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Alexander Shiyan161b96c2012-11-07 21:30:29 +04001/*
2 * CLPS711X SPI bus driver
3 *
Alexander Shiyan98984792014-01-10 17:02:05 +04004 * Copyright (C) 2012-2014 Alexander Shiyan <shc_work@mail.ru>
Alexander Shiyan161b96c2012-11-07 21:30:29 +04005 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 */
11
12#include <linux/io.h>
13#include <linux/clk.h>
Alexander Shiyan161b96c2012-11-07 21:30:29 +040014#include <linux/gpio.h>
15#include <linux/delay.h>
16#include <linux/module.h>
17#include <linux/interrupt.h>
18#include <linux/platform_device.h>
Alexander Shiyan3dc92592014-03-22 10:57:35 +040019#include <linux/regmap.h>
20#include <linux/mfd/syscon.h>
21#include <linux/mfd/syscon/clps711x.h>
Alexander Shiyan161b96c2012-11-07 21:30:29 +040022#include <linux/spi/spi.h>
23#include <linux/platform_data/spi-clps711x.h>
24
Alexander Shiyan161b96c2012-11-07 21:30:29 +040025#define DRIVER_NAME "spi-clps711x"
26
Alexander Shiyan3dc92592014-03-22 10:57:35 +040027#define SYNCIO_FRMLEN(x) ((x) << 8)
28#define SYNCIO_TXFRMEN (1 << 14)
29
Alexander Shiyan161b96c2012-11-07 21:30:29 +040030struct spi_clps711x_data {
Alexander Shiyan3dc92592014-03-22 10:57:35 +040031 void __iomem *syncio;
32 struct regmap *syscon;
Alexander Shiyan161b96c2012-11-07 21:30:29 +040033 struct clk *spi_clk;
Alexander Shiyan161b96c2012-11-07 21:30:29 +040034
35 u8 *tx_buf;
36 u8 *rx_buf;
Alexander Shiyan8dda9d92014-02-02 10:59:49 +040037 unsigned int bpw;
Alexander Shiyan161b96c2012-11-07 21:30:29 +040038 int len;
Alexander Shiyan161b96c2012-11-07 21:30:29 +040039};
40
41static int spi_clps711x_setup(struct spi_device *spi)
42{
Alexander Shiyan161b96c2012-11-07 21:30:29 +040043 /* We are expect that SPI-device is not selected */
Alexander Shiyan3e9ea4b2014-02-02 10:59:50 +040044 gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
Alexander Shiyan161b96c2012-11-07 21:30:29 +040045
46 return 0;
47}
48
Axel Linbf5c2e22014-02-18 17:15:54 +080049static int spi_clps711x_prepare_message(struct spi_master *master,
50 struct spi_message *msg)
Alexander Shiyan161b96c2012-11-07 21:30:29 +040051{
Alexander Shiyan3dc92592014-03-22 10:57:35 +040052 struct spi_clps711x_data *hw = spi_master_get_devdata(master);
Alexander Shiyan8dda9d92014-02-02 10:59:49 +040053 struct spi_device *spi = msg->spi;
Alexander Shiyan161b96c2012-11-07 21:30:29 +040054
Alexander Shiyan3dc92592014-03-22 10:57:35 +040055 /* Setup mode for transfer */
56 return regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCKNSEN,
57 (spi->mode & SPI_CPHA) ?
58 SYSCON3_ADCCKNSEN : 0);
Alexander Shiyan161b96c2012-11-07 21:30:29 +040059}
60
Axel Linbf5c2e22014-02-18 17:15:54 +080061static int spi_clps711x_transfer_one(struct spi_master *master,
62 struct spi_device *spi,
63 struct spi_transfer *xfer)
64{
65 struct spi_clps711x_data *hw = spi_master_get_devdata(master);
66 u8 data;
67
Alexander Shiyana5b4b232014-09-20 11:05:09 +040068 clk_set_rate(hw->spi_clk, xfer->speed_hz ? : spi->max_speed_hz);
Axel Linbf5c2e22014-02-18 17:15:54 +080069
70 hw->len = xfer->len;
Axel Linbed890b2014-03-02 23:24:18 +080071 hw->bpw = xfer->bits_per_word;
Axel Linbf5c2e22014-02-18 17:15:54 +080072 hw->tx_buf = (u8 *)xfer->tx_buf;
73 hw->rx_buf = (u8 *)xfer->rx_buf;
74
75 /* Initiate transfer */
76 data = hw->tx_buf ? *hw->tx_buf++ : 0;
Alexander Shiyan3dc92592014-03-22 10:57:35 +040077 writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN, hw->syncio);
78
Axel Linbf5c2e22014-02-18 17:15:54 +080079 return 1;
80}
81
Alexander Shiyan161b96c2012-11-07 21:30:29 +040082static irqreturn_t spi_clps711x_isr(int irq, void *dev_id)
83{
Axel Linbf5c2e22014-02-18 17:15:54 +080084 struct spi_master *master = dev_id;
85 struct spi_clps711x_data *hw = spi_master_get_devdata(master);
Alexander Shiyanc7a26f12014-02-02 10:59:48 +040086 u8 data;
Alexander Shiyan161b96c2012-11-07 21:30:29 +040087
88 /* Handle RX */
Alexander Shiyan3dc92592014-03-22 10:57:35 +040089 data = readb(hw->syncio);
Alexander Shiyan161b96c2012-11-07 21:30:29 +040090 if (hw->rx_buf)
Alexander Shiyanc7a26f12014-02-02 10:59:48 +040091 *hw->rx_buf++ = data;
Alexander Shiyan161b96c2012-11-07 21:30:29 +040092
93 /* Handle TX */
Alexander Shiyanc7a26f12014-02-02 10:59:48 +040094 if (--hw->len > 0) {
95 data = hw->tx_buf ? *hw->tx_buf++ : 0;
Alexander Shiyan3dc92592014-03-22 10:57:35 +040096 writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN,
97 hw->syncio);
Alexander Shiyan161b96c2012-11-07 21:30:29 +040098 } else
Axel Linbf5c2e22014-02-18 17:15:54 +080099 spi_finalize_current_transfer(master);
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400100
101 return IRQ_HANDLED;
102}
103
Grant Likelyfd4a3192012-12-07 16:57:14 +0000104static int spi_clps711x_probe(struct platform_device *pdev)
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400105{
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400106 struct spi_clps711x_data *hw;
107 struct spi_clps711x_pdata *pdata = dev_get_platdata(&pdev->dev);
Alexander Shiyan3dc92592014-03-22 10:57:35 +0400108 struct spi_master *master;
109 struct resource *res;
110 int i, irq, ret;
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400111
112 if (!pdata) {
113 dev_err(&pdev->dev, "No platform data supplied\n");
114 return -EINVAL;
115 }
116
117 if (pdata->num_chipselect < 1) {
118 dev_err(&pdev->dev, "At least one CS must be defined\n");
119 return -EINVAL;
120 }
121
Alexander Shiyan3dc92592014-03-22 10:57:35 +0400122 irq = platform_get_irq(pdev, 0);
123 if (irq < 0)
124 return irq;
125
Alexander Shiyan3e9ea4b2014-02-02 10:59:50 +0400126 master = spi_alloc_master(&pdev->dev, sizeof(*hw));
127 if (!master)
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400128 return -ENOMEM;
Alexander Shiyan3e9ea4b2014-02-02 10:59:50 +0400129
130 master->cs_gpios = devm_kzalloc(&pdev->dev, sizeof(int) *
131 pdata->num_chipselect, GFP_KERNEL);
132 if (!master->cs_gpios) {
133 ret = -ENOMEM;
134 goto err_out;
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400135 }
136
137 master->bus_num = pdev->id;
138 master->mode_bits = SPI_CPHA | SPI_CS_HIGH;
Alexander Shiyan8dda9d92014-02-02 10:59:49 +0400139 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 8);
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400140 master->num_chipselect = pdata->num_chipselect;
141 master->setup = spi_clps711x_setup;
Axel Linbf5c2e22014-02-18 17:15:54 +0800142 master->prepare_message = spi_clps711x_prepare_message;
143 master->transfer_one = spi_clps711x_transfer_one;
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400144
145 hw = spi_master_get_devdata(master);
146
147 for (i = 0; i < master->num_chipselect; i++) {
Alexander Shiyan3e9ea4b2014-02-02 10:59:50 +0400148 master->cs_gpios[i] = pdata->chipselect[i];
Axel Linfcba2122014-03-04 12:59:53 +0800149 ret = devm_gpio_request(&pdev->dev, master->cs_gpios[i],
150 DRIVER_NAME);
151 if (ret) {
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400152 dev_err(&pdev->dev, "Can't get CS GPIO %i\n", i);
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400153 goto err_out;
154 }
155 }
156
Alexander Shiyana5b4b232014-09-20 11:05:09 +0400157 hw->spi_clk = devm_clk_get(&pdev->dev, NULL);
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400158 if (IS_ERR(hw->spi_clk)) {
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400159 ret = PTR_ERR(hw->spi_clk);
160 goto err_out;
161 }
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400162
Alexander Shiyan3dc92592014-03-22 10:57:35 +0400163 hw->syscon = syscon_regmap_lookup_by_pdevname("syscon.3");
164 if (IS_ERR(hw->syscon)) {
165 ret = PTR_ERR(hw->syscon);
Sachin Kamatc7083792013-09-27 15:32:53 +0530166 goto err_out;
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400167 }
168
Alexander Shiyan3dc92592014-03-22 10:57:35 +0400169 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
170 hw->syncio = devm_ioremap_resource(&pdev->dev, res);
171 if (IS_ERR(hw->syncio)) {
172 ret = PTR_ERR(hw->syncio);
173 goto err_out;
174 }
175
176 /* Disable extended mode due hardware problems */
177 regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCON, 0);
178
179 /* Clear possible pending interrupt */
180 readl(hw->syncio);
181
182 ret = devm_request_irq(&pdev->dev, irq, spi_clps711x_isr, 0,
183 dev_name(&pdev->dev), master);
184 if (ret)
185 goto err_out;
186
Jingoo Hanc493fc42013-09-24 13:27:48 +0900187 ret = devm_spi_register_master(&pdev->dev, master);
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400188 if (!ret) {
189 dev_info(&pdev->dev,
190 "SPI bus driver initialized. Master clock %u Hz\n",
Axel Lin6f50c6bc2014-03-26 23:44:18 +0800191 master->max_speed_hz);
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400192 return 0;
193 }
194
195 dev_err(&pdev->dev, "Failed to register master\n");
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400196
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400197err_out:
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400198 spi_master_put(master);
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400199
200 return ret;
201}
202
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400203static struct platform_driver clps711x_spi_driver = {
204 .driver = {
205 .name = DRIVER_NAME,
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400206 },
207 .probe = spi_clps711x_probe,
Alexander Shiyan161b96c2012-11-07 21:30:29 +0400208};
209module_platform_driver(clps711x_spi_driver);
210
211MODULE_LICENSE("GPL");
212MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
213MODULE_DESCRIPTION("CLPS711X SPI bus driver");
Axel Lin350a9b32014-01-14 17:01:54 +0800214MODULE_ALIAS("platform:" DRIVER_NAME);