
+ if (board->flags & FL_REGION_SZ_CAP && idx >= maxnr)
+ return 1;
+
+ port->port.set_divisor = pericom_do_set_divisor;
+
+ return setup_port(priv, port, bar, offset, board->reg_shift);
+}
+
+static int pci_pericom_setup_four_at_eight(struct serial_private *priv,
+ const struct pciserial_board *board,
+ struct uart_8250_port *port, int idx)
+{
+ unsigned int bar, offset = board->first_offset, maxnr;
+
bar = FL_GET_BASE(board->flags);
if (board->flags & FL_BASE_BARS)
bar += idx;
@@ -1348,6 +1401,8 @@ static int pci_pericom_setup(struct serial_private *priv,
if (board->flags & FL_REGION_SZ_CAP && idx >= maxnr)
return 1;
+ port->port.set_divisor = pericom_do_set_divisor;
+
return setup_port(priv, port, bar, offset, board->reg_shift);
}
@@ -1995,7 +2050,7 @@ static struct pci_serial_quirk pci_serial_quirks[] __refdata = {
.device = PCI_DEVICE_ID_PERICOM_PI7C9X7954,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
- .setup = pci_pericom_setup,
+ .setup = pci_pericom_setup_four_at_eight,
},
/*
* PLX
@@ -2032,107 +2087,113 @@ static struct pci_serial_quirk pci_serial_quirks[] __refdata = {
.device = PCI_DEVICE_ID_ACCESIO_PCIE_COM_4SDB,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
- .setup = pci_pericom_setup,
+ .setup = pci_pericom_setup_four_at_eight,
},
{
.vendor = PCI_VENDOR_ID_ACCESIO,
.device = PCI_DEVICE_ID_ACCESIO_MPCIE_COM_4S,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
- .setup = pci_pericom_setup,
+ .setup = pci_pericom_setup_four_at_eight,
},
{
.vendor = PCI_VENDOR_ID_ACCESIO,
.device = PCI_DEVICE_ID_ACCESIO_PCIE_COM232_4DB,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
- .setup = pci_pericom_setup,
+ .setup = pci_pericom_setup_four_at_eight,
},
{
.vendor = PCI_VENDOR_ID_ACCESIO,
.device = PCI_DEVICE_ID_ACCESIO_MPCIE_COM232_4,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
- .setup = pci_pericom_setup,
+ .setup = pci_pericom_setup_four_at_eight,
},
{
.vendor = PCI_VENDOR_ID_ACCESIO,
.device = PCI_DEVICE_ID_ACCESIO_PCIE_COM_4SMDB,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
- .setup = pci_pericom_setup,
+ .setup = pci_pericom_setup_four_at_eight,
},
{
.vendor = PCI_VENDOR_ID_ACCESIO,
.device = PCI_DEVICE_ID_ACCESIO_MPCIE_COM_4SM,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
- .setup = pci_pericom_setup,
+ .setup = pci_pericom_setup_four_at_eight,
},
{
.vendor = PCI_VENDOR_ID_ACCESIO,
.device = PCI_DEVICE_ID_ACCESIO_MPCIE_ICM422_4,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
- .setup = pci_pericom_setup,
+ .setup = pci_pericom_setup_four_at_eight,
},
{
.vendor = PCI_VENDOR_ID_ACCESIO,
.device = PCI_DEVICE_ID_ACCESIO_MPCIE_ICM485_4,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
- .setup = pci_pericom_setup,
+ .setup = pci_pericom_setup_four_at_eight,
},
{
.vendor = PCI_DEVICE_ID_ACCESIO_PCIE_ICM_4S,
.device = PCI_DEVICE_ID_ACCESIO_PCIE_ICM232_4,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
- .setup = pci_pericom_setup,
+ .setup = pci_pericom_setup_four_at_eight,
},
{
.vendor = PCI_VENDOR_ID_ACCESIO,
.device = PCI_DEVICE_ID_ACCESIO_MPCIE_ICM232_4,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
- .setup = pci_pericom_setup,
+ .setup = pci_pericom_setup_four_at_eight,
},
{
.vendor = PCI_VENDOR_ID_ACCESIO,
.device = PCI_DEVICE_ID_ACCESIO_PCIE_COM422_4,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
- .setup = pci_pericom_setup,
+ .setup = pci_pericom_setup_four_at_eight,
},
{
.vendor = PCI_VENDOR_ID_ACCESIO,
.device = PCI_DEVICE_ID_ACCESIO_PCIE_COM485_4,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
- .setup = pci_pericom_setup,
+ .setup = pci_pericom_setup_four_at_eight,
},
{
.vendor = PCI_VENDOR_ID_ACCESIO,
.device = PCI_DEVICE_ID_ACCESIO_PCIE_COM232_4,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
- .setup = pci_pericom_setup,
+ .setup = pci_pericom_setup_four_at_eight,
},
{
.vendor = PCI_VENDOR_ID_ACCESIO,
.device = PCI_DEVICE_ID_ACCESIO_PCIE_COM_4SM,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
- .setup = pci_pericom_setup,
+ .setup = pci_pericom_setup_four_at_eight,
},
{
.vendor = PCI_VENDOR_ID_ACCESIO,
.device = PCI_DEVICE_ID_ACCESIO_PCIE_ICM_4SM,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
- .setup = pci_pericom_setup,
+ .setup = pci_pericom_setup_four_at_eight,
},
- /*
+ {
+ .vendor = PCI_VENDOR_ID_ACCESIO,
+ .device = PCI_ANY_ID,
+ .subvendor = PCI_ANY_ID,
+ .subdevice = PCI_ANY_ID,
+ .setup = pci_pericom_setup,
+ }, /*
* SBS Technologies, Inc., PMC-OCTALPRO 232
*/
{
--
2.17.1
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