serial/cpm_uart/cpm_uart_cpm2.c

0001 // SPDX-License-Identifier: GPL-2.0+
0002 /*
0003  *  Driver for CPM (SCC/SMC) serial ports; CPM2 definitions
0004  *
0005  *  Maintainer: Kumar Gala (galak@kernel.crashing.org) (CPM2)
0006  *              Pantelis Antoniou (panto@intracom.gr) (CPM1)
0007  *
0008  *  Copyright (C) 2004 Freescale Semiconductor, Inc.
0009  *            (C) 2004 Intracom, S.A.
0010  *            (C) 2006 MontaVista Software, Inc.
0011  *      Vitaly Bordug <vbordug@ru.mvista.com>
0012  */
0013
0014 #include <linux/module.h>
0015 #include <linux/tty.h>
0016 #include <linux/ioport.h>
0017 #include <linux/slab.h>
0018 #include <linux/serial.h>
0019 #include <linux/console.h>
0020 #include <linux/sysrq.h>
0021 #include <linux/device.h>
0022 #include <linux/memblock.h>
0023 #include <linux/dma-mapping.h>
0024
0025 #include <asm/io.h>
0026 #include <asm/irq.h>
0027 #include <asm/fs_pd.h>
0028
0029 #include <linux/serial_core.h>
0030 #include <linux/kernel.h>
0031
0032 #include "cpm_uart.h"
0033
0034 /**************************************************************/
0035
0036 void cpm_line_cr_cmd(struct uart_cpm_port *port, int cmd)
0037 {
0038     cpm_command(port->command, cmd);
0039 }
0040
0041 void __iomem *cpm_uart_map_pram(struct uart_cpm_port *port,
0042                 struct device_node *np)
0043 {
0044     void __iomem *pram;
0045     unsigned long offset;
0046     struct resource res;
0047     resource_size_t len;
0048
0049     /* Don't remap parameter RAM if it has already been initialized
0050      * during console setup.
0051      */
0052     if (IS_SMC(port) && port->smcup)
0053         return port->smcup;
0054     else if (!IS_SMC(port) && port->sccup)
0055         return port->sccup;
0056
0057     if (of_address_to_resource(np, 1, &res))
0058         return NULL;
0059
0060     len = resource_size(&res);
0061     pram = ioremap(res.start, len);
0062     if (!pram)
0063         return NULL;
0064
0065     if (!IS_SMC(port))
0066         return pram;
0067
0068     if (len != 2) {
0069         printk(KERN_WARNING "cpm_uart[%d]: device tree references "
0070             "SMC pram, using boot loader/wrapper pram mapping. "
0071             "Please fix your device tree to reference the pram "
0072             "base register instead.\n",
0073             port->port.line);
0074         return pram;
0075     }
0076
0077     offset = cpm_dpalloc(PROFF_SMC_SIZE, 64);
0078     out_be16(pram, offset);
0079     iounmap(pram);
0080     return cpm_muram_addr(offset);
0081 }
0082
0083 void cpm_uart_unmap_pram(struct uart_cpm_port *port, void __iomem *pram)
0084 {
0085     if (!IS_SMC(port))
0086         iounmap(pram);
0087 }
0088
0089 /*
0090  * Allocate DP-Ram and memory buffers. We need to allocate a transmit and
0091  * receive buffer descriptors from dual port ram, and a character
0092  * buffer area from host mem. If we are allocating for the console we need
0093  * to do it from bootmem
0094  */
0095 int cpm_uart_allocbuf(struct uart_cpm_port *pinfo, unsigned int is_con)
0096 {
0097     int dpmemsz, memsz;
0098     u8 __iomem *dp_mem;
0099     unsigned long dp_offset;
0100     u8 *mem_addr;
0101     dma_addr_t dma_addr = 0;
0102
0103     pr_debug("CPM uart[%d]:allocbuf\n", pinfo->port.line);
0104
0105     dpmemsz = sizeof(cbd_t) * (pinfo->rx_nrfifos + pinfo->tx_nrfifos);
0106     dp_offset = cpm_dpalloc(dpmemsz, 8);
0107     if (IS_ERR_VALUE(dp_offset)) {
0108         printk(KERN_ERR
0109                "cpm_uart_cpm.c: could not allocate buffer descriptors\n");
0110         return -ENOMEM;
0111     }
0112
0113     dp_mem = cpm_dpram_addr(dp_offset);
0114
0115     memsz = L1_CACHE_ALIGN(pinfo->rx_nrfifos * pinfo->rx_fifosize) +
0116         L1_CACHE_ALIGN(pinfo->tx_nrfifos * pinfo->tx_fifosize);
0117     if (is_con) {
0118         mem_addr = kzalloc(memsz, GFP_NOWAIT);
0119         dma_addr = virt_to_bus(mem_addr);
0120     }
0121     else
0122         mem_addr = dma_alloc_coherent(pinfo->port.dev, memsz, &dma_addr,
0123                           GFP_KERNEL);
0124
0125     if (mem_addr == NULL) {
0126         cpm_dpfree(dp_offset);
0127         printk(KERN_ERR
0128                "cpm_uart_cpm.c: could not allocate coherent memory\n");
0129         return -ENOMEM;
0130     }
0131
0132     pinfo->dp_addr = dp_offset;
0133     pinfo->mem_addr = mem_addr;
0134     pinfo->dma_addr = dma_addr;
0135     pinfo->mem_size = memsz;
0136
0137     pinfo->rx_buf = mem_addr;
0138     pinfo->tx_buf = pinfo->rx_buf + L1_CACHE_ALIGN(pinfo->rx_nrfifos
0139                                * pinfo->rx_fifosize);
0140
0141     pinfo->rx_bd_base = (cbd_t __iomem *)dp_mem;
0142     pinfo->tx_bd_base = pinfo->rx_bd_base + pinfo->rx_nrfifos;
0143
0144     return 0;
0145 }
0146
0147 void cpm_uart_freebuf(struct uart_cpm_port *pinfo)
0148 {
0149     dma_free_coherent(pinfo->port.dev, L1_CACHE_ALIGN(pinfo->rx_nrfifos *
0150                               pinfo->rx_fifosize) +
0151               L1_CACHE_ALIGN(pinfo->tx_nrfifos *
0152                      pinfo->tx_fifosize), (void __force *)pinfo->mem_addr,
0153               pinfo->dma_addr);
0154
0155     cpm_dpfree(pinfo->dp_addr);
0156 }