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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/media/rc/mtk-cir.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/media/rc/mtk-cir.c')
-rw-r--r-- | drivers/media/rc/mtk-cir.c | 453 |
1 files changed, 453 insertions, 0 deletions
diff --git a/drivers/media/rc/mtk-cir.c b/drivers/media/rc/mtk-cir.c new file mode 100644 index 0000000000..4e294e59d3 --- /dev/null +++ b/drivers/media/rc/mtk-cir.c @@ -0,0 +1,453 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Driver for Mediatek IR Receiver Controller + * + * Copyright (C) 2017 Sean Wang <sean.wang@mediatek.com> + */ + +#include <linux/clk.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/reset.h> +#include <media/rc-core.h> + +#define MTK_IR_DEV KBUILD_MODNAME + +/* Register to enable PWM and IR */ +#define MTK_CONFIG_HIGH_REG 0x0c + +/* Bit to enable IR pulse width detection */ +#define MTK_PWM_EN BIT(13) + +/* + * Register to setting ok count whose unit based on hardware sampling period + * indicating IR receiving completion and then making IRQ fires + */ +#define MTK_OK_COUNT_MASK (GENMASK(22, 16)) +#define MTK_OK_COUNT(x) ((x) << 16) + +/* Bit to enable IR hardware function */ +#define MTK_IR_EN BIT(0) + +/* Bit to restart IR receiving */ +#define MTK_IRCLR BIT(0) + +/* Fields containing pulse width data */ +#define MTK_WIDTH_MASK (GENMASK(7, 0)) + +/* IR threshold */ +#define MTK_IRTHD 0x14 +#define MTK_DG_CNT_MASK (GENMASK(12, 8)) +#define MTK_DG_CNT(x) ((x) << 8) + +/* Bit to enable interrupt */ +#define MTK_IRINT_EN BIT(0) + +/* Bit to clear interrupt status */ +#define MTK_IRINT_CLR BIT(0) + +/* Maximum count of samples */ +#define MTK_MAX_SAMPLES 0xff +/* Indicate the end of IR message */ +#define MTK_IR_END(v, p) ((v) == MTK_MAX_SAMPLES && (p) == 0) +/* Number of registers to record the pulse width */ +#define MTK_CHKDATA_SZ 17 +/* Sample period in us */ +#define MTK_IR_SAMPLE 46 + +enum mtk_fields { + /* Register to setting software sampling period */ + MTK_CHK_PERIOD, + /* Register to setting hardware sampling period */ + MTK_HW_PERIOD, +}; + +enum mtk_regs { + /* Register to clear state of state machine */ + MTK_IRCLR_REG, + /* Register containing pulse width data */ + MTK_CHKDATA_REG, + /* Register to enable IR interrupt */ + MTK_IRINT_EN_REG, + /* Register to ack IR interrupt */ + MTK_IRINT_CLR_REG +}; + +static const u32 mt7623_regs[] = { + [MTK_IRCLR_REG] = 0x20, + [MTK_CHKDATA_REG] = 0x88, + [MTK_IRINT_EN_REG] = 0xcc, + [MTK_IRINT_CLR_REG] = 0xd0, +}; + +static const u32 mt7622_regs[] = { + [MTK_IRCLR_REG] = 0x18, + [MTK_CHKDATA_REG] = 0x30, + [MTK_IRINT_EN_REG] = 0x1c, + [MTK_IRINT_CLR_REG] = 0x20, +}; + +struct mtk_field_type { + u32 reg; + u8 offset; + u32 mask; +}; + +/* + * struct mtk_ir_data - This is the structure holding all differences among + various hardwares + * @regs: The pointer to the array holding registers offset + * @fields: The pointer to the array holding fields location + * @div: The internal divisor for the based reference clock + * @ok_count: The count indicating the completion of IR data + * receiving when count is reached + * @hw_period: The value indicating the hardware sampling period + */ +struct mtk_ir_data { + const u32 *regs; + const struct mtk_field_type *fields; + u8 div; + u8 ok_count; + u32 hw_period; +}; + +static const struct mtk_field_type mt7623_fields[] = { + [MTK_CHK_PERIOD] = {0x10, 8, GENMASK(20, 8)}, + [MTK_HW_PERIOD] = {0x10, 0, GENMASK(7, 0)}, +}; + +static const struct mtk_field_type mt7622_fields[] = { + [MTK_CHK_PERIOD] = {0x24, 0, GENMASK(24, 0)}, + [MTK_HW_PERIOD] = {0x10, 0, GENMASK(24, 0)}, +}; + +/* + * struct mtk_ir - This is the main datasructure for holding the state + * of the driver + * @dev: The device pointer + * @rc: The rc instrance + * @base: The mapped register i/o base + * @irq: The IRQ that we are using + * @clk: The clock that IR internal is using + * @bus: The clock that software decoder is using + * @data: Holding specific data for vaious platform + */ +struct mtk_ir { + struct device *dev; + struct rc_dev *rc; + void __iomem *base; + int irq; + struct clk *clk; + struct clk *bus; + const struct mtk_ir_data *data; +}; + +static inline u32 mtk_chkdata_reg(struct mtk_ir *ir, u32 i) +{ + return ir->data->regs[MTK_CHKDATA_REG] + 4 * i; +} + +static inline u32 mtk_chk_period(struct mtk_ir *ir) +{ + u32 val; + + /* + * Period for software decoder used in the + * unit of raw software sampling + */ + val = DIV_ROUND_CLOSEST(clk_get_rate(ir->bus), + USEC_PER_SEC * ir->data->div / MTK_IR_SAMPLE); + + dev_dbg(ir->dev, "@pwm clk = \t%lu\n", + clk_get_rate(ir->bus) / ir->data->div); + dev_dbg(ir->dev, "@chkperiod = %08x\n", val); + + return val; +} + +static void mtk_w32_mask(struct mtk_ir *ir, u32 val, u32 mask, unsigned int reg) +{ + u32 tmp; + + tmp = __raw_readl(ir->base + reg); + tmp = (tmp & ~mask) | val; + __raw_writel(tmp, ir->base + reg); +} + +static void mtk_w32(struct mtk_ir *ir, u32 val, unsigned int reg) +{ + __raw_writel(val, ir->base + reg); +} + +static u32 mtk_r32(struct mtk_ir *ir, unsigned int reg) +{ + return __raw_readl(ir->base + reg); +} + +static inline void mtk_irq_disable(struct mtk_ir *ir, u32 mask) +{ + u32 val; + + val = mtk_r32(ir, ir->data->regs[MTK_IRINT_EN_REG]); + mtk_w32(ir, val & ~mask, ir->data->regs[MTK_IRINT_EN_REG]); +} + +static inline void mtk_irq_enable(struct mtk_ir *ir, u32 mask) +{ + u32 val; + + val = mtk_r32(ir, ir->data->regs[MTK_IRINT_EN_REG]); + mtk_w32(ir, val | mask, ir->data->regs[MTK_IRINT_EN_REG]); +} + +static irqreturn_t mtk_ir_irq(int irqno, void *dev_id) +{ + struct ir_raw_event rawir = {}; + struct mtk_ir *ir = dev_id; + u32 i, j, val; + u8 wid; + + /* + * Each pulse and space is encoded as a single byte, each byte + * alternating between pulse and space. If a pulse or space is longer + * than can be encoded in a single byte, it is encoded as the maximum + * value 0xff. + * + * If a space is longer than ok_count (about 23ms), the value is + * encoded as zero, and all following bytes are zero. Any IR that + * follows will be presented in the next interrupt. + * + * If there are more than 68 (=MTK_CHKDATA_SZ * 4) pulses and spaces, + * then the only the first 68 will be presented; the rest is lost. + */ + + /* Handle all pulse and space IR controller captures */ + for (i = 0 ; i < MTK_CHKDATA_SZ ; i++) { + val = mtk_r32(ir, mtk_chkdata_reg(ir, i)); + dev_dbg(ir->dev, "@reg%d=0x%08x\n", i, val); + + for (j = 0 ; j < 4 ; j++) { + wid = val & MTK_WIDTH_MASK; + val >>= 8; + rawir.pulse = !rawir.pulse; + rawir.duration = wid * (MTK_IR_SAMPLE + 1); + ir_raw_event_store_with_filter(ir->rc, &rawir); + } + } + + /* + * The maximum number of edges the IR controller can + * hold is MTK_CHKDATA_SZ * 4. So if received IR messages + * is over the limit, the last incomplete IR message would + * be appended trailing space and still would be sent into + * ir-rc-raw to decode. That helps it is possible that it + * has enough information to decode a scancode even if the + * trailing end of the message is missing. + */ + if (!MTK_IR_END(wid, rawir.pulse)) { + rawir.pulse = false; + rawir.duration = MTK_MAX_SAMPLES * (MTK_IR_SAMPLE + 1); + ir_raw_event_store_with_filter(ir->rc, &rawir); + } + + ir_raw_event_handle(ir->rc); + + /* + * Restart controller for the next receive that would + * clear up all CHKDATA registers + */ + mtk_w32_mask(ir, 0x1, MTK_IRCLR, ir->data->regs[MTK_IRCLR_REG]); + + /* Clear interrupt status */ + mtk_w32_mask(ir, 0x1, MTK_IRINT_CLR, + ir->data->regs[MTK_IRINT_CLR_REG]); + + return IRQ_HANDLED; +} + +static const struct mtk_ir_data mt7623_data = { + .regs = mt7623_regs, + .fields = mt7623_fields, + .ok_count = 3, + .hw_period = 0xff, + .div = 4, +}; + +static const struct mtk_ir_data mt7622_data = { + .regs = mt7622_regs, + .fields = mt7622_fields, + .ok_count = 3, + .hw_period = 0xffff, + .div = 32, +}; + +static const struct of_device_id mtk_ir_match[] = { + { .compatible = "mediatek,mt7623-cir", .data = &mt7623_data}, + { .compatible = "mediatek,mt7622-cir", .data = &mt7622_data}, + {}, +}; +MODULE_DEVICE_TABLE(of, mtk_ir_match); + +static int mtk_ir_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *dn = dev->of_node; + struct mtk_ir *ir; + u32 val; + int ret = 0; + const char *map_name; + + ir = devm_kzalloc(dev, sizeof(struct mtk_ir), GFP_KERNEL); + if (!ir) + return -ENOMEM; + + ir->dev = dev; + ir->data = of_device_get_match_data(dev); + + ir->clk = devm_clk_get(dev, "clk"); + if (IS_ERR(ir->clk)) { + dev_err(dev, "failed to get a ir clock.\n"); + return PTR_ERR(ir->clk); + } + + ir->bus = devm_clk_get(dev, "bus"); + if (IS_ERR(ir->bus)) { + /* + * For compatibility with older device trees try unnamed + * ir->bus uses the same clock as ir->clock. + */ + ir->bus = ir->clk; + } + + ir->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(ir->base)) + return PTR_ERR(ir->base); + + ir->rc = devm_rc_allocate_device(dev, RC_DRIVER_IR_RAW); + if (!ir->rc) { + dev_err(dev, "failed to allocate device\n"); + return -ENOMEM; + } + + ir->rc->priv = ir; + ir->rc->device_name = MTK_IR_DEV; + ir->rc->input_phys = MTK_IR_DEV "/input0"; + ir->rc->input_id.bustype = BUS_HOST; + ir->rc->input_id.vendor = 0x0001; + ir->rc->input_id.product = 0x0001; + ir->rc->input_id.version = 0x0001; + map_name = of_get_property(dn, "linux,rc-map-name", NULL); + ir->rc->map_name = map_name ?: RC_MAP_EMPTY; + ir->rc->dev.parent = dev; + ir->rc->driver_name = MTK_IR_DEV; + ir->rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER; + ir->rc->rx_resolution = MTK_IR_SAMPLE; + ir->rc->timeout = MTK_MAX_SAMPLES * (MTK_IR_SAMPLE + 1); + + ret = devm_rc_register_device(dev, ir->rc); + if (ret) { + dev_err(dev, "failed to register rc device\n"); + return ret; + } + + platform_set_drvdata(pdev, ir); + + ir->irq = platform_get_irq(pdev, 0); + if (ir->irq < 0) + return -ENODEV; + + if (clk_prepare_enable(ir->clk)) { + dev_err(dev, "try to enable ir_clk failed\n"); + return -EINVAL; + } + + if (clk_prepare_enable(ir->bus)) { + dev_err(dev, "try to enable ir_clk failed\n"); + ret = -EINVAL; + goto exit_clkdisable_clk; + } + + /* + * Enable interrupt after proper hardware + * setup and IRQ handler registration + */ + mtk_irq_disable(ir, MTK_IRINT_EN); + + ret = devm_request_irq(dev, ir->irq, mtk_ir_irq, 0, MTK_IR_DEV, ir); + if (ret) { + dev_err(dev, "failed request irq\n"); + goto exit_clkdisable_bus; + } + + /* + * Setup software sample period as the reference of software decoder + */ + val = (mtk_chk_period(ir) << ir->data->fields[MTK_CHK_PERIOD].offset) & + ir->data->fields[MTK_CHK_PERIOD].mask; + mtk_w32_mask(ir, val, ir->data->fields[MTK_CHK_PERIOD].mask, + ir->data->fields[MTK_CHK_PERIOD].reg); + + /* + * Setup hardware sampling period used to setup the proper timeout for + * indicating end of IR receiving completion + */ + val = (ir->data->hw_period << ir->data->fields[MTK_HW_PERIOD].offset) & + ir->data->fields[MTK_HW_PERIOD].mask; + mtk_w32_mask(ir, val, ir->data->fields[MTK_HW_PERIOD].mask, + ir->data->fields[MTK_HW_PERIOD].reg); + + /* Set de-glitch counter */ + mtk_w32_mask(ir, MTK_DG_CNT(1), MTK_DG_CNT_MASK, MTK_IRTHD); + + /* Enable IR and PWM */ + val = mtk_r32(ir, MTK_CONFIG_HIGH_REG) & ~MTK_OK_COUNT_MASK; + val |= MTK_OK_COUNT(ir->data->ok_count) | MTK_PWM_EN | MTK_IR_EN; + mtk_w32(ir, val, MTK_CONFIG_HIGH_REG); + + mtk_irq_enable(ir, MTK_IRINT_EN); + + dev_info(dev, "Initialized MT7623 IR driver, sample period = %dus\n", + MTK_IR_SAMPLE); + + return 0; + +exit_clkdisable_bus: + clk_disable_unprepare(ir->bus); +exit_clkdisable_clk: + clk_disable_unprepare(ir->clk); + + return ret; +} + +static void mtk_ir_remove(struct platform_device *pdev) +{ + struct mtk_ir *ir = platform_get_drvdata(pdev); + + /* + * Avoid contention between remove handler and + * IRQ handler so that disabling IR interrupt and + * waiting for pending IRQ handler to complete + */ + mtk_irq_disable(ir, MTK_IRINT_EN); + synchronize_irq(ir->irq); + + clk_disable_unprepare(ir->bus); + clk_disable_unprepare(ir->clk); +} + +static struct platform_driver mtk_ir_driver = { + .probe = mtk_ir_probe, + .remove_new = mtk_ir_remove, + .driver = { + .name = MTK_IR_DEV, + .of_match_table = mtk_ir_match, + }, +}; + +module_platform_driver(mtk_ir_driver); + +MODULE_DESCRIPTION("Mediatek IR Receiver Controller Driver"); +MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>"); +MODULE_LICENSE("GPL"); |