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serial: 8250: Add support for higher baud rates to Pericom chips
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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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Jay Dolan authored and Greg Kroah-Hartman committed Jun 18, 2019
1 parent 4e828c3 commit 6bf4e42
Showing 1 changed file with 79 additions and 18 deletions.
97 changes: 79 additions & 18 deletions drivers/tty/serial/8250/8250_pci.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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, 2, 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;
Expand All @@ -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);
}

Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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
*/
{
Expand Down

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