// SPDX-License-Identifier: GPL-2.0-or-later /* * Freescale CPM1/CPM2 I2C interface. * Copyright (c) 1999 Dan Malek (dmalek@jlc.net). * * moved into proper i2c interface; * Brad Parker (brad@heeltoe.com) * * Parts from dbox2_i2c.c (cvs.tuxbox.org) * (C) 2000-2001 Felix Domke (tmbinc@gmx.net), Gillem (htoa@gmx.net) * * (C) 2007 Montavista Software, Inc. * Vitaly Bordug <vitb@kernel.crashing.org> * * Converted to of_platform_device. Renamed to i2c-cpm.c. * (C) 2007,2008 Jochen Friedrich <jochen@scram.de> */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/delay.h> #include <linux/slab.h> #include <linux/interrupt.h> #include <linux/errno.h> #include <linux/stddef.h> #include <linux/i2c.h> #include <linux/io.h> #include <linux/dma-mapping.h> #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_irq.h> #include <linux/platform_device.h> #include <sysdev/fsl_soc.h> #include <asm/cpm.h> /* Try to define this if you have an older CPU (earlier than rev D4) */ /* However, better use a GPIO based bitbang driver in this case :/ */ #undef I2C_CHIP_ERRATA #define CPM_MAX_READ 513 #define CPM_MAXBD 4 #define I2C_EB (0x10) /* Big endian mode */ #define I2C_EB_CPM2 (0x30) /* Big endian mode, memory snoop */ #define DPRAM_BASE ((u8 __iomem __force *)cpm_muram_addr(0)) /* I2C parameter RAM. */ struct i2c_ram { ushort rbase; /* Rx Buffer descriptor base address */ ushort tbase; /* Tx Buffer descriptor base address */ u_char rfcr; /* Rx function code */ u_char tfcr; /* Tx function code */ ushort mrblr; /* Max receive buffer length */ uint rstate; /* Internal */ uint rdp; /* Internal */ ushort rbptr; /* Rx Buffer descriptor pointer */ ushort rbc; /* Internal */ uint rxtmp; /* Internal */ uint tstate; /* Internal */ uint tdp; /* Internal */ ushort tbptr; /* Tx Buffer descriptor pointer */ ushort tbc; /* Internal */ uint txtmp; /* Internal */ char res1[4]; /* Reserved */ ushort rpbase; /* Relocation pointer */ char res2[2]; /* Reserved */ /* The following elements are only for CPM2 */ char res3[4]; /* Reserved */ uint sdmatmp; /* Internal */ }; #define I2COM_START 0x80 #define I2COM_MASTER 0x01 #define I2CER_TXE 0x10 #define I2CER_BUSY 0x04 #define I2CER_TXB 0x02 #define I2CER_RXB 0x01 #define I2MOD_EN 0x01 /* I2C Registers */ struct i2c_reg { u8 i2mod; u8 res1[3]; u8 i2add; u8 res2[3]; u8 i2brg; u8 res3[3]; u8 i2com; u8 res4[3]; u8 i2cer; u8 res5[3]; u8 i2cmr; }; struct cpm_i2c { char *base; struct platform_device *ofdev; struct i2c_adapter adap; uint dp_addr; int version; /* CPM1=1, CPM2=2 */ int irq; int cp_command; int freq; struct i2c_reg __iomem *i2c_reg; struct i2c_ram __iomem *i2c_ram; u16 i2c_addr; wait_queue_head_t i2c_wait; cbd_t __iomem *tbase; cbd_t __iomem *rbase; u_char *txbuf[CPM_MAXBD]; u_char *rxbuf[CPM_MAXBD]; dma_addr_t txdma[CPM_MAXBD]; dma_addr_t rxdma[CPM_MAXBD]; }; static irqreturn_t cpm_i2c_interrupt(int irq, void *dev_id) { struct cpm_i2c *cpm; struct i2c_reg __iomem *i2c_reg; struct i2c_adapter *adap = dev_id; int i; cpm = i2c_get_adapdata(dev_id); i2c_reg = cpm->i2c_reg; /* Clear interrupt. */ i = in_8(&i2c_reg->i2cer); out_8(&i2c_reg->i2cer, i); dev_dbg(&adap->dev, "Interrupt: %x\n", i); wake_up(&cpm->i2c_wait); return i ? IRQ_HANDLED : IRQ_NONE; } static void cpm_reset_i2c_params(struct cpm_i2c *cpm) { struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram; /* Set up the I2C parameters in the parameter ram. */ out_be16(&i2c_ram->tbase, (u8 __iomem *)cpm->tbase - DPRAM_BASE); out_be16(&i2c_ram->rbase, (u8 __iomem *)cpm->rbase - DPRAM_BASE); if (cpm->version == 1) { out_8(&i2c_ram->tfcr, I2C_EB); out_8(&i2c_ram->rfcr, I2C_EB); } else { out_8(&i2c_ram->tfcr, I2C_EB_CPM2); out_8(&i2c_ram->rfcr, I2C_EB_CPM2); } out_be16(&i2c_ram->mrblr, CPM_MAX_READ); out_be32(&i2c_ram->rstate, 0); out_be32(&i2c_ram->rdp, 0); out_be16(&i2c_ram->rbptr, 0); out_be16(&i2c_ram->rbc, 0); out_be32(&i2c_ram->rxtmp, 0); out_be32(&i2c_ram->tstate, 0); out_be32(&i2c_ram->tdp, 0); out_be16(&i2c_ram->tbptr, 0); out_be16(&i2c_ram->tbc, 0); out_be32(&i2c_ram->txtmp, 0); } static void cpm_i2c_force_close(struct i2c_adapter *adap) { struct cpm_i2c *cpm = i2c_get_adapdata(adap); struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg; dev_dbg(&adap->dev, "cpm_i2c_force_close()\n"); cpm_command(cpm->cp_command, CPM_CR_CLOSE_RX_BD); out_8(&i2c_reg->i2cmr, 0x00); /* Disable all interrupts */ out_8(&i2c_reg->i2cer, 0xff); } static void cpm_i2c_parse_message(struct i2c_adapter *adap, struct i2c_msg *pmsg, int num, int tx, int rx) { cbd_t __iomem *tbdf; cbd_t __iomem *rbdf; u_char addr; u_char *tb; u_char *rb; struct cpm_i2c *cpm = i2c_get_adapdata(adap); tbdf = cpm->tbase + tx; rbdf = cpm->rbase + rx; addr = i2c_8bit_addr_from_msg(pmsg); tb = cpm->txbuf[tx]; rb = cpm->rxbuf[rx]; /* Align read buffer */ rb = (u_char *) (((ulong) rb + 1) & ~1); tb[0] = addr; /* Device address byte w/rw flag */ out_be16(&tbdf->cbd_datlen, pmsg->len + 1); out_be16(&tbdf->cbd_sc, 0); if (!(pmsg->flags & I2C_M_NOSTART)) setbits16(&tbdf->cbd_sc, BD_I2C_START); if (tx + 1 == num) setbits16(&tbdf->cbd_sc, BD_SC_LAST | BD_SC_WRAP); if (pmsg->flags & I2C_M_RD) { /* * To read, we need an empty buffer of the proper length. * All that is used is the first byte for address, the remainder * is just used for timing (and doesn't really have to exist). */ dev_dbg(&adap->dev, "cpm_i2c_read(abyte=0x%x)\n", addr); out_be16(&rbdf->cbd_datlen, 0); out_be16(&rbdf->cbd_sc, BD_SC_EMPTY | BD_SC_INTRPT); if (rx + 1 == CPM_MAXBD) setbits16(&rbdf->cbd_sc, BD_SC_WRAP); eieio(); setbits16(&tbdf->cbd_sc, BD_SC_READY); } else { dev_dbg(&adap->dev, "cpm_i2c_write(abyte=0x%x)\n", addr); memcpy(tb+1, pmsg->buf, pmsg->len); eieio(); setbits16(&tbdf->cbd_sc, BD_SC_READY | BD_SC_INTRPT); } } static int cpm_i2c_check_message(struct i2c_adapter *adap, struct i2c_msg *pmsg, int tx, int rx) { cbd_t __iomem *tbdf; cbd_t __iomem *rbdf; u_char *tb; u_char *rb; struct cpm_i2c *cpm = i2c_get_adapdata(adap); tbdf = cpm->tbase + tx; rbdf = cpm->rbase + rx; tb = cpm->txbuf[tx]; rb = cpm->rxbuf[rx]; /* Align read buffer */ rb = (u_char *) (((uint) rb + 1) & ~1); eieio(); if (pmsg->flags & I2C_M_RD) { dev_dbg(&adap->dev, "tx sc 0x%04x, rx sc 0x%04x\n", in_be16(&tbdf->cbd_sc), in_be16(&rbdf->cbd_sc)); if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) { dev_dbg(&adap->dev, "I2C read; No ack\n"); return -ENXIO; } if (in_be16(&rbdf->cbd_sc) & BD_SC_EMPTY) { dev_err(&adap->dev, "I2C read; complete but rbuf empty\n"); return -EREMOTEIO; } if (in_be16(&rbdf->cbd_sc) & BD_SC_OV) { dev_err(&adap->dev, "I2C read; Overrun\n"); return -EREMOTEIO; } memcpy(pmsg->buf, rb, pmsg->len); } else { dev_dbg(&adap->dev, "tx sc %d 0x%04x\n", tx, in_be16(&tbdf->cbd_sc)); if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) { dev_dbg(&adap->dev, "I2C write; No ack\n"); return -ENXIO; } if (in_be16(&tbdf->cbd_sc) & BD_SC_UN) { dev_err(&adap->dev, "I2C write; Underrun\n"); return -EIO; } if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) { dev_err(&adap->dev, "I2C write; Collision\n"); return -EIO; } } return 0; } static int cpm_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) { struct cpm_i2c *cpm = i2c_get_adapdata(adap); struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg; struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram; struct i2c_msg *pmsg; int ret; int tptr; int rptr; cbd_t __iomem *tbdf; cbd_t __iomem *rbdf; /* Reset to use first buffer */ out_be16(&i2c_ram->rbptr, in_be16(&i2c_ram->rbase)); out_be16(&i2c_ram->tbptr, in_be16(&i2c_ram->tbase)); tbdf = cpm->tbase; rbdf = cpm->rbase; tptr = 0; rptr = 0; /* * If there was a collision in the last i2c transaction, * Set I2COM_MASTER as it was cleared during collision. */ if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) { out_8(&cpm->i2c_reg->i2com, I2COM_MASTER); } while (tptr < num) { pmsg = &msgs[tptr]; dev_dbg(&adap->dev, "R: %d T: %d\n", rptr, tptr); cpm_i2c_parse_message(adap, pmsg, num, tptr, rptr); if (pmsg->flags & I2C_M_RD) rptr++; tptr++; } /* Start transfer now */ /* Enable RX/TX/Error interupts */ out_8(&i2c_reg->i2cmr, I2CER_TXE | I2CER_TXB | I2CER_RXB); out_8(&i2c_reg->i2cer, 0xff); /* Clear interrupt status */ /* Chip bug, set enable here */ setbits8(&i2c_reg->i2mod, I2MOD_EN); /* Enable */ /* Begin transmission */ setbits8(&i2c_reg->i2com, I2COM_START); tptr = 0; rptr = 0; while (tptr < num) { /* Check for outstanding messages */ dev_dbg(&adap->dev, "test ready.\n"); pmsg = &msgs[tptr]; if (pmsg->flags & I2C_M_RD) ret = wait_event_timeout(cpm->i2c_wait, (in_be16(&tbdf[tptr].cbd_sc) & BD_SC_NAK) || !(in_be16(&rbdf[rptr].cbd_sc) & BD_SC_EMPTY), 1 * HZ); else ret = wait_event_timeout(cpm->i2c_wait, !(in_be16(&tbdf[tptr].cbd_sc) & BD_SC_READY), 1 * HZ); if (ret == 0) { ret = -EREMOTEIO; dev_err(&adap->dev, "I2C transfer: timeout\n"); goto out_err; } if (ret > 0) { dev_dbg(&adap->dev, "ready.\n"); ret = cpm_i2c_check_message(adap, pmsg, tptr, rptr); tptr++; if (pmsg->flags & I2C_M_RD) rptr++; if (ret) goto out_err; } } #ifdef I2C_CHIP_ERRATA /* * Chip errata, clear enable. This is not needed on rev D4 CPUs. * Disabling I2C too early may cause too short stop condition */ udelay(4); clrbits8(&i2c_reg->i2mod, I2MOD_EN); #endif return (num); out_err: cpm_i2c_force_close(adap); #ifdef I2C_CHIP_ERRATA /* * Chip errata, clear enable. This is not needed on rev D4 CPUs. */ clrbits8(&i2c_reg->i2mod, I2MOD_EN); #endif return ret; } static u32 cpm_i2c_func(struct i2c_adapter *adap) { return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK); } /* -----exported algorithm data: ------------------------------------- */ static const struct i2c_algorithm cpm_i2c_algo = { .master_xfer = cpm_i2c_xfer, .functionality = cpm_i2c_func, }; /* CPM_MAX_READ is also limiting writes according to the code! */ static const struct i2c_adapter_quirks cpm_i2c_quirks = { .max_num_msgs = CPM_MAXBD, .max_read_len = CPM_MAX_READ, .max_write_len = CPM_MAX_READ, }; static const struct i2c_adapter cpm_ops = { .owner = THIS_MODULE, .name = "i2c-cpm", .algo = &cpm_i2c_algo, .quirks = &cpm_i2c_quirks, }; static int cpm_i2c_setup(struct cpm_i2c *cpm) { struct platform_device *ofdev = cpm->ofdev; const u32 *data; int len, ret, i; void __iomem *i2c_base; cbd_t __iomem *tbdf; cbd_t __iomem *rbdf; unsigned char brg; dev_dbg(&cpm->ofdev->dev, "cpm_i2c_setup()\n"); init_waitqueue_head(&cpm->i2c_wait); cpm->irq = irq_of_parse_and_map(ofdev->dev.of_node, 0); if (!cpm->irq) return -EINVAL; /* Install interrupt handler. */ ret = request_irq(cpm->irq, cpm_i2c_interrupt, 0, "cpm_i2c", &cpm->adap); if (ret) return ret; /* I2C parameter RAM */ i2c_base = of_iomap(ofdev->dev.of_node, 1); if (i2c_base == NULL) { ret = -EINVAL; goto out_irq; } if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm1-i2c")) { /* Check for and use a microcode relocation patch. */ cpm->i2c_ram = i2c_base; cpm->i2c_addr = in_be16(&cpm->i2c_ram->rpbase); /* * Maybe should use cpm_muram_alloc instead of hardcoding * this in micropatch.c */ if (cpm->i2c_addr) { cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr); iounmap(i2c_base); } cpm->version = 1; } else if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm2-i2c")) { cpm->i2c_addr = cpm_muram_alloc(sizeof(struct i2c_ram), 64); cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr); out_be16(i2c_base, cpm->i2c_addr); iounmap(i2c_base); cpm->version = 2; } else { iounmap(i2c_base); ret = -EINVAL; goto out_irq; } /* I2C control/status registers */ cpm->i2c_reg = of_iomap(ofdev->dev.of_node, 0); if (cpm->i2c_reg == NULL) { ret = -EINVAL; goto out_ram; } data = of_get_property(ofdev->dev.of_node, "fsl,cpm-command", &len); if (!data || len != 4) { ret = -EINVAL; goto out_reg; } cpm->cp_command = *data; data = of_get_property(ofdev->dev.of_node, "linux,i2c-class", &len); if (data && len == 4) cpm->adap.class = *data; data = of_get_property(ofdev->dev.of_node, "clock-frequency", &len); if (data && len == 4) cpm->freq = *data; else cpm->freq = 60000; /* use 60kHz i2c clock by default */ /* * Allocate space for CPM_MAXBD transmit and receive buffer * descriptors in the DP ram. */ cpm->dp_addr = cpm_muram_alloc(sizeof(cbd_t) * 2 * CPM_MAXBD, 8); if (!cpm->dp_addr) { ret = -ENOMEM; goto out_reg; } cpm->tbase = cpm_muram_addr(cpm->dp_addr); cpm->rbase = cpm_muram_addr(cpm->dp_addr + sizeof(cbd_t) * CPM_MAXBD); /* Allocate TX and RX buffers */ tbdf = cpm->tbase; rbdf = cpm->rbase; for (i = 0; i < CPM_MAXBD; i++) { cpm->rxbuf[i] = dma_alloc_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1, &cpm->rxdma[i], GFP_KERNEL); if (!cpm->rxbuf[i]) { ret = -ENOMEM; goto out_muram; } out_be32(&rbdf[i].cbd_bufaddr, ((cpm->rxdma[i] + 1) & ~1)); cpm->txbuf[i] = dma_alloc_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1, &cpm->txdma[i], GFP_KERNEL); if (!cpm->txbuf[i]) { ret = -ENOMEM; goto out_muram; } out_be32(&tbdf[i].cbd_bufaddr, cpm->txdma[i]); } /* Initialize Tx/Rx parameters. */ cpm_reset_i2c_params(cpm); dev_dbg(&cpm->ofdev->dev, "i2c_ram 0x%p, i2c_addr 0x%04x, freq %d\n", cpm->i2c_ram, cpm->i2c_addr, cpm->freq); dev_dbg(&cpm->ofdev->dev, "tbase 0x%04x, rbase 0x%04x\n", (u8 __iomem *)cpm->tbase - DPRAM_BASE, (u8 __iomem *)cpm->rbase - DPRAM_BASE); cpm_command(cpm->cp_command, CPM_CR_INIT_TRX); /* * Select an invalid address. Just make sure we don't use loopback mode */ out_8(&cpm->i2c_reg->i2add, 0x7f << 1); /* * PDIV is set to 00 in i2mod, so brgclk/32 is used as input to the * i2c baud rate generator. This is divided by 2 x (DIV + 3) to get * the actual i2c bus frequency. */ brg = get_brgfreq() / (32 * 2 * cpm->freq) - 3; out_8(&cpm->i2c_reg->i2brg, brg); out_8(&cpm->i2c_reg->i2mod, 0x00); out_8(&cpm->i2c_reg->i2com, I2COM_MASTER); /* Master mode */ /* Disable interrupts. */ out_8(&cpm->i2c_reg->i2cmr, 0); out_8(&cpm->i2c_reg->i2cer, 0xff); return 0; out_muram: for (i = 0; i < CPM_MAXBD; i++) { if (cpm->rxbuf[i]) dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1, cpm->rxbuf[i], cpm->rxdma[i]); if (cpm->txbuf[i]) dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1, cpm->txbuf[i], cpm->txdma[i]); } cpm_muram_free(cpm->dp_addr); out_reg: iounmap(cpm->i2c_reg); out_ram: if ((cpm->version == 1) && (!cpm->i2c_addr)) iounmap(cpm->i2c_ram); if (cpm->version == 2) cpm_muram_free(cpm->i2c_addr); out_irq: free_irq(cpm->irq, &cpm->adap); return ret; } static void cpm_i2c_shutdown(struct cpm_i2c *cpm) { int i; /* Shut down I2C. */ clrbits8(&cpm->i2c_reg->i2mod, I2MOD_EN); /* Disable interrupts */ out_8(&cpm->i2c_reg->i2cmr, 0); out_8(&cpm->i2c_reg->i2cer, 0xff); free_irq(cpm->irq, &cpm->adap); /* Free all memory */ for (i = 0; i < CPM_MAXBD; i++) { dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1, cpm->rxbuf[i], cpm->rxdma[i]); dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1, cpm->txbuf[i], cpm->txdma[i]); } cpm_muram_free(cpm->dp_addr); iounmap(cpm->i2c_reg); if ((cpm->version == 1) && (!cpm->i2c_addr)) iounmap(cpm->i2c_ram); if (cpm->version == 2) cpm_muram_free(cpm->i2c_addr); } static int cpm_i2c_probe(struct platform_device *ofdev) { int result, len; struct cpm_i2c *cpm; const u32 *data; cpm = kzalloc(sizeof(struct cpm_i2c), GFP_KERNEL); if (!cpm) return -ENOMEM; cpm->ofdev = ofdev; platform_set_drvdata(ofdev, cpm); cpm->adap = cpm_ops; i2c_set_adapdata(&cpm->adap, cpm); cpm->adap.dev.parent = &ofdev->dev; cpm->adap.dev.of_node = of_node_get(ofdev->dev.of_node); result = cpm_i2c_setup(cpm); if (result) { dev_err(&ofdev->dev, "Unable to init hardware\n"); goto out_free; } /* register new adapter to i2c module... */ data = of_get_property(ofdev->dev.of_node, "linux,i2c-index", &len); cpm->adap.nr = (data && len == 4) ? be32_to_cpup(data) : -1; result = i2c_add_numbered_adapter(&cpm->adap); if (result < 0) goto out_shut; dev_dbg(&ofdev->dev, "hw routines for %s registered.\n", cpm->adap.name); return 0; out_shut: cpm_i2c_shutdown(cpm); out_free: kfree(cpm); return result; } static void cpm_i2c_remove(struct platform_device *ofdev) { struct cpm_i2c *cpm = platform_get_drvdata(ofdev); i2c_del_adapter(&cpm->adap); cpm_i2c_shutdown(cpm); kfree(cpm); } static const struct of_device_id cpm_i2c_match[] = { { .compatible = "fsl,cpm1-i2c", }, { .compatible = "fsl,cpm2-i2c", }, {}, }; MODULE_DEVICE_TABLE(of, cpm_i2c_match); static struct platform_driver cpm_i2c_driver = { .probe = cpm_i2c_probe, .remove_new = cpm_i2c_remove, .driver = { .name = "fsl-i2c-cpm", .of_match_table = cpm_i2c_match, }, }; module_platform_driver(cpm_i2c_driver); MODULE_AUTHOR("Jochen Friedrich <jochen@scram.de>"); MODULE_DESCRIPTION("I2C-Bus adapter routines for CPM boards"); MODULE_LICENSE("GPL");