linux/drivers/media/platform/s5p-cec/exynos_hdmi_cecctrl.c
Hans Verkuil e949f61461 media: s5p-cec: add NACK detection support
The s5p-cec driver returned CEC_TX_STATUS_ERROR for the NACK condition.

Some digging into the datasheet uncovered the S5P_CEC_TX_STAT1 register where
bit 0 indicates if the transmit was nacked or not.

Use this to return the correct CEC_TX_STATUS_NACK status to userspace.

This was the only driver that couldn't tell a NACK from another error, and
that was very unusual. And a potential problem for applications as well.

Tested with my Odroid-U3.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: <stable@vger.kernel.org>      # for v4.12 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-23 07:29:30 -04:00

210 lines
4.8 KiB
C

/* drivers/media/platform/s5p-cec/exynos_hdmi_cecctrl.c
*
* Copyright (c) 2009, 2014 Samsung Electronics
* http://www.samsung.com/
*
* cec ftn file for Samsung TVOUT driver
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/io.h>
#include <linux/device.h>
#include "exynos_hdmi_cec.h"
#include "regs-cec.h"
#define S5P_HDMI_FIN 24000000
#define CEC_DIV_RATIO 320000
#define CEC_MESSAGE_BROADCAST_MASK 0x0F
#define CEC_MESSAGE_BROADCAST 0x0F
#define CEC_FILTER_THRESHOLD 0x15
void s5p_cec_set_divider(struct s5p_cec_dev *cec)
{
u32 div_ratio, div_val;
unsigned int reg;
div_ratio = S5P_HDMI_FIN / CEC_DIV_RATIO - 1;
if (regmap_read(cec->pmu, EXYNOS_HDMI_PHY_CONTROL, &reg)) {
dev_err(cec->dev, "failed to read phy control\n");
return;
}
reg = (reg & ~(0x3FF << 16)) | (div_ratio << 16);
if (regmap_write(cec->pmu, EXYNOS_HDMI_PHY_CONTROL, reg)) {
dev_err(cec->dev, "failed to write phy control\n");
return;
}
div_val = CEC_DIV_RATIO * 0.00005 - 1;
writeb(0x0, cec->reg + S5P_CEC_DIVISOR_3);
writeb(0x0, cec->reg + S5P_CEC_DIVISOR_2);
writeb(0x0, cec->reg + S5P_CEC_DIVISOR_1);
writeb(div_val, cec->reg + S5P_CEC_DIVISOR_0);
}
void s5p_cec_enable_rx(struct s5p_cec_dev *cec)
{
u8 reg;
reg = readb(cec->reg + S5P_CEC_RX_CTRL);
reg |= S5P_CEC_RX_CTRL_ENABLE;
writeb(reg, cec->reg + S5P_CEC_RX_CTRL);
}
void s5p_cec_mask_rx_interrupts(struct s5p_cec_dev *cec)
{
u8 reg;
reg = readb(cec->reg + S5P_CEC_IRQ_MASK);
reg |= S5P_CEC_IRQ_RX_DONE;
reg |= S5P_CEC_IRQ_RX_ERROR;
writeb(reg, cec->reg + S5P_CEC_IRQ_MASK);
}
void s5p_cec_unmask_rx_interrupts(struct s5p_cec_dev *cec)
{
u8 reg;
reg = readb(cec->reg + S5P_CEC_IRQ_MASK);
reg &= ~S5P_CEC_IRQ_RX_DONE;
reg &= ~S5P_CEC_IRQ_RX_ERROR;
writeb(reg, cec->reg + S5P_CEC_IRQ_MASK);
}
void s5p_cec_mask_tx_interrupts(struct s5p_cec_dev *cec)
{
u8 reg;
reg = readb(cec->reg + S5P_CEC_IRQ_MASK);
reg |= S5P_CEC_IRQ_TX_DONE;
reg |= S5P_CEC_IRQ_TX_ERROR;
writeb(reg, cec->reg + S5P_CEC_IRQ_MASK);
}
void s5p_cec_unmask_tx_interrupts(struct s5p_cec_dev *cec)
{
u8 reg;
reg = readb(cec->reg + S5P_CEC_IRQ_MASK);
reg &= ~S5P_CEC_IRQ_TX_DONE;
reg &= ~S5P_CEC_IRQ_TX_ERROR;
writeb(reg, cec->reg + S5P_CEC_IRQ_MASK);
}
void s5p_cec_reset(struct s5p_cec_dev *cec)
{
u8 reg;
writeb(S5P_CEC_RX_CTRL_RESET, cec->reg + S5P_CEC_RX_CTRL);
writeb(S5P_CEC_TX_CTRL_RESET, cec->reg + S5P_CEC_TX_CTRL);
reg = readb(cec->reg + 0xc4);
reg &= ~0x1;
writeb(reg, cec->reg + 0xc4);
}
void s5p_cec_tx_reset(struct s5p_cec_dev *cec)
{
writeb(S5P_CEC_TX_CTRL_RESET, cec->reg + S5P_CEC_TX_CTRL);
}
void s5p_cec_rx_reset(struct s5p_cec_dev *cec)
{
u8 reg;
writeb(S5P_CEC_RX_CTRL_RESET, cec->reg + S5P_CEC_RX_CTRL);
reg = readb(cec->reg + 0xc4);
reg &= ~0x1;
writeb(reg, cec->reg + 0xc4);
}
void s5p_cec_threshold(struct s5p_cec_dev *cec)
{
writeb(CEC_FILTER_THRESHOLD, cec->reg + S5P_CEC_RX_FILTER_TH);
writeb(0, cec->reg + S5P_CEC_RX_FILTER_CTRL);
}
void s5p_cec_copy_packet(struct s5p_cec_dev *cec, char *data,
size_t count, u8 retries)
{
int i = 0;
u8 reg;
while (i < count) {
writeb(data[i], cec->reg + (S5P_CEC_TX_BUFF0 + (i * 4)));
i++;
}
writeb(count, cec->reg + S5P_CEC_TX_BYTES);
reg = readb(cec->reg + S5P_CEC_TX_CTRL);
reg |= S5P_CEC_TX_CTRL_START;
reg &= ~0x70;
reg |= retries << 4;
if ((data[0] & CEC_MESSAGE_BROADCAST_MASK) == CEC_MESSAGE_BROADCAST) {
dev_dbg(cec->dev, "Broadcast");
reg |= S5P_CEC_TX_CTRL_BCAST;
} else {
dev_dbg(cec->dev, "No Broadcast");
reg &= ~S5P_CEC_TX_CTRL_BCAST;
}
writeb(reg, cec->reg + S5P_CEC_TX_CTRL);
dev_dbg(cec->dev, "cec-tx: cec count (%zu): %*ph", count,
(int)count, data);
}
void s5p_cec_set_addr(struct s5p_cec_dev *cec, u32 addr)
{
writeb(addr & 0x0F, cec->reg + S5P_CEC_LOGIC_ADDR);
}
u32 s5p_cec_get_status(struct s5p_cec_dev *cec)
{
u32 status = 0;
status = readb(cec->reg + S5P_CEC_STATUS_0) & 0xf;
status |= (readb(cec->reg + S5P_CEC_TX_STAT1) & 0xf) << 4;
status |= readb(cec->reg + S5P_CEC_STATUS_1) << 8;
status |= readb(cec->reg + S5P_CEC_STATUS_2) << 16;
status |= readb(cec->reg + S5P_CEC_STATUS_3) << 24;
dev_dbg(cec->dev, "status = 0x%x!\n", status);
return status;
}
void s5p_clr_pending_tx(struct s5p_cec_dev *cec)
{
writeb(S5P_CEC_IRQ_TX_DONE | S5P_CEC_IRQ_TX_ERROR,
cec->reg + S5P_CEC_IRQ_CLEAR);
}
void s5p_clr_pending_rx(struct s5p_cec_dev *cec)
{
writeb(S5P_CEC_IRQ_RX_DONE | S5P_CEC_IRQ_RX_ERROR,
cec->reg + S5P_CEC_IRQ_CLEAR);
}
void s5p_cec_get_rx_buf(struct s5p_cec_dev *cec, u32 size, u8 *buffer)
{
u32 i = 0;
char debug[40];
while (i < size) {
buffer[i] = readb(cec->reg + S5P_CEC_RX_BUFF0 + (i * 4));
sprintf(debug + i * 2, "%02x ", buffer[i]);
i++;
}
dev_dbg(cec->dev, "cec-rx: cec size(%d): %s", size, debug);
}