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path: root/drivers/video/fbdev/mb862xx/mb862xx-i2c.c
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Diffstat (limited to 'drivers/video/fbdev/mb862xx/mb862xx-i2c.c')
-rw-r--r--drivers/video/fbdev/mb862xx/mb862xx-i2c.c168
1 files changed, 168 insertions, 0 deletions
diff --git a/drivers/video/fbdev/mb862xx/mb862xx-i2c.c b/drivers/video/fbdev/mb862xx/mb862xx-i2c.c
new file mode 100644
index 000000000..ffdb1597d
--- /dev/null
+++ b/drivers/video/fbdev/mb862xx/mb862xx-i2c.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Coral-P(A)/Lime I2C adapter driver
+ *
+ * (C) 2011 DENX Software Engineering, Anatolij Gustschin <agust@denx.de>
+ */
+
+#include <linux/fb.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+
+#include "mb862xxfb.h"
+#include "mb862xx_reg.h"
+
+static int mb862xx_i2c_wait_event(struct i2c_adapter *adap)
+{
+ struct mb862xxfb_par *par = adap->algo_data;
+ u32 reg;
+
+ do {
+ udelay(10);
+ reg = inreg(i2c, GC_I2C_BCR);
+ if (reg & (I2C_INT | I2C_BER))
+ break;
+ } while (1);
+
+ return (reg & I2C_BER) ? 0 : 1;
+}
+
+static int mb862xx_i2c_do_address(struct i2c_adapter *adap, int addr)
+{
+ struct mb862xxfb_par *par = adap->algo_data;
+
+ outreg(i2c, GC_I2C_DAR, addr);
+ outreg(i2c, GC_I2C_CCR, I2C_CLOCK_AND_ENABLE);
+ outreg(i2c, GC_I2C_BCR, par->i2c_rs ? I2C_REPEATED_START : I2C_START);
+ if (!mb862xx_i2c_wait_event(adap))
+ return -EIO;
+ par->i2c_rs = !(inreg(i2c, GC_I2C_BSR) & I2C_LRB);
+ return par->i2c_rs;
+}
+
+static int mb862xx_i2c_write_byte(struct i2c_adapter *adap, u8 byte)
+{
+ struct mb862xxfb_par *par = adap->algo_data;
+
+ outreg(i2c, GC_I2C_DAR, byte);
+ outreg(i2c, GC_I2C_BCR, I2C_START);
+ if (!mb862xx_i2c_wait_event(adap))
+ return -EIO;
+ return !(inreg(i2c, GC_I2C_BSR) & I2C_LRB);
+}
+
+static int mb862xx_i2c_read_byte(struct i2c_adapter *adap, u8 *byte, int last)
+{
+ struct mb862xxfb_par *par = adap->algo_data;
+
+ outreg(i2c, GC_I2C_BCR, I2C_START | (last ? 0 : I2C_ACK));
+ if (!mb862xx_i2c_wait_event(adap))
+ return 0;
+ *byte = inreg(i2c, GC_I2C_DAR);
+ return 1;
+}
+
+static void mb862xx_i2c_stop(struct i2c_adapter *adap)
+{
+ struct mb862xxfb_par *par = adap->algo_data;
+
+ outreg(i2c, GC_I2C_BCR, I2C_STOP);
+ outreg(i2c, GC_I2C_CCR, I2C_DISABLE);
+ par->i2c_rs = 0;
+}
+
+static int mb862xx_i2c_read(struct i2c_adapter *adap, struct i2c_msg *m)
+{
+ int i, ret = 0;
+ int last = m->len - 1;
+
+ for (i = 0; i < m->len; i++) {
+ if (!mb862xx_i2c_read_byte(adap, &m->buf[i], i == last)) {
+ ret = -EIO;
+ break;
+ }
+ }
+ return ret;
+}
+
+static int mb862xx_i2c_write(struct i2c_adapter *adap, struct i2c_msg *m)
+{
+ int i, ret = 0;
+
+ for (i = 0; i < m->len; i++) {
+ if (!mb862xx_i2c_write_byte(adap, m->buf[i])) {
+ ret = -EIO;
+ break;
+ }
+ }
+ return ret;
+}
+
+static int mb862xx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+ int num)
+{
+ struct mb862xxfb_par *par = adap->algo_data;
+ struct i2c_msg *m;
+ int addr;
+ int i = 0, err = 0;
+
+ dev_dbg(par->dev, "%s: %d msgs\n", __func__, num);
+
+ for (i = 0; i < num; i++) {
+ m = &msgs[i];
+ if (!m->len) {
+ dev_dbg(par->dev, "%s: null msgs\n", __func__);
+ continue;
+ }
+ addr = m->addr;
+ if (m->flags & I2C_M_RD)
+ addr |= 1;
+
+ err = mb862xx_i2c_do_address(adap, addr);
+ if (err < 0)
+ break;
+ if (m->flags & I2C_M_RD)
+ err = mb862xx_i2c_read(adap, m);
+ else
+ err = mb862xx_i2c_write(adap, m);
+ }
+
+ if (i)
+ mb862xx_i2c_stop(adap);
+
+ return (err < 0) ? err : i;
+}
+
+static u32 mb862xx_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_SMBUS_BYTE_DATA;
+}
+
+static const struct i2c_algorithm mb862xx_algo = {
+ .master_xfer = mb862xx_xfer,
+ .functionality = mb862xx_func,
+};
+
+static struct i2c_adapter mb862xx_i2c_adapter = {
+ .name = "MB862xx I2C adapter",
+ .algo = &mb862xx_algo,
+ .owner = THIS_MODULE,
+};
+
+int mb862xx_i2c_init(struct mb862xxfb_par *par)
+{
+ mb862xx_i2c_adapter.algo_data = par;
+ par->adap = &mb862xx_i2c_adapter;
+
+ return i2c_add_adapter(par->adap);
+}
+
+void mb862xx_i2c_exit(struct mb862xxfb_par *par)
+{
+ if (par->adap) {
+ i2c_del_adapter(par->adap);
+ par->adap = NULL;
+ }
+}