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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/tty/serial/8250/8250_lpss.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/tty/serial/8250/8250_lpss.c')
-rw-r--r--drivers/tty/serial/8250/8250_lpss.c437
1 files changed, 437 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c
new file mode 100644
index 0000000000..0e43bdfb74
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_lpss.c
@@ -0,0 +1,437 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 8250_lpss.c - Driver for UART on Intel Braswell and various other Intel SoCs
+ *
+ * Copyright (C) 2016 Intel Corporation
+ * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/rational.h>
+
+#include <linux/dmaengine.h>
+#include <linux/dma/dw.h>
+
+#include "8250_dwlib.h"
+
+#define PCI_DEVICE_ID_INTEL_QRK_UARTx 0x0936
+
+#define PCI_DEVICE_ID_INTEL_BYT_UART1 0x0f0a
+#define PCI_DEVICE_ID_INTEL_BYT_UART2 0x0f0c
+
+#define PCI_DEVICE_ID_INTEL_BSW_UART1 0x228a
+#define PCI_DEVICE_ID_INTEL_BSW_UART2 0x228c
+
+#define PCI_DEVICE_ID_INTEL_EHL_UART0 0x4b96
+#define PCI_DEVICE_ID_INTEL_EHL_UART1 0x4b97
+#define PCI_DEVICE_ID_INTEL_EHL_UART2 0x4b98
+#define PCI_DEVICE_ID_INTEL_EHL_UART3 0x4b99
+#define PCI_DEVICE_ID_INTEL_EHL_UART4 0x4b9a
+#define PCI_DEVICE_ID_INTEL_EHL_UART5 0x4b9b
+
+#define PCI_DEVICE_ID_INTEL_BDW_UART1 0x9ce3
+#define PCI_DEVICE_ID_INTEL_BDW_UART2 0x9ce4
+
+/* Intel LPSS specific registers */
+
+#define BYT_PRV_CLK 0x800
+#define BYT_PRV_CLK_EN BIT(0)
+#define BYT_PRV_CLK_M_VAL_SHIFT 1
+#define BYT_PRV_CLK_N_VAL_SHIFT 16
+#define BYT_PRV_CLK_UPDATE BIT(31)
+
+#define BYT_TX_OVF_INT 0x820
+#define BYT_TX_OVF_INT_MASK BIT(1)
+
+struct lpss8250;
+
+struct lpss8250_board {
+ unsigned long freq;
+ unsigned int base_baud;
+ int (*setup)(struct lpss8250 *, struct uart_port *p);
+ void (*exit)(struct lpss8250 *);
+};
+
+struct lpss8250 {
+ struct dw8250_port_data data;
+ struct lpss8250_board *board;
+
+ /* DMA parameters */
+ struct dw_dma_chip dma_chip;
+ struct dw_dma_slave dma_param;
+ u8 dma_maxburst;
+};
+
+static inline struct lpss8250 *to_lpss8250(struct dw8250_port_data *data)
+{
+ return container_of(data, struct lpss8250, data);
+}
+
+static void byt_set_termios(struct uart_port *p, struct ktermios *termios,
+ const struct ktermios *old)
+{
+ unsigned int baud = tty_termios_baud_rate(termios);
+ struct lpss8250 *lpss = to_lpss8250(p->private_data);
+ unsigned long fref = lpss->board->freq, fuart = baud * 16;
+ unsigned long w = BIT(15) - 1;
+ unsigned long m, n;
+ u32 reg;
+
+ /* Gracefully handle the B0 case: fall back to B9600 */
+ fuart = fuart ? fuart : 9600 * 16;
+
+ /* Get Fuart closer to Fref */
+ fuart *= rounddown_pow_of_two(fref / fuart);
+
+ /*
+ * For baud rates 0.5M, 1M, 1.5M, 2M, 2.5M, 3M, 3.5M and 4M the
+ * dividers must be adjusted.
+ *
+ * uartclk = (m / n) * 100 MHz, where m <= n
+ */
+ rational_best_approximation(fuart, fref, w, w, &m, &n);
+ p->uartclk = fuart;
+
+ /* Reset the clock */
+ reg = (m << BYT_PRV_CLK_M_VAL_SHIFT) | (n << BYT_PRV_CLK_N_VAL_SHIFT);
+ writel(reg, p->membase + BYT_PRV_CLK);
+ reg |= BYT_PRV_CLK_EN | BYT_PRV_CLK_UPDATE;
+ writel(reg, p->membase + BYT_PRV_CLK);
+
+ dw8250_do_set_termios(p, termios, old);
+}
+
+static unsigned int byt_get_mctrl(struct uart_port *port)
+{
+ unsigned int ret = serial8250_do_get_mctrl(port);
+
+ /* Force DCD and DSR signals to permanently be reported as active */
+ ret |= TIOCM_CAR | TIOCM_DSR;
+
+ return ret;
+}
+
+static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
+{
+ struct dw_dma_slave *param = &lpss->dma_param;
+ struct pci_dev *pdev = to_pci_dev(port->dev);
+ struct pci_dev *dma_dev;
+
+ switch (pdev->device) {
+ case PCI_DEVICE_ID_INTEL_BYT_UART1:
+ case PCI_DEVICE_ID_INTEL_BSW_UART1:
+ case PCI_DEVICE_ID_INTEL_BDW_UART1:
+ param->src_id = 3;
+ param->dst_id = 2;
+ break;
+ case PCI_DEVICE_ID_INTEL_BYT_UART2:
+ case PCI_DEVICE_ID_INTEL_BSW_UART2:
+ case PCI_DEVICE_ID_INTEL_BDW_UART2:
+ param->src_id = 5;
+ param->dst_id = 4;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(PCI_SLOT(pdev->devfn), 0));
+
+ param->dma_dev = &dma_dev->dev;
+ param->m_master = 0;
+ param->p_master = 1;
+
+ lpss->dma_maxburst = 16;
+
+ port->set_termios = byt_set_termios;
+ port->get_mctrl = byt_get_mctrl;
+
+ /* Disable TX counter interrupts */
+ writel(BYT_TX_OVF_INT_MASK, port->membase + BYT_TX_OVF_INT);
+
+ return 0;
+}
+
+static void byt_serial_exit(struct lpss8250 *lpss)
+{
+ struct dw_dma_slave *param = &lpss->dma_param;
+
+ /* Paired with pci_get_slot() in the byt_serial_setup() above */
+ put_device(param->dma_dev);
+}
+
+static int ehl_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
+{
+ struct uart_8250_dma *dma = &lpss->data.dma;
+ struct uart_8250_port *up = up_to_u8250p(port);
+
+ /*
+ * This simply makes the checks in the 8250_port to try the DMA
+ * channel request which in turn uses the magic of ACPI tables
+ * parsing (see drivers/dma/acpi-dma.c for the details) and
+ * matching with the registered General Purpose DMA controllers.
+ */
+ up->dma = dma;
+
+ lpss->dma_maxburst = 16;
+
+ port->set_termios = dw8250_do_set_termios;
+
+ return 0;
+}
+
+static void ehl_serial_exit(struct lpss8250 *lpss)
+{
+ struct uart_8250_port *up = serial8250_get_port(lpss->data.line);
+
+ up->dma = NULL;
+}
+
+#ifdef CONFIG_SERIAL_8250_DMA
+static const struct dw_dma_platform_data qrk_serial_dma_pdata = {
+ .nr_channels = 2,
+ .chan_allocation_order = CHAN_ALLOCATION_ASCENDING,
+ .chan_priority = CHAN_PRIORITY_ASCENDING,
+ .block_size = 4095,
+ .nr_masters = 1,
+ .data_width = {4},
+ .multi_block = {0},
+};
+
+static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
+{
+ struct uart_8250_dma *dma = &lpss->data.dma;
+ struct dw_dma_chip *chip = &lpss->dma_chip;
+ struct dw_dma_slave *param = &lpss->dma_param;
+ struct pci_dev *pdev = to_pci_dev(port->dev);
+ int ret;
+
+ chip->pdata = &qrk_serial_dma_pdata;
+ chip->dev = &pdev->dev;
+ chip->id = pdev->devfn;
+ chip->irq = pci_irq_vector(pdev, 0);
+ chip->regs = pci_ioremap_bar(pdev, 1);
+ if (!chip->regs)
+ return;
+
+ /* Falling back to PIO mode if DMA probing fails */
+ ret = dw_dma_probe(chip);
+ if (ret)
+ return;
+
+ pci_try_set_mwi(pdev);
+
+ /* Special DMA address for UART */
+ dma->rx_dma_addr = 0xfffff000;
+ dma->tx_dma_addr = 0xfffff000;
+
+ param->dma_dev = &pdev->dev;
+ param->src_id = 0;
+ param->dst_id = 1;
+ param->hs_polarity = true;
+
+ lpss->dma_maxburst = 8;
+}
+
+static void qrk_serial_exit_dma(struct lpss8250 *lpss)
+{
+ struct dw_dma_chip *chip = &lpss->dma_chip;
+ struct dw_dma_slave *param = &lpss->dma_param;
+
+ if (!param->dma_dev)
+ return;
+
+ dw_dma_remove(chip);
+
+ pci_iounmap(to_pci_dev(chip->dev), chip->regs);
+}
+#else /* CONFIG_SERIAL_8250_DMA */
+static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port) {}
+static void qrk_serial_exit_dma(struct lpss8250 *lpss) {}
+#endif /* !CONFIG_SERIAL_8250_DMA */
+
+static int qrk_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
+{
+ qrk_serial_setup_dma(lpss, port);
+ return 0;
+}
+
+static void qrk_serial_exit(struct lpss8250 *lpss)
+{
+ qrk_serial_exit_dma(lpss);
+}
+
+static bool lpss8250_dma_filter(struct dma_chan *chan, void *param)
+{
+ struct dw_dma_slave *dws = param;
+
+ if (dws->dma_dev != chan->device->dev)
+ return false;
+
+ chan->private = dws;
+ return true;
+}
+
+static int lpss8250_dma_setup(struct lpss8250 *lpss, struct uart_8250_port *port)
+{
+ struct uart_8250_dma *dma = &lpss->data.dma;
+ struct dw_dma_slave *rx_param, *tx_param;
+ struct device *dev = port->port.dev;
+
+ if (!lpss->dma_param.dma_dev) {
+ dma = port->dma;
+ if (dma)
+ goto out_configuration_only;
+
+ return 0;
+ }
+
+ 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 = lpss->dma_param;
+ *tx_param = lpss->dma_param;
+
+ dma->fn = lpss8250_dma_filter;
+ dma->rx_param = rx_param;
+ dma->tx_param = tx_param;
+
+ port->dma = dma;
+
+out_configuration_only:
+ dma->rxconf.src_maxburst = lpss->dma_maxburst;
+ dma->txconf.dst_maxburst = lpss->dma_maxburst;
+
+ return 0;
+}
+
+static int lpss8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+ struct uart_8250_port uart;
+ struct lpss8250 *lpss;
+ int ret;
+
+ ret = pcim_enable_device(pdev);
+ if (ret)
+ return ret;
+
+ pci_set_master(pdev);
+
+ lpss = devm_kzalloc(&pdev->dev, sizeof(*lpss), GFP_KERNEL);
+ if (!lpss)
+ return -ENOMEM;
+
+ ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
+ if (ret < 0)
+ return ret;
+
+ lpss->board = (struct lpss8250_board *)id->driver_data;
+
+ memset(&uart, 0, sizeof(struct uart_8250_port));
+
+ uart.port.dev = &pdev->dev;
+ uart.port.irq = pci_irq_vector(pdev, 0);
+ uart.port.private_data = &lpss->data;
+ uart.port.type = PORT_16550A;
+ uart.port.iotype = UPIO_MEM32;
+ uart.port.regshift = 2;
+ uart.port.uartclk = lpss->board->base_baud * 16;
+ uart.port.flags = UPF_SHARE_IRQ | UPF_FIXED_PORT | UPF_FIXED_TYPE;
+ uart.capabilities = UART_CAP_FIFO | UART_CAP_AFE;
+ uart.port.mapbase = pci_resource_start(pdev, 0);
+ uart.port.membase = pcim_iomap(pdev, 0, 0);
+ if (!uart.port.membase)
+ return -ENOMEM;
+
+ ret = lpss->board->setup(lpss, &uart.port);
+ if (ret)
+ return ret;
+
+ dw8250_setup_port(&uart.port);
+
+ ret = lpss8250_dma_setup(lpss, &uart);
+ if (ret)
+ goto err_exit;
+
+ ret = serial8250_register_8250_port(&uart);
+ if (ret < 0)
+ goto err_exit;
+
+ lpss->data.line = ret;
+
+ pci_set_drvdata(pdev, lpss);
+ return 0;
+
+err_exit:
+ lpss->board->exit(lpss);
+ pci_free_irq_vectors(pdev);
+ return ret;
+}
+
+static void lpss8250_remove(struct pci_dev *pdev)
+{
+ struct lpss8250 *lpss = pci_get_drvdata(pdev);
+
+ serial8250_unregister_port(lpss->data.line);
+
+ lpss->board->exit(lpss);
+ pci_free_irq_vectors(pdev);
+}
+
+static const struct lpss8250_board byt_board = {
+ .freq = 100000000,
+ .base_baud = 2764800,
+ .setup = byt_serial_setup,
+ .exit = byt_serial_exit,
+};
+
+static const struct lpss8250_board ehl_board = {
+ .freq = 200000000,
+ .base_baud = 12500000,
+ .setup = ehl_serial_setup,
+ .exit = ehl_serial_exit,
+};
+
+static const struct lpss8250_board qrk_board = {
+ .freq = 44236800,
+ .base_baud = 2764800,
+ .setup = qrk_serial_setup,
+ .exit = qrk_serial_exit,
+};
+
+static const struct pci_device_id pci_ids[] = {
+ { PCI_DEVICE_DATA(INTEL, QRK_UARTx, &qrk_board) },
+ { PCI_DEVICE_DATA(INTEL, EHL_UART0, &ehl_board) },
+ { PCI_DEVICE_DATA(INTEL, EHL_UART1, &ehl_board) },
+ { PCI_DEVICE_DATA(INTEL, EHL_UART2, &ehl_board) },
+ { PCI_DEVICE_DATA(INTEL, EHL_UART3, &ehl_board) },
+ { PCI_DEVICE_DATA(INTEL, EHL_UART4, &ehl_board) },
+ { PCI_DEVICE_DATA(INTEL, EHL_UART5, &ehl_board) },
+ { PCI_DEVICE_DATA(INTEL, BYT_UART1, &byt_board) },
+ { PCI_DEVICE_DATA(INTEL, BYT_UART2, &byt_board) },
+ { PCI_DEVICE_DATA(INTEL, BSW_UART1, &byt_board) },
+ { PCI_DEVICE_DATA(INTEL, BSW_UART2, &byt_board) },
+ { PCI_DEVICE_DATA(INTEL, BDW_UART1, &byt_board) },
+ { PCI_DEVICE_DATA(INTEL, BDW_UART2, &byt_board) },
+ { }
+};
+MODULE_DEVICE_TABLE(pci, pci_ids);
+
+static struct pci_driver lpss8250_pci_driver = {
+ .name = "8250_lpss",
+ .id_table = pci_ids,
+ .probe = lpss8250_probe,
+ .remove = lpss8250_remove,
+};
+
+module_pci_driver(lpss8250_pci_driver);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Intel LPSS UART driver");