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path: root/drivers/tty/serial/8250/8250_mid.c
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Diffstat (limited to 'drivers/tty/serial/8250/8250_mid.c')
-rw-r--r--drivers/tty/serial/8250/8250_mid.c258
1 files changed, 258 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_mid.c b/drivers/tty/serial/8250/8250_mid.c
new file mode 100644
index 000000000000..61f604c7aeee
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_mid.c
@@ -0,0 +1,258 @@
+/*
+ * 8250_mid.c - Driver for UART on Intel Penwell and various other Intel SOCs
+ *
+ * Copyright (C) 2015 Intel Corporation
+ * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/rational.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+
+#include <linux/dma/hsu.h>
+
+#include "8250.h"
+
+#define PCI_DEVICE_ID_INTEL_PNW_UART1 0x081b
+#define PCI_DEVICE_ID_INTEL_PNW_UART2 0x081c
+#define PCI_DEVICE_ID_INTEL_PNW_UART3 0x081d
+#define PCI_DEVICE_ID_INTEL_TNG_UART 0x1191
+
+/* Intel MID Specific registers */
+#define INTEL_MID_UART_PS 0x30
+#define INTEL_MID_UART_MUL 0x34
+#define INTEL_MID_UART_DIV 0x38
+
+struct mid8250;
+
+struct mid8250_board {
+ unsigned long freq;
+ unsigned int base_baud;
+ int (*setup)(struct mid8250 *, struct uart_port *p);
+};
+
+struct mid8250 {
+ int line;
+ int dma_index;
+ struct pci_dev *dma_dev;
+ struct uart_8250_dma dma;
+ struct mid8250_board *board;
+};
+
+/*****************************************************************************/
+
+static int pnw_setup(struct mid8250 *mid, struct uart_port *p)
+{
+ struct pci_dev *pdev = to_pci_dev(p->dev);
+
+ switch (pdev->device) {
+ case PCI_DEVICE_ID_INTEL_PNW_UART1:
+ mid->dma_index = 0;
+ break;
+ case PCI_DEVICE_ID_INTEL_PNW_UART2:
+ mid->dma_index = 1;
+ break;
+ case PCI_DEVICE_ID_INTEL_PNW_UART3:
+ mid->dma_index = 2;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ mid->dma_dev = pci_get_slot(pdev->bus,
+ PCI_DEVFN(PCI_SLOT(pdev->devfn), 3));
+ return 0;
+}
+
+static int tng_setup(struct mid8250 *mid, struct uart_port *p)
+{
+ struct pci_dev *pdev = to_pci_dev(p->dev);
+ int index = PCI_FUNC(pdev->devfn);
+
+ /* Currently no support for HSU port0 */
+ if (index-- == 0)
+ return -ENODEV;
+
+ mid->dma_index = index;
+ mid->dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(5, 0));
+ return 0;
+}
+
+/*****************************************************************************/
+
+static void mid8250_set_termios(struct uart_port *p,
+ struct ktermios *termios,
+ struct ktermios *old)
+{
+ unsigned int baud = tty_termios_baud_rate(termios);
+ struct mid8250 *mid = p->private_data;
+ unsigned short ps = 16;
+ unsigned long fuart = baud * ps;
+ unsigned long w = BIT(24) - 1;
+ unsigned long mul, div;
+
+ if (mid->board->freq < fuart) {
+ /* Find prescaler value that satisfies Fuart < Fref */
+ if (mid->board->freq > baud)
+ ps = mid->board->freq / baud; /* baud rate too high */
+ else
+ ps = 1; /* PLL case */
+ fuart = baud * ps;
+ } else {
+ /* Get Fuart closer to Fref */
+ fuart *= rounddown_pow_of_two(mid->board->freq / fuart);
+ }
+
+ rational_best_approximation(fuart, mid->board->freq, w, w, &mul, &div);
+ p->uartclk = fuart * 16 / ps; /* core uses ps = 16 always */
+
+ writel(ps, p->membase + INTEL_MID_UART_PS); /* set PS */
+ writel(mul, p->membase + INTEL_MID_UART_MUL); /* set MUL */
+ writel(div, p->membase + INTEL_MID_UART_DIV);
+
+ serial8250_do_set_termios(p, termios, old);
+}
+
+static bool mid8250_dma_filter(struct dma_chan *chan, void *param)
+{
+ struct hsu_dma_slave *s = param;
+
+ if (s->dma_dev != chan->device->dev || s->chan_id != chan->chan_id)
+ return false;
+
+ chan->private = s;
+ return true;
+}
+
+static int mid8250_dma_setup(struct mid8250 *mid, struct uart_8250_port *port)
+{
+ struct uart_8250_dma *dma = &mid->dma;
+ struct device *dev = port->port.dev;
+ struct hsu_dma_slave *rx_param;
+ struct hsu_dma_slave *tx_param;
+
+ rx_param = devm_kzalloc(dev, sizeof(*rx_param), GFP_KERNEL);
+ if (!rx_param)
+ return -ENOMEM;
+
+ tx_param = devm_kzalloc(dev, sizeof(*tx_param), GFP_KERNEL);
+ if (!tx_param)
+ return -ENOMEM;
+
+ rx_param->chan_id = mid->dma_index * 2 + 1;
+ tx_param->chan_id = mid->dma_index * 2;
+
+ dma->rxconf.src_maxburst = 64;
+ dma->txconf.dst_maxburst = 64;
+
+ rx_param->dma_dev = &mid->dma_dev->dev;
+ tx_param->dma_dev = &mid->dma_dev->dev;
+
+ dma->fn = mid8250_dma_filter;
+ dma->rx_param = rx_param;
+ dma->tx_param = tx_param;
+
+ port->dma = dma;
+ return 0;
+}
+
+static int mid8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+ struct uart_8250_port uart;
+ struct mid8250 *mid;
+ int ret;
+
+ ret = pcim_enable_device(pdev);
+ if (ret)
+ return ret;
+
+ pci_set_master(pdev);
+
+ mid = devm_kzalloc(&pdev->dev, sizeof(*mid), GFP_KERNEL);
+ if (!mid)
+ return -ENOMEM;
+
+ mid->board = (struct mid8250_board *)id->driver_data;
+
+ memset(&uart, 0, sizeof(struct uart_8250_port));
+
+ uart.port.dev = &pdev->dev;
+ uart.port.irq = pdev->irq;
+ uart.port.private_data = mid;
+ uart.port.type = PORT_16750;
+ uart.port.iotype = UPIO_MEM;
+ uart.port.uartclk = mid->board->base_baud * 16;
+ uart.port.flags = UPF_SHARE_IRQ | UPF_FIXED_PORT | UPF_FIXED_TYPE;
+ uart.port.set_termios = mid8250_set_termios;
+
+ uart.port.mapbase = pci_resource_start(pdev, 0);
+ uart.port.membase = pcim_iomap(pdev, 0, 0);
+ if (!uart.port.membase)
+ return -ENOMEM;
+
+ if (mid->board->setup) {
+ ret = mid->board->setup(mid, &uart.port);
+ if (ret)
+ return ret;
+ }
+
+ ret = mid8250_dma_setup(mid, &uart);
+ if (ret)
+ return ret;
+
+ ret = serial8250_register_8250_port(&uart);
+ if (ret < 0)
+ return ret;
+
+ mid->line = ret;
+
+ pci_set_drvdata(pdev, mid);
+ return 0;
+}
+
+static void mid8250_remove(struct pci_dev *pdev)
+{
+ struct mid8250 *mid = pci_get_drvdata(pdev);
+
+ serial8250_unregister_port(mid->line);
+}
+
+static const struct mid8250_board pnw_board = {
+ .freq = 50000000,
+ .base_baud = 115200,
+ .setup = pnw_setup,
+};
+
+static const struct mid8250_board tng_board = {
+ .freq = 38400000,
+ .base_baud = 1843200,
+ .setup = tng_setup,
+};
+
+#define MID_DEVICE(id, board) { PCI_VDEVICE(INTEL, id), (kernel_ulong_t)&board }
+
+static const struct pci_device_id pci_ids[] = {
+ MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART1, pnw_board),
+ MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART2, pnw_board),
+ MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART3, pnw_board),
+ MID_DEVICE(PCI_DEVICE_ID_INTEL_TNG_UART, tng_board),
+ { },
+};
+MODULE_DEVICE_TABLE(pci, pci_ids);
+
+static struct pci_driver mid8250_pci_driver = {
+ .name = "8250_mid",
+ .id_table = pci_ids,
+ .probe = mid8250_probe,
+ .remove = mid8250_remove,
+};
+
+module_pci_driver(mid8250_pci_driver);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Intel MID UART driver");
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-17 02:03:42 +0000