+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) 2014 Uwe Kleine-Koenig for Pengutronix
- */
-#include <linux/module.h>
-#include <linux/platform_device.h>
-#include <linux/i2c.h>
-#include <linux/io.h>
-#include <linux/interrupt.h>
-#include <linux/err.h>
-#include <linux/clk.h>
-
-#define DRIVER_NAME "efm32-i2c"
-
-#define MASK_VAL(mask, val) ((val << __ffs(mask)) & mask)
-
-#define REG_CTRL 0x00
-#define REG_CTRL_EN 0x00001
-#define REG_CTRL_SLAVE 0x00002
-#define REG_CTRL_AUTOACK 0x00004
-#define REG_CTRL_AUTOSE 0x00008
-#define REG_CTRL_AUTOSN 0x00010
-#define REG_CTRL_ARBDIS 0x00020
-#define REG_CTRL_GCAMEN 0x00040
-#define REG_CTRL_CLHR__MASK 0x00300
-#define REG_CTRL_BITO__MASK 0x03000
-#define REG_CTRL_BITO_OFF 0x00000
-#define REG_CTRL_BITO_40PCC 0x01000
-#define REG_CTRL_BITO_80PCC 0x02000
-#define REG_CTRL_BITO_160PCC 0x03000
-#define REG_CTRL_GIBITO 0x08000
-#define REG_CTRL_CLTO__MASK 0x70000
-#define REG_CTRL_CLTO_OFF 0x00000
-
-#define REG_CMD 0x04
-#define REG_CMD_START 0x00001
-#define REG_CMD_STOP 0x00002
-#define REG_CMD_ACK 0x00004
-#define REG_CMD_NACK 0x00008
-#define REG_CMD_CONT 0x00010
-#define REG_CMD_ABORT 0x00020
-#define REG_CMD_CLEARTX 0x00040
-#define REG_CMD_CLEARPC 0x00080
-
-#define REG_STATE 0x08
-#define REG_STATE_BUSY 0x00001
-#define REG_STATE_MASTER 0x00002
-#define REG_STATE_TRANSMITTER 0x00004
-#define REG_STATE_NACKED 0x00008
-#define REG_STATE_BUSHOLD 0x00010
-#define REG_STATE_STATE__MASK 0x000e0
-#define REG_STATE_STATE_IDLE 0x00000
-#define REG_STATE_STATE_WAIT 0x00020
-#define REG_STATE_STATE_START 0x00040
-#define REG_STATE_STATE_ADDR 0x00060
-#define REG_STATE_STATE_ADDRACK 0x00080
-#define REG_STATE_STATE_DATA 0x000a0
-#define REG_STATE_STATE_DATAACK 0x000c0
-
-#define REG_STATUS 0x0c
-#define REG_STATUS_PSTART 0x00001
-#define REG_STATUS_PSTOP 0x00002
-#define REG_STATUS_PACK 0x00004
-#define REG_STATUS_PNACK 0x00008
-#define REG_STATUS_PCONT 0x00010
-#define REG_STATUS_PABORT 0x00020
-#define REG_STATUS_TXC 0x00040
-#define REG_STATUS_TXBL 0x00080
-#define REG_STATUS_RXDATAV 0x00100
-
-#define REG_CLKDIV 0x10
-#define REG_CLKDIV_DIV__MASK 0x001ff
-#define REG_CLKDIV_DIV(div) MASK_VAL(REG_CLKDIV_DIV__MASK, (div))
-
-#define REG_SADDR 0x14
-#define REG_SADDRMASK 0x18
-#define REG_RXDATA 0x1c
-#define REG_RXDATAP 0x20
-#define REG_TXDATA 0x24
-#define REG_IF 0x28
-#define REG_IF_START 0x00001
-#define REG_IF_RSTART 0x00002
-#define REG_IF_ADDR 0x00004
-#define REG_IF_TXC 0x00008
-#define REG_IF_TXBL 0x00010
-#define REG_IF_RXDATAV 0x00020
-#define REG_IF_ACK 0x00040
-#define REG_IF_NACK 0x00080
-#define REG_IF_MSTOP 0x00100
-#define REG_IF_ARBLOST 0x00200
-#define REG_IF_BUSERR 0x00400
-#define REG_IF_BUSHOLD 0x00800
-#define REG_IF_TXOF 0x01000
-#define REG_IF_RXUF 0x02000
-#define REG_IF_BITO 0x04000
-#define REG_IF_CLTO 0x08000
-#define REG_IF_SSTOP 0x10000
-
-#define REG_IFS 0x2c
-#define REG_IFC 0x30
-#define REG_IFC__MASK 0x1ffcf
-
-#define REG_IEN 0x34
-
-#define REG_ROUTE 0x38
-#define REG_ROUTE_SDAPEN 0x00001
-#define REG_ROUTE_SCLPEN 0x00002
-#define REG_ROUTE_LOCATION__MASK 0x00700
-#define REG_ROUTE_LOCATION(n) MASK_VAL(REG_ROUTE_LOCATION__MASK, (n))
-
-struct efm32_i2c_ddata {
- struct i2c_adapter adapter;
-
- struct clk *clk;
- void __iomem *base;
- unsigned int irq;
- u8 location;
- unsigned long frequency;
-
- /* transfer data */
- struct completion done;
- struct i2c_msg *msgs;
- size_t num_msgs;
- size_t current_word, current_msg;
- int retval;
-};
-
-static u32 efm32_i2c_read32(struct efm32_i2c_ddata *ddata, unsigned offset)
-{
- return readl(ddata->base + offset);
-}
-
-static void efm32_i2c_write32(struct efm32_i2c_ddata *ddata,
- unsigned offset, u32 value)
-{
- writel(value, ddata->base + offset);
-}
-
-static void efm32_i2c_send_next_msg(struct efm32_i2c_ddata *ddata)
-{
- struct i2c_msg *cur_msg = &ddata->msgs[ddata->current_msg];
-
- efm32_i2c_write32(ddata, REG_CMD, REG_CMD_START);
- efm32_i2c_write32(ddata, REG_TXDATA, i2c_8bit_addr_from_msg(cur_msg));
-}
-
-static void efm32_i2c_send_next_byte(struct efm32_i2c_ddata *ddata)
-{
- struct i2c_msg *cur_msg = &ddata->msgs[ddata->current_msg];
-
- if (ddata->current_word >= cur_msg->len) {
- /* cur_msg completely transferred */
- ddata->current_word = 0;
- ddata->current_msg += 1;
-
- if (ddata->current_msg >= ddata->num_msgs) {
- efm32_i2c_write32(ddata, REG_CMD, REG_CMD_STOP);
- complete(&ddata->done);
- } else {
- efm32_i2c_send_next_msg(ddata);
- }
- } else {
- efm32_i2c_write32(ddata, REG_TXDATA,
- cur_msg->buf[ddata->current_word++]);
- }
-}
-
-static void efm32_i2c_recv_next_byte(struct efm32_i2c_ddata *ddata)
-{
- struct i2c_msg *cur_msg = &ddata->msgs[ddata->current_msg];
-
- cur_msg->buf[ddata->current_word] = efm32_i2c_read32(ddata, REG_RXDATA);
- ddata->current_word += 1;
- if (ddata->current_word >= cur_msg->len) {
- /* cur_msg completely transferred */
- ddata->current_word = 0;
- ddata->current_msg += 1;
-
- efm32_i2c_write32(ddata, REG_CMD, REG_CMD_NACK);
-
- if (ddata->current_msg >= ddata->num_msgs) {
- efm32_i2c_write32(ddata, REG_CMD, REG_CMD_STOP);
- complete(&ddata->done);
- } else {
- efm32_i2c_send_next_msg(ddata);
- }
- } else {
- efm32_i2c_write32(ddata, REG_CMD, REG_CMD_ACK);
- }
-}
-
-static irqreturn_t efm32_i2c_irq(int irq, void *dev_id)
-{
- struct efm32_i2c_ddata *ddata = dev_id;
- struct i2c_msg *cur_msg = &ddata->msgs[ddata->current_msg];
- u32 irqflag = efm32_i2c_read32(ddata, REG_IF);
- u32 state = efm32_i2c_read32(ddata, REG_STATE);
-
- efm32_i2c_write32(ddata, REG_IFC, irqflag & REG_IFC__MASK);
-
- switch (state & REG_STATE_STATE__MASK) {
- case REG_STATE_STATE_IDLE:
- /* arbitration lost? */
- ddata->retval = -EAGAIN;
- complete(&ddata->done);
- break;
- case REG_STATE_STATE_WAIT:
- /*
- * huh, this shouldn't happen.
- * Reset hardware state and get out
- */
- ddata->retval = -EIO;
- efm32_i2c_write32(ddata, REG_CMD,
- REG_CMD_STOP | REG_CMD_ABORT |
- REG_CMD_CLEARTX | REG_CMD_CLEARPC);
- complete(&ddata->done);
- break;
- case REG_STATE_STATE_START:
- /* "caller" is expected to send an address */
- break;
- case REG_STATE_STATE_ADDR:
- /* wait for Ack or NAck of slave */
- break;
- case REG_STATE_STATE_ADDRACK:
- if (state & REG_STATE_NACKED) {
- efm32_i2c_write32(ddata, REG_CMD, REG_CMD_STOP);
- ddata->retval = -ENXIO;
- complete(&ddata->done);
- } else if (cur_msg->flags & I2C_M_RD) {
- /* wait for slave to send first data byte */
- } else {
- efm32_i2c_send_next_byte(ddata);
- }
- break;
- case REG_STATE_STATE_DATA:
- if (cur_msg->flags & I2C_M_RD) {
- efm32_i2c_recv_next_byte(ddata);
- } else {
- /* wait for Ack or Nack of slave */
- }
- break;
- case REG_STATE_STATE_DATAACK:
- if (state & REG_STATE_NACKED) {
- efm32_i2c_write32(ddata, REG_CMD, REG_CMD_STOP);
- complete(&ddata->done);
- } else {
- efm32_i2c_send_next_byte(ddata);
- }
- }
-
- return IRQ_HANDLED;
-}
-
-static int efm32_i2c_master_xfer(struct i2c_adapter *adap,
- struct i2c_msg *msgs, int num)
-{
- struct efm32_i2c_ddata *ddata = i2c_get_adapdata(adap);
- int ret;
-
- if (ddata->msgs)
- return -EBUSY;
-
- ddata->msgs = msgs;
- ddata->num_msgs = num;
- ddata->current_word = 0;
- ddata->current_msg = 0;
- ddata->retval = -EIO;
-
- reinit_completion(&ddata->done);
-
- dev_dbg(&ddata->adapter.dev, "state: %08x, status: %08x\n",
- efm32_i2c_read32(ddata, REG_STATE),
- efm32_i2c_read32(ddata, REG_STATUS));
-
- efm32_i2c_send_next_msg(ddata);
-
- wait_for_completion(&ddata->done);
-
- if (ddata->current_msg >= ddata->num_msgs)
- ret = ddata->num_msgs;
- else
- ret = ddata->retval;
-
- return ret;
-}
-
-static u32 efm32_i2c_functionality(struct i2c_adapter *adap)
-{
- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
-}
-
-static const struct i2c_algorithm efm32_i2c_algo = {
- .master_xfer = efm32_i2c_master_xfer,
- .functionality = efm32_i2c_functionality,
-};
-
-static u32 efm32_i2c_get_configured_location(struct efm32_i2c_ddata *ddata)
-{
- u32 reg = efm32_i2c_read32(ddata, REG_ROUTE);
-
- return (reg & REG_ROUTE_LOCATION__MASK) >>
- __ffs(REG_ROUTE_LOCATION__MASK);
-}
-
-static int efm32_i2c_probe(struct platform_device *pdev)
-{
- struct efm32_i2c_ddata *ddata;
- struct resource *res;
- unsigned long rate;
- struct device_node *np = pdev->dev.of_node;
- u32 location, frequency;
- int ret;
- u32 clkdiv;
-
- ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
- if (!ddata)
- return -ENOMEM;
- platform_set_drvdata(pdev, ddata);
-
- init_completion(&ddata->done);
- strlcpy(ddata->adapter.name, pdev->name, sizeof(ddata->adapter.name));
- ddata->adapter.owner = THIS_MODULE;
- ddata->adapter.algo = &efm32_i2c_algo;
- ddata->adapter.dev.parent = &pdev->dev;
- ddata->adapter.dev.of_node = pdev->dev.of_node;
- i2c_set_adapdata(&ddata->adapter, ddata);
-
- ddata->clk = devm_clk_get(&pdev->dev, NULL);
- if (IS_ERR(ddata->clk)) {
- ret = PTR_ERR(ddata->clk);
- dev_err(&pdev->dev, "failed to get clock: %d\n", ret);
- return ret;
- }
-
- ddata->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
- if (IS_ERR(ddata->base))
- return PTR_ERR(ddata->base);
-
- if (resource_size(res) < 0x42) {
- dev_err(&pdev->dev, "memory resource too small\n");
- return -EINVAL;
- }
-
- ret = platform_get_irq(pdev, 0);
- if (ret <= 0) {
- if (!ret)
- ret = -EINVAL;
- return ret;
- }
-
- ddata->irq = ret;
-
- ret = clk_prepare_enable(ddata->clk);
- if (ret < 0) {
- dev_err(&pdev->dev, "failed to enable clock (%d)\n", ret);
- return ret;
- }
-
-
- ret = of_property_read_u32(np, "energymicro,location", &location);
-
- if (ret)
- /* fall back to wrongly namespaced property */
- ret = of_property_read_u32(np, "efm32,location", &location);
-
- if (!ret) {
- dev_dbg(&pdev->dev, "using location %u\n", location);
- } else {
- /* default to location configured in hardware */
- location = efm32_i2c_get_configured_location(ddata);
-
- dev_info(&pdev->dev, "fall back to location %u\n", location);
- }
-
- ddata->location = location;
-
- ret = of_property_read_u32(np, "clock-frequency", &frequency);
- if (!ret) {
- dev_dbg(&pdev->dev, "using frequency %u\n", frequency);
- } else {
- frequency = I2C_MAX_STANDARD_MODE_FREQ;
- dev_info(&pdev->dev, "defaulting to 100 kHz\n");
- }
- ddata->frequency = frequency;
-
- rate = clk_get_rate(ddata->clk);
- if (!rate) {
- dev_err(&pdev->dev, "there is no input clock available\n");
- ret = -EINVAL;
- goto err_disable_clk;
- }
- clkdiv = DIV_ROUND_UP(rate, 8 * ddata->frequency) - 1;
- if (clkdiv >= 0x200) {
- dev_err(&pdev->dev,
- "input clock too fast (%lu) to divide down to bus freq (%lu)",
- rate, ddata->frequency);
- ret = -EINVAL;
- goto err_disable_clk;
- }
-
- dev_dbg(&pdev->dev, "input clock = %lu, bus freq = %lu, clkdiv = %lu\n",
- rate, ddata->frequency, (unsigned long)clkdiv);
- efm32_i2c_write32(ddata, REG_CLKDIV, REG_CLKDIV_DIV(clkdiv));
-
- efm32_i2c_write32(ddata, REG_ROUTE, REG_ROUTE_SDAPEN |
- REG_ROUTE_SCLPEN |
- REG_ROUTE_LOCATION(ddata->location));
-
- efm32_i2c_write32(ddata, REG_CTRL, REG_CTRL_EN |
- REG_CTRL_BITO_160PCC | 0 * REG_CTRL_GIBITO);
-
- efm32_i2c_write32(ddata, REG_IFC, REG_IFC__MASK);
- efm32_i2c_write32(ddata, REG_IEN, REG_IF_TXC | REG_IF_ACK | REG_IF_NACK
- | REG_IF_ARBLOST | REG_IF_BUSERR | REG_IF_RXDATAV);
-
- /* to make bus idle */
- efm32_i2c_write32(ddata, REG_CMD, REG_CMD_ABORT);
-
- ret = request_irq(ddata->irq, efm32_i2c_irq, 0, DRIVER_NAME, ddata);
- if (ret < 0) {
- dev_err(&pdev->dev, "failed to request irq (%d)\n", ret);
- goto err_disable_clk;
- }
-
- ret = i2c_add_adapter(&ddata->adapter);
- if (ret) {
- free_irq(ddata->irq, ddata);
-
-err_disable_clk:
- clk_disable_unprepare(ddata->clk);
- }
- return ret;
-}
-
-static int efm32_i2c_remove(struct platform_device *pdev)
-{
- struct efm32_i2c_ddata *ddata = platform_get_drvdata(pdev);
-
- i2c_del_adapter(&ddata->adapter);
- free_irq(ddata->irq, ddata);
- clk_disable_unprepare(ddata->clk);
-
- return 0;
-}
-
-static const struct of_device_id efm32_i2c_dt_ids[] = {
- {
- .compatible = "energymicro,efm32-i2c",
- }, {
- /* sentinel */
- }
-};
-MODULE_DEVICE_TABLE(of, efm32_i2c_dt_ids);
-
-static struct platform_driver efm32_i2c_driver = {
- .probe = efm32_i2c_probe,
- .remove = efm32_i2c_remove,
-
- .driver = {
- .name = DRIVER_NAME,
- .of_match_table = efm32_i2c_dt_ids,
- },
-};
-module_platform_driver(efm32_i2c_driver);
-
-MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");
-MODULE_DESCRIPTION("EFM32 i2c driver");
-MODULE_LICENSE("GPL v2");
-MODULE_ALIAS("platform:" DRIVER_NAME);
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