diff options
Diffstat (limited to 'arch/powerpc/boot/cpm-serial.c')
| -rw-r--r-- | arch/powerpc/boot/cpm-serial.c | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/arch/powerpc/boot/cpm-serial.c b/arch/powerpc/boot/cpm-serial.c new file mode 100644 index 0000000000..dfb56829ca --- /dev/null +++ b/arch/powerpc/boot/cpm-serial.c @@ -0,0 +1,295 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * CPM serial console support. + * + * Copyright 2007 Freescale Semiconductor, Inc. + * Author: Scott Wood <scottwood@freescale.com> + * + * It is assumed that the firmware (or the platform file) has already set + * up the port. + */ + +#include "types.h" +#include "io.h" +#include "ops.h" +#include "page.h" + +struct cpm_scc { + u32 gsmrl; + u32 gsmrh; + u16 psmr; + u8 res1[2]; + u16 todr; + u16 dsr; + u16 scce; + u8 res2[2]; + u16 sccm; + u8 res3; + u8 sccs; + u8 res4[8]; +}; + +struct cpm_smc { + u8 res1[2]; + u16 smcmr; + u8 res2[2]; + u8 smce; + u8 res3[3]; + u8 smcm; + u8 res4[5]; +}; + +struct cpm_param { + u16 rbase; + u16 tbase; + u8 rfcr; + u8 tfcr; + u16 mrblr; + u32 rstate; + u8 res1[4]; + u16 rbptr; + u8 res2[6]; + u32 tstate; + u8 res3[4]; + u16 tbptr; + u8 res4[6]; + u16 maxidl; + u16 idlc; + u16 brkln; + u16 brkec; + u16 brkcr; + u16 rmask; + u8 res5[4]; +}; + +struct cpm_bd { + u16 sc; /* Status and Control */ + u16 len; /* Data length in buffer */ + u8 *addr; /* Buffer address in host memory */ +}; + +static void *cpcr; +static struct cpm_param *param; +static struct cpm_smc *smc; +static struct cpm_scc *scc; +static struct cpm_bd *tbdf, *rbdf; +static u32 cpm_cmd; +static void *cbd_addr; +static u32 cbd_offset; + +static void (*do_cmd)(int op); +static void (*enable_port)(void); +static void (*disable_port)(void); + +#define CPM_CMD_STOP_TX 4 +#define CPM_CMD_RESTART_TX 6 +#define CPM_CMD_INIT_RX_TX 0 + +static void cpm1_cmd(int op) +{ + while (in_be16(cpcr) & 1) + ; + + out_be16(cpcr, (op << 8) | cpm_cmd | 1); + + while (in_be16(cpcr) & 1) + ; +} + +static void cpm2_cmd(int op) +{ + while (in_be32(cpcr) & 0x10000) + ; + + out_be32(cpcr, op | cpm_cmd | 0x10000); + + while (in_be32(cpcr) & 0x10000) + ; +} + +static void smc_disable_port(void) +{ + do_cmd(CPM_CMD_STOP_TX); + out_be16(&smc->smcmr, in_be16(&smc->smcmr) & ~3); +} + +static void scc_disable_port(void) +{ + do_cmd(CPM_CMD_STOP_TX); + out_be32(&scc->gsmrl, in_be32(&scc->gsmrl) & ~0x30); +} + +static void smc_enable_port(void) +{ + out_be16(&smc->smcmr, in_be16(&smc->smcmr) | 3); + do_cmd(CPM_CMD_RESTART_TX); +} + +static void scc_enable_port(void) +{ + out_be32(&scc->gsmrl, in_be32(&scc->gsmrl) | 0x30); + do_cmd(CPM_CMD_RESTART_TX); +} + +static int cpm_serial_open(void) +{ + disable_port(); + + out_8(¶m->rfcr, 0x10); + out_8(¶m->tfcr, 0x10); + out_be16(¶m->mrblr, 1); + out_be16(¶m->maxidl, 0); + out_be16(¶m->brkec, 0); + out_be16(¶m->brkln, 0); + out_be16(¶m->brkcr, 0); + + rbdf = cbd_addr; + rbdf->addr = (u8 *)rbdf - 1; + rbdf->sc = 0xa000; + rbdf->len = 1; + + tbdf = rbdf + 1; + tbdf->addr = (u8 *)rbdf - 2; + tbdf->sc = 0x2000; + tbdf->len = 1; + + sync(); + out_be16(¶m->rbase, cbd_offset); + out_be16(¶m->tbase, cbd_offset + sizeof(struct cpm_bd)); + + do_cmd(CPM_CMD_INIT_RX_TX); + + enable_port(); + return 0; +} + +static void cpm_serial_putc(unsigned char c) +{ + while (tbdf->sc & 0x8000) + barrier(); + + sync(); + + tbdf->addr[0] = c; + eieio(); + tbdf->sc |= 0x8000; +} + +static unsigned char cpm_serial_tstc(void) +{ + barrier(); + return !(rbdf->sc & 0x8000); +} + +static unsigned char cpm_serial_getc(void) +{ + unsigned char c; + + while (!cpm_serial_tstc()) + ; + + sync(); + c = rbdf->addr[0]; + eieio(); + rbdf->sc |= 0x8000; + + return c; +} + +int cpm_console_init(void *devp, struct serial_console_data *scdp) +{ + void *vreg[2]; + u32 reg[2]; + int is_smc = 0, is_cpm2 = 0; + void *parent, *muram; + void *muram_addr; + unsigned long muram_offset, muram_size; + + if (dt_is_compatible(devp, "fsl,cpm1-smc-uart")) { + is_smc = 1; + } else if (dt_is_compatible(devp, "fsl,cpm2-scc-uart")) { + is_cpm2 = 1; + } else if (dt_is_compatible(devp, "fsl,cpm2-smc-uart")) { + is_cpm2 = 1; + is_smc = 1; + } + + if (is_smc) { + enable_port = smc_enable_port; + disable_port = smc_disable_port; + } else { + enable_port = scc_enable_port; + disable_port = scc_disable_port; + } + + if (is_cpm2) + do_cmd = cpm2_cmd; + else + do_cmd = cpm1_cmd; + + if (getprop(devp, "fsl,cpm-command", &cpm_cmd, 4) < 4) + return -1; + + if (dt_get_virtual_reg(devp, vreg, 2) < 2) + return -1; + + if (is_smc) + smc = vreg[0]; + else + scc = vreg[0]; + + param = vreg[1]; + + parent = get_parent(devp); + if (!parent) + return -1; + + if (dt_get_virtual_reg(parent, &cpcr, 1) < 1) + return -1; + + muram = finddevice("/soc/cpm/muram/data"); + if (!muram) + return -1; + + /* For bootwrapper-compatible device trees, we assume that the first + * entry has at least 128 bytes, and that #address-cells/#data-cells + * is one for both parent and child. + */ + + if (dt_get_virtual_reg(muram, &muram_addr, 1) < 1) + return -1; + + if (getprop(muram, "reg", reg, 8) < 8) + return -1; + + muram_offset = reg[0]; + muram_size = reg[1]; + + /* Store the buffer descriptors at the end of the first muram chunk. + * For SMC ports on CPM2-based platforms, relocate the parameter RAM + * just before the buffer descriptors. + */ + + cbd_offset = muram_offset + muram_size - 2 * sizeof(struct cpm_bd); + + if (is_cpm2 && is_smc) { + u16 *smc_base = (u16 *)param; + u16 pram_offset; + + pram_offset = cbd_offset - 64; + pram_offset = _ALIGN_DOWN(pram_offset, 64); + + disable_port(); + out_be16(smc_base, pram_offset); + param = muram_addr - muram_offset + pram_offset; + } + + cbd_addr = muram_addr - muram_offset + cbd_offset; + + scdp->open = cpm_serial_open; + scdp->putc = cpm_serial_putc; + scdp->getc = cpm_serial_getc; + scdp->tstc = cpm_serial_tstc; + + return 0; +} |