* [PATCH v17 0/3] Add ASPEED AST2600 I2C controller driver
@ 2025-08-14 8:41 Ryan Chen
2025-08-14 8:41 ` [PATCH v17 1/3] dt-bindings: i2c: aspeed,i2c.yaml: add transfer-mode and global-regs properties and update example Ryan Chen
` (2 more replies)
0 siblings, 3 replies; 8+ messages in thread
From: Ryan Chen @ 2025-08-14 8:41 UTC (permalink / raw)
To: ryan_chen, benh, joel, andi.shyti, robh, krzk+dt, conor+dt,
andrew, p.zabel, andriy.shevchenko, naresh.solanki, linux-i2c,
openbmc, devicetree, linux-arm-kernel, linux-aspeed, linux-kernel
This series add AST2600 i2c new register set driver. The i2c driver is
new register set that have new clock divider option for more flexiable
generation. And also have separate i2c controller and target register
set for control, patch #2 is i2c controller driver only, patch #3 is add
i2c target mode driver.
The legacy register layout is mix controller/target register control
together. The following is add more detail description about new register
layout. And new feature set add for register.
v17:
- move i2c new mode register and feature into driver commit message.
- aspeed,i2c.yaml
- remove multi-master properties.
- use aspeed,transfer-mode properties for aspeed,enable-byte/enable-dma.
-i2c-ast2600.c
- rename dma_safe_buf to controller_dma_safe_buf.
- fix ast2600_i2c_recover_bus return overflow warnings.
- add ast2600_i2c_target_packet_buff_irq unhandle case.
- add parameter "cmd" in ast2600_i2c_setup_dma_rx,
ast2600_i2c_setup_buff_rx, ast2600_i2c_setup_byte_rx
- use reset_control_deassert replace
devm_reset_control_get_shared_deasserted.
- useaspeed,transfer-mode properties for transfer mode setting.
- change compatible = "aspeed,ast2600-i2cv2" to "aspeed,ast2600-i2c-bus".
v16:
- aspeed,i2c.yaml: add aspeed,enable-byte properties for force byte mode.
- i2c-ast2600.c
- change include asm/unaligned.h to linux/unaligned.h.
- add reset timeout councter when slave active timeout.
- modify issue i2c_recovery_bus before slave re-enable.
- add aspeed,enable-byte properties.
v15:
- i2c-ast2600.c
- add include unaligned.h
- rename all master -> controller, slave -> target.
- keep multi-master to align property.
- remove no used element in ast2600_i2c_bus.
v14:
- aspeed,i2c.yaml
- v13 change people reviewed-by tag, v14 fixed to original people tag,
modify to Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
- struct ast2600_i2c_bus layout optimal.
- ast2600_select_i2c_clock refine.
- ast2600_i2c_recover_bus overridden fix.
- dma_mapping_error() returned error code shadowed modify.
- buffer register in a 4-byte aligned simplified
- remove smbus alert
v13:
- separate i2c master and slave driver to be two patchs.
- modify include header list, add bits.h include. remove of*.h
- modify (((x) >> 24) & GENMASK(5, 0)) to (((x) & GENMASK(29, 24)) >> 24)
- modify ast2600_select_i2c_clock function implement.
- modify ast2600_i2c_recover_bus function u32 claim to
u32 state = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
v12:
- aspeed,i2c.yaml
- add Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
- i2c-ast2600.c
- update include by alphabetical order
- make just a one TAB and put the last two lines on the single one
- remove no used timing_table structre
- remove enum explicit assinment
- rewritten to avoid this and using loop in ast2600_select_i2c_clock
- use GENMASK for most 0xffff
- remove too many parentheses
- use str_read_write replace read write string
- remove redundant blank line after ast2600_i2c_bus_of_table
- fix wrong multi-line style of the comment
- use macro for i2c standard speeds
- remove useless noise dev_info
v11:
- aspeed,i2c.yaml
- no change, the same with v10.
- i2c-ast2600.c
- modify alert_enable from int -> boolean.
- modify dbg string recovery -> recover.
- remove no need to init 0.
- remove new line after break.
- remove unneeded empty line.
- modify dma_alloc_coherent to dmam_alloc_coherent
- modify probe nomem return dev_err_probe
- modify i2c_add_adapter to devm_i2c_adapter
- modify checkpatch: Alignment should match open parenthesis
- modify checkpatch: braces {} should be used on all arms of this statement
- modify checkpatch: Unbalanced braces around else statement
v10:
- aspeed,i2c.yaml
- move unevaluatedProperties after allOf.
- remove extra one blank line.
- i2c-ast2600.c
- no change, the same with v8.
v9:
- aspeed,i2c.yaml
- backoff to v7.
- no fix typo in maintainer's name and email. this would be another patch.
- no remove address-cells, size-cells, this would be another patch.
- use aspeed,enable-dma property instead of aspeed,xfer-mode selection.
- fix allOf and else false properties for aspeed,ast2600-i2cv2.
- i2c-ast2600.c
- no change, the same with v8
v8:
- aspeed,i2c.yaml
- modify commit message.
- Fix typo in maintainer's name and email.
- remove address-cells, size-cells.
- i2c-ast2600.c
- move "i2c timeout counter" comment description before property_read.
- remove redundant code "return ret" in probe end.
v7:
- aspeed,i2c.yaml
- Update ASPEED I2C maintainers email.
- use aspeed,enable-dma property instead of aspeed,xfer-mode selection.
- fix allOf and else false properties for aspeed,ast2600-i2cv2.
- i2c-ast2600.c
- remove aspeed,xfer-mode instead of aspeed,enable-dma mode. buffer mode
is default.
- remove aspeed,timeout instead of i2c-scl-clk-low-timeout-us for
timeout setting.
v6:
- remove aspeed,i2cv2.yaml, merge to aspeed,i2c.yaml -add support for
i2cv2 properites.
- i2c-ast2600.c
- fix ast2600_i2c_remove ordering.
- remove ast2600_i2c_probe goto labels, and add dev_err_probe -remove
redundant deb_dbg debug message.
- rename gr_regmap -> global_regs
v5:
- remove ast2600-i2c-global.yaml, i2c-ast2600-global.c.
- i2c-ast2600.c
- remove legacy clock divide, all go for new clock divide.
- remove duplicated read isr.
- remove no used driver match
- fix probe return for each labels return.
- global use mfd driver, driver use phandle to regmap read/write.
- rename aspeed,i2c-ast2600.yaml to aspeed,i2cv2.yaml -remove bus-frequency.
- add required aspeed,gr
- add timeout, byte-mode, buff-mode properites.
v4:
- fix i2c-ast2600.c driver buffer mode use single buffer conflit in
master slave mode both enable.
- fix kmemleak issue when use dma mode.
- fix typo aspeed,i2c-ast2600.yaml compatible is "aspeed,ast2600-i2c"
- fix typo aspeed,i2c-ast2600.ymal to aspeed,i2c-ast2600.yaml
v3:
- fix i2c global clock divide default value.
- remove i2c slave no used dev_dbg info.
v2:
- add i2c global ymal file commit.
- rename file name from new to ast2600.
aspeed-i2c-new-global.c -> i2c-ast2600-global.c
aspeed-i2c-new-global.h -> i2c-ast2600-global.h
i2c-new-aspeed.c -> i2c-ast2600.c
- rename all driver function name to ast2600.
Ryan Chen (3):
dt-bindings: i2c: aspeed,i2c.yaml: add transfer-mode and global-regs
properties and update example
i2c: ast2600: Add controller driver for new register layout
i2c: ast2600: Add target mode support
.../devicetree/bindings/i2c/aspeed,i2c.yaml | 39 +
drivers/i2c/busses/Kconfig | 23 +-
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-ast2600.c | 1598 +++++++++++++++++
4 files changed, 1653 insertions(+), 8 deletions(-)
create mode 100644 drivers/i2c/busses/i2c-ast2600.c
--
2.34.1
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v17 1/3] dt-bindings: i2c: aspeed,i2c.yaml: add transfer-mode and global-regs properties and update example
2025-08-14 8:41 [PATCH v17 0/3] Add ASPEED AST2600 I2C controller driver Ryan Chen
@ 2025-08-14 8:41 ` Ryan Chen
2025-08-14 22:30 ` Rob Herring
2025-08-14 8:41 ` [PATCH v17 2/3] i2c: ast2600: Add controller driver for new register layout Ryan Chen
2025-08-14 8:41 ` [PATCH v17 3/3] i2c: ast2600: Add target mode support Ryan Chen
2 siblings, 1 reply; 8+ messages in thread
From: Ryan Chen @ 2025-08-14 8:41 UTC (permalink / raw)
To: ryan_chen, benh, joel, andi.shyti, robh, krzk+dt, conor+dt,
andrew, p.zabel, andriy.shevchenko, naresh.solanki, linux-i2c,
openbmc, devicetree, linux-arm-kernel, linux-aspeed, linux-kernel
- Add property "aspeed,global-regs" to get phandle set global
register, for register mode selection and clock divider control.
- Add an optional property "aspeed,transfer-mode" to
allow device tree to specify the desired transfer method used
by each I2C controller instance.
- Update example to demonstrate usage of 'aspeed,global-regs' and
'aspeed,transfer-mode' for AST2600 I2C controller.
Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
.../devicetree/bindings/i2c/aspeed,i2c.yaml | 39 +++++++++++++++++++
1 file changed, 39 insertions(+)
diff --git a/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml b/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
index 5b9bd2feda3b..2a9f7d1d2ea1 100644
--- a/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
@@ -44,6 +44,34 @@ properties:
description: frequency of the bus clock in Hz defaults to 100 kHz when not
specified
+ aspeed,transfer-mode:
+ description: |
+ ASPEED ast2600 platform equipped with 16 I2C controllers each i2c controller
+ have 1 byte transfer buffer(byte mode), 32 bytes buffer(buffer mode), and
+ share a DMA engine.
+ Select I2C transfer mode for this controller. Supported values are:
+ - "byte": Use 1 byte for i2c transmit (1-byte buffer).
+ - "buffer": Use buffer (32-byte buffer) for i2c transmit. (default)
+ Better performance then byte mode.
+ - "dma": Each controller DMA mode is shared DMA engine. The AST2600 SoC
+ provides a single DMA engine shared for 16 I2C controllers,
+ so only a limited number of controllers can use DMA simultaneously.
+ Therefore, the DTS must explicitly assign which controllers are
+ configured to use DMA.
+ Only one mode can be selected per controller.
+ On AST2600, each controller supports all three modes.
+ If not specified, buffer mode is used by default.
+ enum:
+ - byte
+ - buffer
+ - dma
+
+ aspeed,global-regs:
+ $ref: /schemas/types.yaml#/definitions/phandle
+ description: |
+ The phandle of i2c global register node, For control the i2c register
+ define selection, clock divider mode selection and clock divider control.
+
required:
- reg
- compatible
@@ -66,3 +94,14 @@ examples:
interrupts = <0>;
interrupt-parent = <&i2c_ic>;
};
+ - |
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ i2c1: i2c@80 {
+ compatible = "aspeed,ast2600-i2c-bus";
+ reg = <0x80 0x80>, <0xc00 0x20>;
+ aspeed,global-regs = <&i2c_global>;
+ clocks = <&syscon ASPEED_CLK_APB>;
+ resets = <&syscon ASPEED_RESET_I2C>;
+ interrupts = <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>;
+ aspeed,transfer-mode = "buffer";
+ };
--
2.34.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v17 2/3] i2c: ast2600: Add controller driver for new register layout
2025-08-14 8:41 [PATCH v17 0/3] Add ASPEED AST2600 I2C controller driver Ryan Chen
2025-08-14 8:41 ` [PATCH v17 1/3] dt-bindings: i2c: aspeed,i2c.yaml: add transfer-mode and global-regs properties and update example Ryan Chen
@ 2025-08-14 8:41 ` Ryan Chen
2025-08-14 10:42 ` Philipp Zabel
2025-08-14 8:41 ` [PATCH v17 3/3] i2c: ast2600: Add target mode support Ryan Chen
2 siblings, 1 reply; 8+ messages in thread
From: Ryan Chen @ 2025-08-14 8:41 UTC (permalink / raw)
To: ryan_chen, benh, joel, andi.shyti, robh, krzk+dt, conor+dt,
andrew, p.zabel, andriy.shevchenko, naresh.solanki, linux-i2c,
openbmc, devicetree, linux-arm-kernel, linux-aspeed, linux-kernel
Add i2c-ast2600 new register mode driver to support AST2600
i2c new register mode. This i2c-ast2600 new driver and the
legacy i2c-aspeed driver both match the same compatible string
"aspeed,ast2600-i2c-bus" because they target the same I2C
controller IP on AST2600. However, AST2600 SoCs may configure
the controller instances to operate either in the legacy
register layout or the new layout (via global register).
The new register mode support following.
- Add new clock divider option for more flexible and accurate
clock rate generation
- Add tCKHighMin timing to guarantee SCL high pulse width.
- Add support dual pool buffer mode, split 32 bytes pool buffer
of each device into 2 x 16 bytes for Tx and Rx individually.
- Increase DMA buffer size to 4096 bytes and support byte alignment.
- Re-define the base address of BUS1 ~ BUS16 and Pool buffer.
- Re-define registers for separating controller and target
mode control.
- Support 4 individual DMA buffers for controller Tx and Rx,
target Tx and Rx.
And following is new register set for package transfer sequence.
- New Master operation mode:
S -> Aw -> P
S -> Aw -> TxD -> P
S -> Ar -> RxD -> P
S -> Aw -> TxD -> Sr -> Ar -> RxD -> P
- Bus SDA lock auto-release capability for new controller DMA
command mode.
- Bus auto timeout for new controller/target DMA mode.
Since the register layout is selected via a global register at
runtime and both drivers bind to the same compatible string,
this patch defines the driver selection at build-time using
Kconfig, ensuring that only one driver is compiled into the
kernel. This approach avoids ambiguity and ensures consistent
behavior for each platform configuration.
The following is two versus register layout.
Old register mode:
{I2CD00}: Function Control Register
{I2CD04}: Clock and AC Timing Control Register
{I2CD08}: Clock and AC Timing Control Register
{I2CD0C}: Interrupt Control Register
{I2CD10}: Interrupt Status Register
{I2CD14}: Command/Status Register
{I2CD18}: Slave Device Address Register
{I2CD1C}: Pool Buffer Control Register
{I2CD20}: Transmit/Receive Byte Buffer Register
{I2CD24}: DMA Mode Buffer Address Register
{I2CD28}: DMA Transfer Length Register
{I2CD2C}: Original DMA Mode Buffer Address Setting
{I2CD30}: Original DMA Transfer Length Setting and Final Status
New Register mode
{I2CC00}: Master/Slave Function Control Register
{I2CC04}: Master/Slave Clock and AC Timing Control Register
{I2CC08}: Master/Slave Transmit/Receive Byte Buffer Register
{I2CC0C}: Master/Slave Pool Buffer Control Register
{I2CM10}: Master Interrupt Control Register
{I2CM14}: Master Interrupt Status Register
{I2CM18}: Master Command/Status Register
{I2CM1C}: Master DMA Buffer Length Register
{I2CS20}: Slave~ Interrupt Control Register
{I2CS24}: Slave~ Interrupt Status Register
{I2CS28}: Slave~ Command/Status Register
{I2CS2C}: Slave~ DMA Buffer Length Register
{I2CM30}: Master DMA Mode Tx Buffer Base Address
{I2CM34}: Master DMA Mode Rx Buffer Base Address
{I2CS38}: Slave~ DMA Mode Tx Buffer Base Address
{I2CS3C}: Slave~ DMA Mode Rx Buffer Base Address
{I2CS40}: Slave Device Address Register
{I2CM48}: Master DMA Length Status Register
{I2CS4C}: Slave DMA Length Status Register
{I2CC50}: Current DMA Operating Address Status
{I2CC54}: Current DMA Operating Length Status
Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
drivers/i2c/busses/Kconfig | 23 +-
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-ast2600.c | 1038 ++++++++++++++++++++++++++++++
3 files changed, 1054 insertions(+), 8 deletions(-)
create mode 100644 drivers/i2c/busses/i2c-ast2600.c
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index c8d115b58e44..6dc6f8c18eea 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -403,14 +403,21 @@ config I2C_ALTERA
will be called i2c-altera.
config I2C_ASPEED
- tristate "Aspeed I2C Controller"
- depends on ARCH_ASPEED || COMPILE_TEST
- help
- If you say yes to this option, support will be included for the
- Aspeed I2C controller.
-
- This driver can also be built as a module. If so, the module
- will be called i2c-aspeed.
+ tristate "ASPEED I2C controller (legacy register layout)"
+ depends on I2C
+ help
+ Select this to build the legacy Aspeed I2C driver (i2c-aspeed.c)
+ which uses the original mixed controller/target register layout.
+
+config I2C_AST2600
+ tristate "AST2600 I2C controller (new register layout)"
+ depends on I2C
+ depends on !I2C_ASPEED
+ help
+ Select this to build the new AST2600 I2C driver (i2c-ast2600.c)
+ supporting the separated controller/target registers and new
+ clock/divider/DMA features. This is mutually exclusive with
+ CONFIG_I2C_ASPEED.
config I2C_AT91
tristate "Atmel AT91 I2C Two-Wire interface (TWI)"
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 04db855fdfd6..eae2ffd8c62b 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_I2C_ALTERA) += i2c-altera.o
obj-$(CONFIG_I2C_AMD_MP2) += i2c-amd-mp2-pci.o i2c-amd-mp2-plat.o
obj-$(CONFIG_I2C_AMD_ASF) += i2c-amd-asf-plat.o
obj-$(CONFIG_I2C_ASPEED) += i2c-aspeed.o
+obj-$(CONFIG_I2C_AST2600) += i2c-ast2600.o
obj-$(CONFIG_I2C_AT91) += i2c-at91.o
i2c-at91-y := i2c-at91-core.o i2c-at91-master.o
i2c-at91-$(CONFIG_I2C_AT91_SLAVE_EXPERIMENTAL) += i2c-at91-slave.o
diff --git a/drivers/i2c/busses/i2c-ast2600.c b/drivers/i2c/busses/i2c-ast2600.c
new file mode 100644
index 000000000000..15e600ff50ec
--- /dev/null
+++ b/drivers/i2c/busses/i2c-ast2600.c
@@ -0,0 +1,1038 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ASPEED AST2600 new register set I2C controller driver
+ *
+ * Copyright (C) ASPEED Technology Inc.
+ */
+#include <linux/array_size.h>
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/minmax.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+#include <linux/string_helpers.h>
+#include <linux/unaligned.h>
+
+#define AST2600_I2CG_ISR 0x00
+#define AST2600_I2CG_SLAVE_ISR 0x04
+#define AST2600_I2CG_OWNER 0x08
+#define AST2600_I2CG_CTRL 0x0C
+#define AST2600_I2CG_CLK_DIV_CTRL 0x10
+
+#define AST2600_I2CG_SLAVE_PKT_NAK BIT(4)
+#define AST2600_I2CG_M_S_SEPARATE_INTR BIT(3)
+#define AST2600_I2CG_CTRL_NEW_REG BIT(2)
+#define AST2600_I2CG_CTRL_NEW_CLK_DIV BIT(1)
+#define AST2600_GLOBAL_INIT \
+ (AST2600_I2CG_CTRL_NEW_REG | AST2600_I2CG_CTRL_NEW_CLK_DIV)
+/*
+ * APB clk : 100Mhz
+ * div : scl : baseclk [APB/((div/2) + 1)] : tBuf [1/bclk * 16]
+ * I2CG10[31:24] base clk4 for i2c auto recovery timeout counter (0xC6)
+ * I2CG10[23:16] base clk3 for Standard-mode (100Khz) min tBuf 4.7us
+ * 0x3c : 100.8Khz : 3.225Mhz : 4.96us
+ * 0x3d : 99.2Khz : 3.174Mhz : 5.04us
+ * 0x3e : 97.65Khz : 3.125Mhz : 5.12us
+ * 0x40 : 97.75Khz : 3.03Mhz : 5.28us
+ * 0x41 : 99.5Khz : 2.98Mhz : 5.36us (default)
+ * I2CG10[15:8] base clk2 for Fast-mode (400Khz) min tBuf 1.3us
+ * 0x12 : 400Khz : 10Mhz : 1.6us
+ * I2CG10[7:0] base clk1 for Fast-mode Plus (1Mhz) min tBuf 0.5us
+ * 0x08 : 1Mhz : 20Mhz : 0.8us
+ */
+#define I2CCG_DIV_CTRL 0xC6411208
+
+/* 0x00 : I2CC Controller/Target Function Control Register */
+#define AST2600_I2CC_FUN_CTRL 0x00
+#define AST2600_I2CC_SLAVE_ADDR_RX_EN BIT(20)
+#define AST2600_I2CC_MASTER_RETRY_MASK GENMASK(19, 18)
+#define AST2600_I2CC_MASTER_RETRY(x) (((x) & GENMASK(1, 0)) << 18)
+#define AST2600_I2CC_BUS_AUTO_RELEASE BIT(17)
+#define AST2600_I2CC_M_SDA_LOCK_EN BIT(16)
+#define AST2600_I2CC_MULTI_MASTER_DIS BIT(15)
+#define AST2600_I2CC_M_SCL_DRIVE_EN BIT(14)
+#define AST2600_I2CC_MSB_STS BIT(9)
+#define AST2600_I2CC_SDA_DRIVE_1T_EN BIT(8)
+#define AST2600_I2CC_M_SDA_DRIVE_1T_EN BIT(7)
+#define AST2600_I2CC_M_HIGH_SPEED_EN BIT(6)
+/* reserver 5 : 2 */
+#define AST2600_I2CC_SLAVE_EN BIT(1)
+#define AST2600_I2CC_MASTER_EN BIT(0)
+
+/* 0x04 : I2CC Controller/Target Clock and AC Timing Control Register #1 */
+#define AST2600_I2CC_AC_TIMING 0x04
+#define AST2600_I2CC_TTIMEOUT(x) (((x) & GENMASK(4, 0)) << 24)
+#define AST2600_I2CC_TCKHIGHMIN(x) (((x) & GENMASK(3, 0)) << 20)
+#define AST2600_I2CC_TCKHIGH(x) (((x) & GENMASK(3, 0)) << 16)
+#define AST2600_I2CC_TCKLOW(x) (((x) & GENMASK(3, 0)) << 12)
+#define AST2600_I2CC_THDDAT(x) (((x) & GENMASK(1, 0)) << 10)
+#define AST2600_I2CC_TOUTBASECLK(x) (((x) & GENMASK(1, 0)) << 8)
+#define AST2600_I2CC_TBASECLK(x) ((x) & GENMASK(3, 0))
+
+/* 0x08 : I2CC Controller/Target Transmit/Receive Byte Buffer Register */
+#define AST2600_I2CC_STS_AND_BUFF 0x08
+#define AST2600_I2CC_TX_DIR_MASK GENMASK(31, 29)
+#define AST2600_I2CC_SDA_OE BIT(28)
+#define AST2600_I2CC_SDA_O BIT(27)
+#define AST2600_I2CC_SCL_OE BIT(26)
+#define AST2600_I2CC_SCL_O BIT(25)
+
+#define AST2600_I2CC_SCL_LINE_STS BIT(18)
+#define AST2600_I2CC_SDA_LINE_STS BIT(17)
+#define AST2600_I2CC_BUS_BUSY_STS BIT(16)
+
+#define AST2600_I2CC_GET_RX_BUFF(x) (((x) >> 8) & GENMASK(7, 0))
+
+/* 0x0C : I2CC Controller/Target Pool Buffer Control Register */
+#define AST2600_I2CC_BUFF_CTRL 0x0C
+#define AST2600_I2CC_GET_RX_BUF_LEN(x) (((x) & GENMASK(29, 24)) >> 24)
+#define AST2600_I2CC_SET_RX_BUF_LEN(x) (((((x) - 1) & GENMASK(4, 0)) << 16) | BIT(0))
+#define AST2600_I2CC_SET_TX_BUF_LEN(x) (((((x) - 1) & GENMASK(4, 0)) << 8) | BIT(0))
+#define AST2600_I2CC_GET_TX_BUF_LEN(x) ((((x) & GENMASK(12, 8)) >> 8) + 1)
+
+/* 0x10 : I2CM Controller Interrupt Control Register */
+#define AST2600_I2CM_IER 0x10
+/* 0x14 : I2CM Controller Interrupt Status Register : WC */
+#define AST2600_I2CM_ISR 0x14
+
+#define AST2600_I2CM_PKT_TIMEOUT BIT(18)
+#define AST2600_I2CM_PKT_ERROR BIT(17)
+#define AST2600_I2CM_PKT_DONE BIT(16)
+
+#define AST2600_I2CM_BUS_RECOVER_FAIL BIT(15)
+#define AST2600_I2CM_SDA_DL_TO BIT(14)
+#define AST2600_I2CM_BUS_RECOVER BIT(13)
+#define AST2600_I2CM_SMBUS_ALT BIT(12)
+
+#define AST2600_I2CM_SCL_LOW_TO BIT(6)
+#define AST2600_I2CM_ABNORMAL BIT(5)
+#define AST2600_I2CM_NORMAL_STOP BIT(4)
+#define AST2600_I2CM_ARBIT_LOSS BIT(3)
+#define AST2600_I2CM_RX_DONE BIT(2)
+#define AST2600_I2CM_TX_NAK BIT(1)
+#define AST2600_I2CM_TX_ACK BIT(0)
+
+/* 0x18 : I2CM Controller Command/Status Register */
+#define AST2600_I2CM_CMD_STS 0x18
+#define AST2600_I2CM_PKT_ADDR(x) (((x) & GENMASK(6, 0)) << 24)
+#define AST2600_I2CM_PKT_EN BIT(16)
+#define AST2600_I2CM_SDA_OE_OUT_DIR BIT(15)
+#define AST2600_I2CM_SDA_O_OUT_DIR BIT(14)
+#define AST2600_I2CM_SCL_OE_OUT_DIR BIT(13)
+#define AST2600_I2CM_SCL_O_OUT_DIR BIT(12)
+#define AST2600_I2CM_RECOVER_CMD_EN BIT(11)
+
+#define AST2600_I2CM_RX_DMA_EN BIT(9)
+#define AST2600_I2CM_TX_DMA_EN BIT(8)
+/* Command Bit */
+#define AST2600_I2CM_RX_BUFF_EN BIT(7)
+#define AST2600_I2CM_TX_BUFF_EN BIT(6)
+#define AST2600_I2CM_STOP_CMD BIT(5)
+#define AST2600_I2CM_RX_CMD_LAST BIT(4)
+#define AST2600_I2CM_RX_CMD BIT(3)
+
+#define AST2600_I2CM_TX_CMD BIT(1)
+#define AST2600_I2CM_START_CMD BIT(0)
+
+/* 0x1C : I2CM Controller DMA Transfer Length Register */
+#define AST2600_I2CM_DMA_LEN 0x1C
+/* Tx Rx support length 1 ~ 4096 */
+#define AST2600_I2CM_SET_RX_DMA_LEN(x) ((((x) & GENMASK(11, 0)) << 16) | BIT(31))
+#define AST2600_I2CM_SET_TX_DMA_LEN(x) (((x) & GENMASK(11, 0)) | BIT(15))
+
+/* 0x20 : I2CS Target Interrupt Control Register */
+#define AST2600_I2CS_IER 0x20
+/* 0x24 : I2CS Target Interrupt Status Register */
+#define AST2600_I2CS_ISR 0x24
+
+#define AST2600_I2CS_ADDR_INDICATE_MASK GENMASK(31, 30)
+#define AST2600_I2CS_SLAVE_PENDING BIT(29)
+
+#define AST2600_I2CS_WAIT_TX_DMA BIT(25)
+#define AST2600_I2CS_WAIT_RX_DMA BIT(24)
+
+#define AST2600_I2CS_ADDR3_NAK BIT(22)
+#define AST2600_I2CS_ADDR2_NAK BIT(21)
+#define AST2600_I2CS_ADDR1_NAK BIT(20)
+
+#define AST2600_I2CS_ADDR_MASK GENMASK(19, 18)
+#define AST2600_I2CS_PKT_ERROR BIT(17)
+#define AST2600_I2CS_PKT_DONE BIT(16)
+#define AST2600_I2CS_INACTIVE_TO BIT(15)
+
+#define AST2600_I2CS_SLAVE_MATCH BIT(7)
+#define AST2600_I2CS_ABNOR_STOP BIT(5)
+#define AST2600_I2CS_STOP BIT(4)
+#define AST2600_I2CS_RX_DONE_NAK BIT(3)
+#define AST2600_I2CS_RX_DONE BIT(2)
+#define AST2600_I2CS_TX_NAK BIT(1)
+#define AST2600_I2CS_TX_ACK BIT(0)
+
+/* 0x28 : I2CS Target CMD/Status Register */
+#define AST2600_I2CS_CMD_STS 0x28
+#define AST2600_I2CS_ACTIVE_ALL GENMASK(18, 17)
+#define AST2600_I2CS_PKT_MODE_EN BIT(16)
+#define AST2600_I2CS_AUTO_NAK_NOADDR BIT(15)
+#define AST2600_I2CS_AUTO_NAK_EN BIT(14)
+
+#define AST2600_I2CS_ALT_EN BIT(10)
+#define AST2600_I2CS_RX_DMA_EN BIT(9)
+#define AST2600_I2CS_TX_DMA_EN BIT(8)
+#define AST2600_I2CS_RX_BUFF_EN BIT(7)
+#define AST2600_I2CS_TX_BUFF_EN BIT(6)
+#define AST2600_I2CS_RX_CMD_LAST BIT(4)
+
+#define AST2600_I2CS_TX_CMD BIT(2)
+
+#define AST2600_I2CS_DMA_LEN 0x2C
+#define AST2600_I2CS_SET_RX_DMA_LEN(x) (((((x) - 1) & GENMASK(11, 0)) << 16) | BIT(31))
+#define AST2600_I2CS_SET_TX_DMA_LEN(x) ((((x) - 1) & GENMASK(11, 0)) | BIT(15))
+
+/* I2CM Controller DMA Tx Buffer Register */
+#define AST2600_I2CM_TX_DMA 0x30
+/* I2CM Controller DMA Rx Buffer Register */
+#define AST2600_I2CM_RX_DMA 0x34
+/* I2CS Target DMA Tx Buffer Register */
+#define AST2600_I2CS_TX_DMA 0x38
+/* I2CS Target DMA Rx Buffer Register */
+#define AST2600_I2CS_RX_DMA 0x3C
+
+#define AST2600_I2CS_ADDR_CTRL 0x40
+
+#define AST2600_I2CS_ADDR3_MASK GENMASK(22, 16)
+#define AST2600_I2CS_ADDR2_MASK GENMASK(14, 8)
+#define AST2600_I2CS_ADDR1_MASK GENMASK(6, 0)
+
+#define AST2600_I2CM_DMA_LEN_STS 0x48
+#define AST2600_I2CS_DMA_LEN_STS 0x4C
+
+#define AST2600_I2C_GET_TX_DMA_LEN(x) ((x) & GENMASK(12, 0))
+#define AST2600_I2C_GET_RX_DMA_LEN(x) (((x) & GENMASK(28, 16)) >> 16)
+
+/* 0x40 : Target Device Address Register */
+#define AST2600_I2CS_ADDR3_ENABLE BIT(23)
+#define AST2600_I2CS_ADDR3(x) ((x) << 16)
+#define AST2600_I2CS_ADDR2_ENABLE BIT(15)
+#define AST2600_I2CS_ADDR2(x) ((x) << 8)
+#define AST2600_I2CS_ADDR1_ENABLE BIT(7)
+#define AST2600_I2CS_ADDR1(x) (x)
+
+#define I2C_TARGET_MSG_BUF_SIZE 256
+
+#define AST2600_I2C_DMA_SIZE 4096
+
+#define CONTROLLER_TRIGGER_LAST_STOP (AST2600_I2CM_RX_CMD_LAST | AST2600_I2CM_STOP_CMD)
+#define TARGET_TRIGGER_CMD (AST2600_I2CS_ACTIVE_ALL | AST2600_I2CS_PKT_MODE_EN)
+
+#define AST_I2C_TIMEOUT_CLK 0x1
+
+enum xfer_mode {
+ BYTE_MODE,
+ BUFF_MODE,
+ DMA_MODE,
+};
+
+struct ast2600_i2c_bus {
+ struct i2c_adapter adap;
+ struct device *dev;
+ void __iomem *reg_base;
+ struct regmap *global_regs;
+ struct reset_control *rst;
+ struct clk *clk;
+ struct i2c_timings timing_info;
+ struct completion cmd_complete;
+ struct i2c_msg *msgs;
+ u8 *controller_dma_safe_buf;
+ dma_addr_t controller_dma_addr;
+ u32 apb_clk;
+ u32 timeout;
+ int irq;
+ int cmd_err;
+ int msgs_index;
+ int msgs_count;
+ int controller_xfer_cnt;
+ size_t buf_index;
+ size_t buf_size;
+ enum xfer_mode mode;
+ bool multi_master;
+ /* Buffer mode */
+ void __iomem *buf_base;
+ struct i2c_smbus_alert_setup alert_data;
+};
+
+static u32 ast2600_select_i2c_clock(struct ast2600_i2c_bus *i2c_bus)
+{
+ unsigned long base_clk[16];
+ int baseclk_idx = 0;
+ int divisor = 0;
+ u32 clk_div_reg;
+ u32 scl_low;
+ u32 scl_high;
+ u32 data;
+
+ regmap_read(i2c_bus->global_regs, AST2600_I2CG_CLK_DIV_CTRL, &clk_div_reg);
+
+ for (int i = 0; i < ARRAY_SIZE(base_clk); i++) {
+ if (i == 0)
+ base_clk[i] = i2c_bus->apb_clk;
+ else if (i < 5)
+ base_clk[i] = (i2c_bus->apb_clk * 2) /
+ (((clk_div_reg >> ((i - 1) * 8)) & GENMASK(7, 0)) + 2);
+ else
+ base_clk[i] = base_clk[4] >> (i - 4);
+
+ if ((base_clk[i] / i2c_bus->timing_info.bus_freq_hz) <= 32) {
+ baseclk_idx = i;
+ divisor = DIV_ROUND_UP(base_clk[i], i2c_bus->timing_info.bus_freq_hz);
+ break;
+ }
+ }
+ baseclk_idx = min(baseclk_idx, 15);
+ divisor = min(divisor, 32);
+ scl_low = min(divisor * 9 / 16 - 1, 15);
+ scl_high = (divisor - scl_low - 2) & GENMASK(3, 0);
+ data = (scl_high - 1) << 20 | scl_high << 16 | scl_low << 12 | baseclk_idx;
+ if (i2c_bus->timeout) {
+ data |= AST2600_I2CC_TOUTBASECLK(AST_I2C_TIMEOUT_CLK);
+ data |= AST2600_I2CC_TTIMEOUT(i2c_bus->timeout);
+ }
+
+ return data;
+}
+
+static int ast2600_i2c_recover_bus(struct ast2600_i2c_bus *i2c_bus)
+{
+ u32 state = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
+ int ret = 0;
+ u32 ctrl;
+ int r;
+
+ dev_dbg(i2c_bus->dev, "%d-bus recovery bus [%x]\n", i2c_bus->adap.nr, state);
+
+ ctrl = readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+
+ /* Disable controller */
+ writel(ctrl & ~(AST2600_I2CC_MASTER_EN | AST2600_I2CC_SLAVE_EN),
+ i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+
+ writel(readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL) | AST2600_I2CC_MASTER_EN,
+ i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+
+ reinit_completion(&i2c_bus->cmd_complete);
+ i2c_bus->cmd_err = 0;
+
+ /* Check 0x14's SDA and SCL status */
+ state = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
+ if (!(state & AST2600_I2CC_SDA_LINE_STS) && (state & AST2600_I2CC_SCL_LINE_STS)) {
+ writel(AST2600_I2CM_RECOVER_CMD_EN, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+ r = wait_for_completion_timeout(&i2c_bus->cmd_complete, i2c_bus->adap.timeout);
+ if (r == 0) {
+ dev_dbg(i2c_bus->dev, "recovery timed out\n");
+ writel(ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ return -ETIMEDOUT;
+ } else if (i2c_bus->cmd_err) {
+ dev_dbg(i2c_bus->dev, "recovery error\n");
+ ret = -EPROTO;
+ }
+ }
+
+ /* Recovery done */
+ state = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
+ if (state & AST2600_I2CC_BUS_BUSY_STS) {
+ dev_dbg(i2c_bus->dev, "Can't recover bus [%x]\n", state);
+ ret = -EPROTO;
+ }
+
+ /* restore original controller setting */
+ writel(ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ return ret;
+}
+
+static int ast2600_i2c_setup_dma_tx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+ int xfer_len = msg->len - i2c_bus->controller_xfer_cnt;
+ int ret;
+
+ cmd |= AST2600_I2CM_PKT_EN;
+
+ if (xfer_len > AST2600_I2C_DMA_SIZE)
+ xfer_len = AST2600_I2C_DMA_SIZE;
+ else if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count)
+ cmd |= AST2600_I2CM_STOP_CMD;
+
+ if (cmd & AST2600_I2CM_START_CMD) {
+ cmd |= AST2600_I2CM_PKT_ADDR(msg->addr);
+ if (xfer_len) {
+ i2c_bus->controller_dma_safe_buf = i2c_get_dma_safe_msg_buf(msg, 1);
+ if (!i2c_bus->controller_dma_safe_buf)
+ return -ENOMEM;
+ i2c_bus->controller_dma_addr =
+ dma_map_single(i2c_bus->dev, i2c_bus->controller_dma_safe_buf,
+ msg->len, DMA_TO_DEVICE);
+ ret = dma_mapping_error(i2c_bus->dev, i2c_bus->controller_dma_addr);
+ if (ret) {
+ i2c_put_dma_safe_msg_buf(i2c_bus->controller_dma_safe_buf, msg,
+ false);
+ i2c_bus->controller_dma_safe_buf = NULL;
+ return ret;
+ }
+ }
+ }
+
+ if (xfer_len) {
+ cmd |= AST2600_I2CM_TX_DMA_EN | AST2600_I2CM_TX_CMD;
+ writel(AST2600_I2CM_SET_TX_DMA_LEN(xfer_len - 1),
+ i2c_bus->reg_base + AST2600_I2CM_DMA_LEN);
+ writel(i2c_bus->controller_dma_addr + i2c_bus->controller_xfer_cnt,
+ i2c_bus->reg_base + AST2600_I2CM_TX_DMA);
+ }
+
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+
+ return 0;
+}
+
+static int ast2600_i2c_setup_buff_tx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+ int xfer_len = msg->len - i2c_bus->controller_xfer_cnt;
+ u32 wbuf_dword;
+ int i;
+
+ cmd |= AST2600_I2CM_PKT_EN;
+
+ if (xfer_len > i2c_bus->buf_size)
+ xfer_len = i2c_bus->buf_size;
+ else if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count)
+ cmd |= AST2600_I2CM_STOP_CMD;
+
+ if (cmd & AST2600_I2CM_START_CMD)
+ cmd |= AST2600_I2CM_PKT_ADDR(msg->addr);
+
+ if (xfer_len) {
+ cmd |= AST2600_I2CM_TX_BUFF_EN | AST2600_I2CM_TX_CMD;
+ /*
+ * The controller's buffer register supports dword writes only.
+ * Therefore, write dwords to the buffer register in a 4-byte aligned,
+ * and write the remaining unaligned data at the end.
+ */
+ for (i = 0; i < xfer_len; i += 4) {
+ int xfer_cnt = i2c_bus->controller_xfer_cnt + i;
+
+ switch (min(xfer_len - i, 4) % 4) {
+ case 1:
+ wbuf_dword = msg->buf[xfer_cnt];
+ break;
+ case 2:
+ wbuf_dword = get_unaligned_le16(&msg->buf[xfer_cnt]);
+ break;
+ case 3:
+ wbuf_dword = get_unaligned_le24(&msg->buf[xfer_cnt]);
+ break;
+ default:
+ wbuf_dword = get_unaligned_le32(&msg->buf[xfer_cnt]);
+ break;
+ }
+ writel(wbuf_dword, i2c_bus->buf_base + i);
+ }
+ writel(AST2600_I2CC_SET_TX_BUF_LEN(xfer_len),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ }
+
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+
+ return 0;
+}
+
+static int ast2600_i2c_setup_byte_tx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+ int xfer_len;
+
+ xfer_len = msg->len - i2c_bus->controller_xfer_cnt;
+
+ cmd |= AST2600_I2CM_PKT_EN;
+
+ if (cmd & AST2600_I2CM_START_CMD)
+ cmd |= AST2600_I2CM_PKT_ADDR(msg->addr);
+
+ if ((i2c_bus->msgs_index + 1 == i2c_bus->msgs_count) &&
+ ((i2c_bus->controller_xfer_cnt + 1) == msg->len))
+ cmd |= AST2600_I2CM_STOP_CMD;
+
+ if (xfer_len) {
+ cmd |= AST2600_I2CM_TX_CMD;
+ writel(msg->buf[i2c_bus->controller_xfer_cnt],
+ i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
+ }
+
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+
+ return 0;
+}
+
+static int ast2600_i2c_setup_dma_rx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+ int xfer_len = msg->len - i2c_bus->controller_xfer_cnt;
+ int ret;
+
+ cmd |= AST2600_I2CM_PKT_EN | AST2600_I2CM_RX_DMA_EN | AST2600_I2CM_RX_CMD;
+
+ if (msg->flags & I2C_M_RECV_LEN)
+ xfer_len = 1;
+ else if (xfer_len > AST2600_I2C_DMA_SIZE)
+ xfer_len = AST2600_I2C_DMA_SIZE;
+ else if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count)
+ cmd |= CONTROLLER_TRIGGER_LAST_STOP;
+
+ writel(AST2600_I2CM_SET_RX_DMA_LEN(xfer_len - 1), i2c_bus->reg_base + AST2600_I2CM_DMA_LEN);
+
+ if (cmd & AST2600_I2CM_START_CMD) {
+ cmd |= AST2600_I2CM_PKT_ADDR(msg->addr);
+ i2c_bus->controller_dma_safe_buf = i2c_get_dma_safe_msg_buf(msg, 1);
+ if (!i2c_bus->controller_dma_safe_buf)
+ return -ENOMEM;
+ if (msg->flags & I2C_M_RECV_LEN)
+ i2c_bus->controller_dma_addr =
+ dma_map_single(i2c_bus->dev, i2c_bus->controller_dma_safe_buf,
+ I2C_SMBUS_BLOCK_MAX + 3, DMA_FROM_DEVICE);
+ else
+ i2c_bus->controller_dma_addr =
+ dma_map_single(i2c_bus->dev, i2c_bus->controller_dma_safe_buf,
+ msg->len, DMA_FROM_DEVICE);
+ ret = dma_mapping_error(i2c_bus->dev, i2c_bus->controller_dma_addr);
+ if (ret) {
+ i2c_put_dma_safe_msg_buf(i2c_bus->controller_dma_safe_buf, msg, false);
+ i2c_bus->controller_dma_safe_buf = NULL;
+ return -ENOMEM;
+ }
+ }
+ writel(i2c_bus->controller_dma_addr, i2c_bus->reg_base + AST2600_I2CM_RX_DMA);
+
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+
+ return 0;
+}
+
+static int ast2600_i2c_setup_buff_rx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+ int xfer_len = msg->len - i2c_bus->controller_xfer_cnt;
+
+ cmd |= AST2600_I2CM_PKT_EN | AST2600_I2CM_RX_BUFF_EN | AST2600_I2CM_RX_CMD;
+
+ if (cmd & AST2600_I2CM_START_CMD)
+ cmd |= AST2600_I2CM_PKT_ADDR(msg->addr);
+
+ if (msg->flags & I2C_M_RECV_LEN) {
+ dev_dbg(i2c_bus->dev, "smbus read\n");
+ xfer_len = 1;
+ } else if (xfer_len > i2c_bus->buf_size) {
+ xfer_len = i2c_bus->buf_size;
+ } else if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count) {
+ cmd |= CONTROLLER_TRIGGER_LAST_STOP;
+ }
+ writel(AST2600_I2CC_SET_RX_BUF_LEN(xfer_len), i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+
+ return 0;
+}
+
+static int ast2600_i2c_setup_byte_rx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+
+ cmd |= AST2600_I2CM_PKT_EN | AST2600_I2CM_RX_CMD;
+
+ if (cmd & AST2600_I2CM_START_CMD)
+ cmd |= AST2600_I2CM_PKT_ADDR(msg->addr);
+
+ if (msg->flags & I2C_M_RECV_LEN) {
+ dev_dbg(i2c_bus->dev, "smbus read\n");
+ } else if ((i2c_bus->msgs_index + 1 == i2c_bus->msgs_count) &&
+ ((i2c_bus->controller_xfer_cnt + 1) == msg->len)) {
+ cmd |= CONTROLLER_TRIGGER_LAST_STOP;
+ }
+
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+
+ return 0;
+}
+
+static int ast2600_i2c_do_start(struct ast2600_i2c_bus *i2c_bus)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+
+ /* send start */
+ dev_dbg(i2c_bus->dev, "[%d] %s %d byte%s %s 0x%02x\n",
+ i2c_bus->msgs_index, str_read_write(msg->flags & I2C_M_RD),
+ msg->len, str_plural(msg->len),
+ msg->flags & I2C_M_RD ? "from" : "to", msg->addr);
+
+ i2c_bus->controller_xfer_cnt = 0;
+ i2c_bus->buf_index = 0;
+
+ if (msg->flags & I2C_M_RD) {
+ if (i2c_bus->mode == DMA_MODE)
+ return ast2600_i2c_setup_dma_rx(AST2600_I2CM_START_CMD, i2c_bus);
+ else if (i2c_bus->mode == BUFF_MODE)
+ return ast2600_i2c_setup_buff_rx(AST2600_I2CM_START_CMD, i2c_bus);
+ else
+ return ast2600_i2c_setup_byte_rx(AST2600_I2CM_START_CMD, i2c_bus);
+ } else {
+ if (i2c_bus->mode == DMA_MODE)
+ return ast2600_i2c_setup_dma_tx(AST2600_I2CM_START_CMD, i2c_bus);
+ else if (i2c_bus->mode == BUFF_MODE)
+ return ast2600_i2c_setup_buff_tx(AST2600_I2CM_START_CMD, i2c_bus);
+ else
+ return ast2600_i2c_setup_byte_tx(AST2600_I2CM_START_CMD, i2c_bus);
+ }
+}
+
+static int ast2600_i2c_irq_err_to_errno(u32 irq_status)
+{
+ if (irq_status & AST2600_I2CM_ARBIT_LOSS)
+ return -EAGAIN;
+ if (irq_status & (AST2600_I2CM_SDA_DL_TO | AST2600_I2CM_SCL_LOW_TO))
+ return -EBUSY;
+ if (irq_status & (AST2600_I2CM_ABNORMAL))
+ return -EPROTO;
+
+ return 0;
+}
+
+static void ast2600_i2c_controller_package_irq(struct ast2600_i2c_bus *i2c_bus, u32 sts)
+{
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+ int xfer_len;
+ int i;
+
+ sts &= ~AST2600_I2CM_PKT_DONE;
+ writel(AST2600_I2CM_PKT_DONE, i2c_bus->reg_base + AST2600_I2CM_ISR);
+ switch (sts) {
+ case AST2600_I2CM_PKT_ERROR:
+ i2c_bus->cmd_err = -EAGAIN;
+ complete(&i2c_bus->cmd_complete);
+ break;
+ case AST2600_I2CM_PKT_ERROR | AST2600_I2CM_TX_NAK: /* a0 fix for issue */
+ fallthrough;
+ case AST2600_I2CM_PKT_ERROR | AST2600_I2CM_TX_NAK | AST2600_I2CM_NORMAL_STOP:
+ i2c_bus->cmd_err = -ENXIO;
+ complete(&i2c_bus->cmd_complete);
+ break;
+ case AST2600_I2CM_NORMAL_STOP:
+ /* write 0 byte only have stop isr */
+ i2c_bus->msgs_index++;
+ if (i2c_bus->msgs_index < i2c_bus->msgs_count) {
+ if (ast2600_i2c_do_start(i2c_bus)) {
+ i2c_bus->cmd_err = -ENOMEM;
+ complete(&i2c_bus->cmd_complete);
+ }
+ } else {
+ i2c_bus->cmd_err = i2c_bus->msgs_index;
+ complete(&i2c_bus->cmd_complete);
+ }
+ break;
+ case AST2600_I2CM_TX_ACK:
+ case AST2600_I2CM_TX_ACK | AST2600_I2CM_NORMAL_STOP:
+ if (i2c_bus->mode == DMA_MODE)
+ xfer_len = AST2600_I2C_GET_TX_DMA_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CM_DMA_LEN_STS));
+ else if (i2c_bus->mode == BUFF_MODE)
+ xfer_len = AST2600_I2CC_GET_TX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ else
+ xfer_len = 1;
+
+ i2c_bus->controller_xfer_cnt += xfer_len;
+
+ if (i2c_bus->controller_xfer_cnt == msg->len) {
+ if (i2c_bus->mode == DMA_MODE) {
+ dma_unmap_single(i2c_bus->dev, i2c_bus->controller_dma_addr,
+ msg->len, DMA_TO_DEVICE);
+ i2c_put_dma_safe_msg_buf(i2c_bus->controller_dma_safe_buf, msg,
+ true);
+ i2c_bus->controller_dma_safe_buf = NULL;
+ }
+ i2c_bus->msgs_index++;
+ if (i2c_bus->msgs_index == i2c_bus->msgs_count) {
+ i2c_bus->cmd_err = i2c_bus->msgs_index;
+ complete(&i2c_bus->cmd_complete);
+ } else {
+ if (ast2600_i2c_do_start(i2c_bus)) {
+ i2c_bus->cmd_err = -ENOMEM;
+ complete(&i2c_bus->cmd_complete);
+ }
+ }
+ } else {
+ if (i2c_bus->mode == DMA_MODE)
+ ast2600_i2c_setup_dma_tx(0, i2c_bus);
+ else if (i2c_bus->mode == BUFF_MODE)
+ ast2600_i2c_setup_buff_tx(0, i2c_bus);
+ else
+ ast2600_i2c_setup_byte_tx(0, i2c_bus);
+ }
+ break;
+ case AST2600_I2CM_RX_DONE:
+ case AST2600_I2CM_RX_DONE | AST2600_I2CM_NORMAL_STOP:
+ /* do next rx */
+ if (i2c_bus->mode == DMA_MODE) {
+ xfer_len = AST2600_I2C_GET_RX_DMA_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CM_DMA_LEN_STS));
+ } else if (i2c_bus->mode == BUFF_MODE) {
+ xfer_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < xfer_len; i++)
+ msg->buf[i2c_bus->controller_xfer_cnt + i] =
+ readb(i2c_bus->buf_base + 0x10 + i);
+ } else {
+ xfer_len = 1;
+ msg->buf[i2c_bus->controller_xfer_cnt] =
+ AST2600_I2CC_GET_RX_BUFF(readl(i2c_bus->reg_base +
+ AST2600_I2CC_STS_AND_BUFF));
+ }
+
+ if (msg->flags & I2C_M_RECV_LEN) {
+ u8 recv_len = AST2600_I2CC_GET_RX_BUFF(readl(i2c_bus->reg_base
+ + AST2600_I2CC_STS_AND_BUFF));
+ msg->len = min_t(unsigned int, recv_len, I2C_SMBUS_BLOCK_MAX);
+ msg->len += ((msg->flags & I2C_CLIENT_PEC) ? 2 : 1);
+ msg->flags &= ~I2C_M_RECV_LEN;
+ if (!recv_len)
+ i2c_bus->controller_xfer_cnt = 0;
+ else
+ i2c_bus->controller_xfer_cnt = 1;
+ } else {
+ i2c_bus->controller_xfer_cnt += xfer_len;
+ }
+
+ if (i2c_bus->controller_xfer_cnt == msg->len) {
+ if (i2c_bus->mode == DMA_MODE) {
+ dma_unmap_single(i2c_bus->dev, i2c_bus->controller_dma_addr,
+ msg->len, DMA_FROM_DEVICE);
+ i2c_put_dma_safe_msg_buf(i2c_bus->controller_dma_safe_buf,
+ msg, true);
+ i2c_bus->controller_dma_safe_buf = NULL;
+ }
+
+ i2c_bus->msgs_index++;
+ if (i2c_bus->msgs_index == i2c_bus->msgs_count) {
+ i2c_bus->cmd_err = i2c_bus->msgs_index;
+ complete(&i2c_bus->cmd_complete);
+ } else {
+ if (ast2600_i2c_do_start(i2c_bus)) {
+ i2c_bus->cmd_err = -ENOMEM;
+ complete(&i2c_bus->cmd_complete);
+ }
+ }
+ } else {
+ if (i2c_bus->mode == DMA_MODE)
+ ast2600_i2c_setup_dma_rx(0, i2c_bus);
+ else if (i2c_bus->mode == BUFF_MODE)
+ ast2600_i2c_setup_buff_rx(0, i2c_bus);
+ else
+ ast2600_i2c_setup_byte_rx(0, i2c_bus);
+ }
+ break;
+ default:
+ dev_dbg(i2c_bus->dev, "unhandled sts %x\n", sts);
+ break;
+ }
+}
+
+static int ast2600_i2c_controller_irq(struct ast2600_i2c_bus *i2c_bus)
+{
+ u32 sts = readl(i2c_bus->reg_base + AST2600_I2CM_ISR);
+ u32 ctrl;
+
+ sts &= ~AST2600_I2CM_SMBUS_ALT;
+
+ if (AST2600_I2CM_BUS_RECOVER_FAIL & sts) {
+ writel(AST2600_I2CM_BUS_RECOVER_FAIL, i2c_bus->reg_base + AST2600_I2CM_ISR);
+ ctrl = readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ i2c_bus->cmd_err = -EPROTO;
+ complete(&i2c_bus->cmd_complete);
+ return 1;
+ }
+
+ if (AST2600_I2CM_BUS_RECOVER & sts) {
+ writel(AST2600_I2CM_BUS_RECOVER, i2c_bus->reg_base + AST2600_I2CM_ISR);
+ i2c_bus->cmd_err = 0;
+ complete(&i2c_bus->cmd_complete);
+ return 1;
+ }
+
+ i2c_bus->cmd_err = ast2600_i2c_irq_err_to_errno(sts);
+ if (i2c_bus->cmd_err) {
+ writel(AST2600_I2CM_PKT_DONE, i2c_bus->reg_base + AST2600_I2CM_ISR);
+ complete(&i2c_bus->cmd_complete);
+ return 1;
+ }
+
+ if (AST2600_I2CM_PKT_DONE & sts) {
+ ast2600_i2c_controller_package_irq(i2c_bus, sts);
+ return 1;
+ }
+
+ return 0;
+}
+
+static irqreturn_t ast2600_i2c_bus_irq(int irq, void *dev_id)
+{
+ struct ast2600_i2c_bus *i2c_bus = dev_id;
+
+ return IRQ_RETVAL(ast2600_i2c_controller_irq(i2c_bus));
+}
+
+static int ast2600_i2c_controller_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ struct ast2600_i2c_bus *i2c_bus = i2c_get_adapdata(adap);
+ unsigned long timeout;
+ int ret;
+
+ if (!i2c_bus->multi_master &&
+ (readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF) & AST2600_I2CC_BUS_BUSY_STS)) {
+ ret = ast2600_i2c_recover_bus(i2c_bus);
+ if (ret)
+ return ret;
+ }
+
+ i2c_bus->cmd_err = 0;
+ i2c_bus->msgs = msgs;
+ i2c_bus->msgs_index = 0;
+ i2c_bus->msgs_count = num;
+ reinit_completion(&i2c_bus->cmd_complete);
+ ret = ast2600_i2c_do_start(i2c_bus);
+ if (ret)
+ goto controller_out;
+ timeout = wait_for_completion_timeout(&i2c_bus->cmd_complete, i2c_bus->adap.timeout);
+ if (timeout == 0) {
+ u32 ctrl = readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+
+ dev_dbg(i2c_bus->dev, "timeout isr[%x], sts[%x]\n",
+ readl(i2c_bus->reg_base + AST2600_I2CM_ISR),
+ readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF));
+ writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+
+ if (i2c_bus->multi_master &&
+ (readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF) &
+ AST2600_I2CC_BUS_BUSY_STS))
+ ast2600_i2c_recover_bus(i2c_bus);
+
+ ret = -ETIMEDOUT;
+ } else {
+ ret = i2c_bus->cmd_err;
+ }
+
+ dev_dbg(i2c_bus->dev, "bus%d-m: %d end\n", i2c_bus->adap.nr, i2c_bus->cmd_err);
+
+controller_out:
+ if (i2c_bus->mode == DMA_MODE) {
+ if (i2c_bus->controller_dma_safe_buf) {
+ struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
+
+ if (msg->flags & I2C_M_RD)
+ dma_unmap_single(i2c_bus->dev, i2c_bus->controller_dma_addr,
+ msg->len, DMA_FROM_DEVICE);
+ else
+ dma_unmap_single(i2c_bus->dev, i2c_bus->controller_dma_addr,
+ msg->len, DMA_TO_DEVICE);
+ i2c_put_dma_safe_msg_buf(i2c_bus->controller_dma_safe_buf, msg, true);
+ i2c_bus->controller_dma_safe_buf = NULL;
+ }
+ }
+
+ return ret;
+}
+
+static void ast2600_i2c_init(struct ast2600_i2c_bus *i2c_bus)
+{
+ struct platform_device *pdev = to_platform_device(i2c_bus->dev);
+ u32 fun_ctrl = AST2600_I2CC_BUS_AUTO_RELEASE | AST2600_I2CC_MASTER_EN;
+
+ /* I2C Reset */
+ writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+
+ i2c_bus->multi_master = device_property_read_bool(&pdev->dev, "multi-master");
+ if (!i2c_bus->multi_master)
+ fun_ctrl |= AST2600_I2CC_MULTI_MASTER_DIS;
+
+ /* Enable Controller Mode */
+ writel(fun_ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ /* disable target address */
+ writel(0, i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
+
+ /* Set AC Timing */
+ writel(ast2600_select_i2c_clock(i2c_bus), i2c_bus->reg_base + AST2600_I2CC_AC_TIMING);
+
+ /* Clear Interrupt */
+ writel(GENMASK(27, 0), i2c_bus->reg_base + AST2600_I2CM_ISR);
+}
+
+static u32 ast2600_i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA;
+}
+
+static const struct i2c_algorithm i2c_ast2600_algorithm = {
+ .xfer = ast2600_i2c_controller_xfer,
+ .functionality = ast2600_i2c_functionality,
+};
+
+static int ast2600_i2c_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct ast2600_i2c_bus *i2c_bus;
+ const char *xfer_mode;
+ struct resource *res;
+ u32 global_ctrl;
+ int ret;
+
+ i2c_bus = devm_kzalloc(dev, sizeof(*i2c_bus), GFP_KERNEL);
+ if (!i2c_bus)
+ return -ENOMEM;
+
+ i2c_bus->reg_base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(i2c_bus->reg_base))
+ return PTR_ERR(i2c_bus->reg_base);
+
+ i2c_bus->rst = devm_reset_control_get_shared(dev, NULL);
+ if (IS_ERR(i2c_bus->rst))
+ return dev_err_probe(dev, PTR_ERR(i2c_bus->rst), "Missing reset ctrl\n");
+
+ i2c_bus->rst = devm_reset_control_get_shared_deasserted(dev, NULL);
+ if (IS_ERR(i2c_bus->rst))
+ return dev_err_probe(dev, PTR_ERR(i2c_bus->rst), "Missing reset ctrl\n");
+
+ i2c_bus->global_regs =
+ syscon_regmap_lookup_by_phandle(dev_of_node(dev), "aspeed,global-regs");
+ if (IS_ERR(i2c_bus->global_regs))
+ return PTR_ERR(i2c_bus->global_regs);
+
+ regmap_read(i2c_bus->global_regs, AST2600_I2CG_CTRL, &global_ctrl);
+ if ((global_ctrl & AST2600_GLOBAL_INIT) != AST2600_GLOBAL_INIT) {
+ regmap_write(i2c_bus->global_regs, AST2600_I2CG_CTRL, AST2600_GLOBAL_INIT);
+ regmap_write(i2c_bus->global_regs, AST2600_I2CG_CLK_DIV_CTRL, I2CCG_DIV_CTRL);
+ }
+
+ i2c_bus->dev = dev;
+ i2c_bus->mode = BUFF_MODE;
+ if (!device_property_read_string(dev, "aspeed,transfer-mode", &xfer_mode)) {
+ if (!strcmp(xfer_mode, "dma"))
+ i2c_bus->mode = DMA_MODE;
+ else if (!strcmp(xfer_mode, "byte"))
+ i2c_bus->mode = BYTE_MODE;
+ else
+ i2c_bus->mode = BUFF_MODE;
+ }
+
+ if (i2c_bus->mode == BUFF_MODE) {
+ i2c_bus->buf_base = devm_platform_get_and_ioremap_resource(pdev, 1, &res);
+ if (IS_ERR(i2c_bus->buf_base))
+ i2c_bus->mode = BYTE_MODE;
+ else
+ i2c_bus->buf_size = resource_size(res) / 2;
+ }
+
+ /*
+ * i2c timeout counter: use base clk4 1Mhz,
+ * per unit: 1/(1000/1024) = 1024us
+ */
+ ret = device_property_read_u32(dev, "i2c-scl-clk-low-timeout-us", &i2c_bus->timeout);
+ if (!ret)
+ i2c_bus->timeout /= 1024;
+
+ init_completion(&i2c_bus->cmd_complete);
+
+ i2c_bus->irq = platform_get_irq(pdev, 0);
+ if (i2c_bus->irq < 0)
+ return i2c_bus->irq;
+
+ platform_set_drvdata(pdev, i2c_bus);
+
+ i2c_bus->clk = devm_clk_get(i2c_bus->dev, NULL);
+ if (IS_ERR(i2c_bus->clk))
+ return dev_err_probe(i2c_bus->dev, PTR_ERR(i2c_bus->clk), "Can't get clock\n");
+
+ i2c_bus->apb_clk = clk_get_rate(i2c_bus->clk);
+
+ i2c_parse_fw_timings(i2c_bus->dev, &i2c_bus->timing_info, true);
+
+ /* Initialize the I2C adapter */
+ i2c_bus->adap.owner = THIS_MODULE;
+ i2c_bus->adap.algo = &i2c_ast2600_algorithm;
+ i2c_bus->adap.retries = 0;
+ i2c_bus->adap.dev.parent = i2c_bus->dev;
+ device_set_node(&i2c_bus->adap.dev, dev_fwnode(dev));
+ i2c_bus->adap.algo_data = i2c_bus;
+ strscpy(i2c_bus->adap.name, pdev->name);
+ i2c_set_adapdata(&i2c_bus->adap, i2c_bus);
+
+ ast2600_i2c_init(i2c_bus);
+
+ ret = devm_request_irq(dev, i2c_bus->irq, ast2600_i2c_bus_irq, 0,
+ dev_name(dev), i2c_bus);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Unable to request irq %d\n", i2c_bus->irq);
+
+ writel(AST2600_I2CM_PKT_DONE | AST2600_I2CM_BUS_RECOVER,
+ i2c_bus->reg_base + AST2600_I2CM_IER);
+
+ ret = devm_i2c_add_adapter(dev, &i2c_bus->adap);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static void ast2600_i2c_remove(struct platform_device *pdev)
+{
+ struct ast2600_i2c_bus *i2c_bus = platform_get_drvdata(pdev);
+
+ /* Disable everything. */
+ writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(0, i2c_bus->reg_base + AST2600_I2CM_IER);
+ reset_control_assert(i2c_bus->rst);
+}
+
+static const struct of_device_id ast2600_i2c_bus_of_table[] = {
+ {
+ .compatible = "aspeed,ast2600-i2c-bus",
+ },
+ {}
+};
+MODULE_DEVICE_TABLE(of, ast2600_i2c_bus_of_table);
+
+static struct platform_driver ast2600_i2c_bus_driver = {
+ .probe = ast2600_i2c_probe,
+ .remove = ast2600_i2c_remove,
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .of_match_table = ast2600_i2c_bus_of_table,
+ },
+};
+
+module_platform_driver(ast2600_i2c_bus_driver);
+
+MODULE_AUTHOR("Ryan Chen <ryan_chen@aspeedtech.com>");
+MODULE_DESCRIPTION("ASPEED AST2600 I2C Controller Driver");
+MODULE_LICENSE("GPL");
--
2.34.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v17 3/3] i2c: ast2600: Add target mode support
2025-08-14 8:41 [PATCH v17 0/3] Add ASPEED AST2600 I2C controller driver Ryan Chen
2025-08-14 8:41 ` [PATCH v17 1/3] dt-bindings: i2c: aspeed,i2c.yaml: add transfer-mode and global-regs properties and update example Ryan Chen
2025-08-14 8:41 ` [PATCH v17 2/3] i2c: ast2600: Add controller driver for new register layout Ryan Chen
@ 2025-08-14 8:41 ` Ryan Chen
2 siblings, 0 replies; 8+ messages in thread
From: Ryan Chen @ 2025-08-14 8:41 UTC (permalink / raw)
To: ryan_chen, benh, joel, andi.shyti, robh, krzk+dt, conor+dt,
andrew, p.zabel, andriy.shevchenko, naresh.solanki, linux-i2c,
openbmc, devicetree, linux-arm-kernel, linux-aspeed, linux-kernel
Add target mode support to the AST2600 I2C driver using
new register layout.
Target mode features implemented include:
- Add target interrupt handling
- Address match and response logic
- Separate Tx/Rx DMA address and length configuration
This complements the existing controller-mode support,
enabling dual-role capability.
Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
drivers/i2c/busses/i2c-ast2600.c | 560 +++++++++++++++++++++++++++++++
1 file changed, 560 insertions(+)
diff --git a/drivers/i2c/busses/i2c-ast2600.c b/drivers/i2c/busses/i2c-ast2600.c
index 15e600ff50ec..41e3a54b2a2b 100644
--- a/drivers/i2c/busses/i2c-ast2600.c
+++ b/drivers/i2c/busses/i2c-ast2600.c
@@ -81,6 +81,7 @@
#define AST2600_I2CC_THDDAT(x) (((x) & GENMASK(1, 0)) << 10)
#define AST2600_I2CC_TOUTBASECLK(x) (((x) & GENMASK(1, 0)) << 8)
#define AST2600_I2CC_TBASECLK(x) ((x) & GENMASK(3, 0))
+#define AST2600_I2CC_AC_TIMING_MASK GENMASK(23, 0)
/* 0x08 : I2CC Controller/Target Transmit/Receive Byte Buffer Register */
#define AST2600_I2CC_STS_AND_BUFF 0x08
@@ -271,6 +272,13 @@ struct ast2600_i2c_bus {
/* Buffer mode */
void __iomem *buf_base;
struct i2c_smbus_alert_setup alert_data;
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ /* target structure */
+ int target_operate;
+ unsigned char *target_dma_buf;
+ dma_addr_t target_dma_addr;
+ struct i2c_client *target;
+#endif
};
static u32 ast2600_select_i2c_clock(struct ast2600_i2c_bus *i2c_bus)
@@ -361,6 +369,423 @@ static int ast2600_i2c_recover_bus(struct ast2600_i2c_bus *i2c_bus)
return ret;
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static void ast2600_i2c_target_packet_dma_irq(struct ast2600_i2c_bus *i2c_bus, u32 sts)
+{
+ int target_rx_len = 0;
+ u32 cmd = 0;
+ u8 value;
+ int i;
+
+ sts &= ~(AST2600_I2CS_SLAVE_PENDING);
+ /* Handle i2c target timeout condition */
+ if (AST2600_I2CS_INACTIVE_TO & sts) {
+ cmd = TARGET_TRIGGER_CMD;
+ cmd |= AST2600_I2CS_RX_DMA_EN;
+ writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_TARGET_MSG_BUF_SIZE),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_ISR);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ return;
+ }
+
+ sts &= ~(AST2600_I2CS_PKT_DONE | AST2600_I2CS_PKT_ERROR);
+
+ switch (sts) {
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_RX_DMA:
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_WAIT_RX_DMA:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+ target_rx_len = AST2600_I2C_GET_RX_DMA_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CS_DMA_LEN_STS));
+ for (i = 0; i < target_rx_len; i++) {
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED,
+ &i2c_bus->target_dma_buf[i]);
+ }
+ writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_TARGET_MSG_BUF_SIZE),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_RX_DMA_EN;
+ break;
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_STOP:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_TARGET_MSG_BUF_SIZE),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_RX_DMA_EN;
+ break;
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE_NAK |
+ AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_WAIT_RX_DMA |
+ AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ case AST2600_I2CS_RX_DONE_NAK | AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ case AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_STOP:
+ case AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ case AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_RX_DMA:
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ if (sts & AST2600_I2CS_SLAVE_MATCH)
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+
+ target_rx_len = AST2600_I2C_GET_RX_DMA_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CS_DMA_LEN_STS));
+ for (i = 0; i < target_rx_len; i++) {
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED,
+ &i2c_bus->target_dma_buf[i]);
+ }
+ writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_TARGET_MSG_BUF_SIZE),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ if (sts & AST2600_I2CS_STOP)
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_RX_DMA_EN;
+ break;
+
+ /* it is Mw data Mr coming -> it need send tx */
+ case AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_TX_DMA:
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_TX_DMA:
+ /* it should be repeat start read */
+ if (sts & AST2600_I2CS_SLAVE_MATCH)
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+
+ target_rx_len = AST2600_I2C_GET_RX_DMA_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CS_DMA_LEN_STS));
+ for (i = 0; i < target_rx_len; i++) {
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED,
+ &i2c_bus->target_dma_buf[i]);
+ }
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_REQUESTED,
+ &i2c_bus->target_dma_buf[0]);
+ writel(0, i2c_bus->reg_base + AST2600_I2CS_DMA_LEN_STS);
+ writel(AST2600_I2CS_SET_TX_DMA_LEN(1),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_TX_DMA_EN;
+ break;
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_WAIT_TX_DMA:
+ /* First Start read */
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_REQUESTED,
+ &i2c_bus->target_dma_buf[0]);
+ writel(AST2600_I2CS_SET_TX_DMA_LEN(1),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_TX_DMA_EN;
+ break;
+ case AST2600_I2CS_WAIT_TX_DMA:
+ /* it should be next start read */
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_PROCESSED,
+ &i2c_bus->target_dma_buf[0]);
+ writel(0, i2c_bus->reg_base + AST2600_I2CS_DMA_LEN_STS);
+ writel(AST2600_I2CS_SET_TX_DMA_LEN(1),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_TX_DMA_EN;
+ break;
+ case AST2600_I2CS_TX_NAK | AST2600_I2CS_STOP:
+ /* it just tx complete */
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ writel(0, i2c_bus->reg_base + AST2600_I2CS_DMA_LEN_STS);
+ writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_TARGET_MSG_BUF_SIZE),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_RX_DMA_EN;
+ break;
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
+ cmd = 0;
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+ break;
+ case AST2600_I2CS_STOP:
+ cmd = 0;
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ break;
+ default:
+ dev_dbg(i2c_bus->dev, "unhandled target isr case %x, sts %x\n", sts,
+ readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF));
+ break;
+ }
+
+ if (cmd)
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_ISR);
+ readl(i2c_bus->reg_base + AST2600_I2CS_ISR);
+}
+
+static void ast2600_i2c_target_packet_buff_irq(struct ast2600_i2c_bus *i2c_bus, u32 sts)
+{
+ int target_rx_len = 0;
+ u32 cmd = 0;
+ u8 value;
+ int i;
+
+ /* due to controller target is common buffer, need force the master stop not issue */
+ if (readl(i2c_bus->reg_base + AST2600_I2CM_CMD_STS) & GENMASK(15, 0)) {
+ writel(0, i2c_bus->reg_base + AST2600_I2CM_CMD_STS);
+ i2c_bus->cmd_err = -EBUSY;
+ writel(0, i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ complete(&i2c_bus->cmd_complete);
+ }
+
+ /* Handle i2c target timeout condition */
+ if (AST2600_I2CS_INACTIVE_TO & sts) {
+ /* Reset timeout counter */
+ u32 ac_timing = readl(i2c_bus->reg_base + AST2600_I2CC_AC_TIMING) &
+ AST2600_I2CC_AC_TIMING_MASK;
+
+ writel(ac_timing, i2c_bus->reg_base + AST2600_I2CC_AC_TIMING);
+ ac_timing |= AST2600_I2CC_TTIMEOUT(i2c_bus->timeout);
+ writel(ac_timing, i2c_bus->reg_base + AST2600_I2CC_AC_TIMING);
+ writel(TARGET_TRIGGER_CMD, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_ISR);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ i2c_bus->target_operate = 0;
+ return;
+ }
+
+ sts &= ~(AST2600_I2CS_PKT_DONE | AST2600_I2CS_PKT_ERROR);
+
+ if (sts & AST2600_I2CS_SLAVE_MATCH)
+ i2c_bus->target_operate = 1;
+
+ switch (sts) {
+ case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_WAIT_RX_DMA |
+ AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ case AST2600_I2CS_SLAVE_PENDING |
+ AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ case AST2600_I2CS_SLAVE_PENDING |
+ AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_STOP:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ fallthrough;
+ case AST2600_I2CS_SLAVE_PENDING |
+ AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
+ case AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
+ case AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_SLAVE_MATCH:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+ cmd = TARGET_TRIGGER_CMD;
+ if (sts & AST2600_I2CS_RX_DONE) {
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ }
+ if (readl(i2c_bus->reg_base + AST2600_I2CS_CMD_STS) & AST2600_I2CS_RX_BUFF_EN)
+ cmd = 0;
+ else
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_RX_BUFF_EN;
+
+ writel(AST2600_I2CC_SET_RX_BUF_LEN(i2c_bus->buf_size),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ break;
+ case AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_RX_DONE:
+ cmd = TARGET_TRIGGER_CMD;
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ cmd |= AST2600_I2CS_RX_BUFF_EN;
+ writel(AST2600_I2CC_SET_RX_BUF_LEN(i2c_bus->buf_size),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ break;
+ case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_WAIT_RX_DMA |
+ AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ cmd = TARGET_TRIGGER_CMD;
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ cmd |= AST2600_I2CS_RX_BUFF_EN;
+ writel(AST2600_I2CC_SET_RX_BUF_LEN(i2c_bus->buf_size),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ break;
+ case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ cmd = TARGET_TRIGGER_CMD;
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ /* workaround for avoid next start with len != 0 */
+ writel(BIT(0), i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ break;
+ case AST2600_I2CS_RX_DONE | AST2600_I2CS_STOP:
+ cmd = TARGET_TRIGGER_CMD;
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ /* workaround for avoid next start with len != 0 */
+ writel(BIT(0), i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ break;
+ case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_RX_DONE |
+ AST2600_I2CS_WAIT_TX_DMA | AST2600_I2CS_STOP:
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_REQUESTED, &value);
+ writeb(value, i2c_bus->buf_base);
+ break;
+ case AST2600_I2CS_WAIT_TX_DMA | AST2600_I2CS_SLAVE_MATCH:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_REQUESTED, &value);
+ writeb(value, i2c_bus->buf_base);
+ writel(AST2600_I2CC_SET_TX_BUF_LEN(1),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_TX_BUFF_EN;
+ break;
+ case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_STOP |
+ AST2600_I2CS_TX_NAK | AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
+ case AST2600_I2CS_SLAVE_PENDING | AST2600_I2CS_WAIT_RX_DMA | AST2600_I2CS_STOP |
+ AST2600_I2CS_TX_NAK | AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ writel(AST2600_I2CC_SET_RX_BUF_LEN(i2c_bus->buf_size),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_RX_BUFF_EN;
+ break;
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_WAIT_TX_DMA | AST2600_I2CS_RX_DONE:
+ case AST2600_I2CS_WAIT_TX_DMA | AST2600_I2CS_RX_DONE:
+ case AST2600_I2CS_WAIT_TX_DMA:
+ if (sts & AST2600_I2CS_SLAVE_MATCH)
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+
+ if (sts & AST2600_I2CS_RX_DONE) {
+ target_rx_len = AST2600_I2CC_GET_RX_BUF_LEN(readl(i2c_bus->reg_base +
+ AST2600_I2CC_BUFF_CTRL));
+ for (i = 0; i < target_rx_len; i++) {
+ value = readb(i2c_bus->buf_base + 0x10 + i);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &value);
+ }
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_REQUESTED, &value);
+ } else {
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_PROCESSED, &value);
+ }
+ writeb(value, i2c_bus->buf_base);
+ writel(AST2600_I2CC_SET_TX_BUF_LEN(1),
+ i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_TX_BUFF_EN;
+ break;
+ /* workaround : trigger the cmd twice to fix next state keep 1000000 */
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+ cmd = TARGET_TRIGGER_CMD | AST2600_I2CS_RX_BUFF_EN;
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ break;
+
+ case AST2600_I2CS_TX_NAK | AST2600_I2CS_STOP:
+ case AST2600_I2CS_STOP:
+ cmd = TARGET_TRIGGER_CMD;
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ break;
+ default:
+ dev_dbg(i2c_bus->dev, "unhandled target isr case %x, sts %x\n", sts,
+ readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF));
+ break;
+ }
+
+ if (cmd)
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_ISR);
+ readl(i2c_bus->reg_base + AST2600_I2CS_ISR);
+
+ if ((sts & AST2600_I2CS_STOP) && !(sts & AST2600_I2CS_SLAVE_PENDING))
+ i2c_bus->target_operate = 0;
+}
+
+static void ast2600_i2c_target_byte_irq(struct ast2600_i2c_bus *i2c_bus, u32 sts)
+{
+ u32 i2c_buff = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
+ u32 cmd = AST2600_I2CS_ACTIVE_ALL;
+ u8 byte_data;
+ u8 value;
+
+ switch (sts) {
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_RX_DMA:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_REQUESTED, &value);
+ /* first address match is address */
+ byte_data = AST2600_I2CC_GET_RX_BUFF(i2c_buff);
+ break;
+ case AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_RX_DMA:
+ byte_data = AST2600_I2CC_GET_RX_BUFF(i2c_buff);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_WRITE_RECEIVED, &byte_data);
+ break;
+ case AST2600_I2CS_SLAVE_MATCH | AST2600_I2CS_RX_DONE | AST2600_I2CS_WAIT_TX_DMA:
+ cmd |= AST2600_I2CS_TX_CMD;
+ byte_data = AST2600_I2CC_GET_RX_BUFF(i2c_buff);
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_REQUESTED, &byte_data);
+ writel(byte_data, i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
+ break;
+ case AST2600_I2CS_TX_ACK | AST2600_I2CS_WAIT_TX_DMA:
+ cmd |= AST2600_I2CS_TX_CMD;
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_READ_PROCESSED, &byte_data);
+ writel(byte_data, i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF);
+ break;
+ case AST2600_I2CS_STOP:
+ case AST2600_I2CS_STOP | AST2600_I2CS_TX_NAK:
+ i2c_slave_event(i2c_bus->target, I2C_SLAVE_STOP, &value);
+ break;
+ default:
+ dev_dbg(i2c_bus->dev, "unhandled pkt isr %x\n", sts);
+ break;
+ }
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ writel(sts, i2c_bus->reg_base + AST2600_I2CS_ISR);
+ readl(i2c_bus->reg_base + AST2600_I2CS_ISR);
+}
+
+static int ast2600_i2c_target_irq(struct ast2600_i2c_bus *i2c_bus)
+{
+ u32 ier = readl(i2c_bus->reg_base + AST2600_I2CS_IER);
+ u32 isr = readl(i2c_bus->reg_base + AST2600_I2CS_ISR);
+
+ if (!(isr & ier))
+ return 0;
+
+ /*
+ * Target interrupt coming after Master package done
+ * So need handle master first.
+ */
+ if (readl(i2c_bus->reg_base + AST2600_I2CM_ISR) & AST2600_I2CM_PKT_DONE)
+ return 0;
+
+ isr &= ~(AST2600_I2CS_ADDR_INDICATE_MASK);
+
+ if (AST2600_I2CS_ADDR1_NAK & isr)
+ isr &= ~AST2600_I2CS_ADDR1_NAK;
+
+ if (AST2600_I2CS_ADDR2_NAK & isr)
+ isr &= ~AST2600_I2CS_ADDR2_NAK;
+
+ if (AST2600_I2CS_ADDR3_NAK & isr)
+ isr &= ~AST2600_I2CS_ADDR3_NAK;
+
+ if (AST2600_I2CS_ADDR_MASK & isr)
+ isr &= ~AST2600_I2CS_ADDR_MASK;
+
+ if (AST2600_I2CS_PKT_DONE & isr) {
+ if (i2c_bus->mode == DMA_MODE)
+ ast2600_i2c_target_packet_dma_irq(i2c_bus, isr);
+ else
+ ast2600_i2c_target_packet_buff_irq(i2c_bus, isr);
+ } else {
+ ast2600_i2c_target_byte_irq(i2c_bus, isr);
+ }
+
+ return 1;
+}
+#endif
+
static int ast2600_i2c_setup_dma_tx(u32 cmd, struct ast2600_i2c_bus *i2c_bus)
{
struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index];
@@ -690,6 +1115,20 @@ static void ast2600_i2c_controller_package_irq(struct ast2600_i2c_bus *i2c_bus,
}
break;
case AST2600_I2CM_RX_DONE:
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ /*
+ * Workaround for controller/target package mode enable rx done stuck issue
+ * When master go for first read (RX_DONE), target mode will also effect
+ * Then controller will send nack, not operate anymore.
+ */
+ if (readl(i2c_bus->reg_base + AST2600_I2CS_CMD_STS) & AST2600_I2CS_PKT_MODE_EN) {
+ u32 target_cmd = readl(i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+
+ writel(0, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ writel(target_cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ }
+ fallthrough;
+#endif
case AST2600_I2CM_RX_DONE | AST2600_I2CM_NORMAL_STOP:
/* do next rx */
if (i2c_bus->mode == DMA_MODE) {
@@ -799,6 +1238,12 @@ static irqreturn_t ast2600_i2c_bus_irq(int irq, void *dev_id)
{
struct ast2600_i2c_bus *i2c_bus = dev_id;
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ if (readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL) & AST2600_I2CC_SLAVE_EN) {
+ if (ast2600_i2c_target_irq(i2c_bus))
+ return IRQ_HANDLED;
+ }
+#endif
return IRQ_RETVAL(ast2600_i2c_controller_irq(i2c_bus));
}
@@ -815,12 +1260,30 @@ static int ast2600_i2c_controller_xfer(struct i2c_adapter *adap, struct i2c_msg
return ret;
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ if (i2c_bus->mode == BUFF_MODE) {
+ if (i2c_bus->target_operate)
+ return -EBUSY;
+ /* disable target isr */
+ writel(0, i2c_bus->reg_base + AST2600_I2CS_IER);
+ if (readl(i2c_bus->reg_base + AST2600_I2CS_ISR) || i2c_bus->target_operate) {
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_IER);
+ return -EBUSY;
+ }
+ }
+#endif
+
i2c_bus->cmd_err = 0;
i2c_bus->msgs = msgs;
i2c_bus->msgs_index = 0;
i2c_bus->msgs_count = num;
reinit_completion(&i2c_bus->cmd_complete);
ret = ast2600_i2c_do_start(i2c_bus);
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ /* avoid race condication target is wait and master wait 1st target operate */
+ if (i2c_bus->mode == BUFF_MODE)
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_IER);
+#endif
if (ret)
goto controller_out;
timeout = wait_for_completion_timeout(&i2c_bus->cmd_complete, i2c_bus->adap.timeout);
@@ -837,7 +1300,26 @@ static int ast2600_i2c_controller_xfer(struct i2c_adapter *adap, struct i2c_msg
(readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF) &
AST2600_I2CC_BUS_BUSY_STS))
ast2600_i2c_recover_bus(i2c_bus);
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ if (ctrl & AST2600_I2CC_SLAVE_EN) {
+ u32 cmd = TARGET_TRIGGER_CMD;
+ if (i2c_bus->mode == DMA_MODE) {
+ cmd |= AST2600_I2CS_RX_DMA_EN;
+ writel(i2c_bus->target_dma_addr,
+ i2c_bus->reg_base + AST2600_I2CS_RX_DMA);
+ writel(i2c_bus->target_dma_addr,
+ i2c_bus->reg_base + AST2600_I2CS_TX_DMA);
+ writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_TARGET_MSG_BUF_SIZE),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ } else if (i2c_bus->mode == BUFF_MODE) {
+ cmd = TARGET_TRIGGER_CMD;
+ } else {
+ cmd &= ~AST2600_I2CS_PKT_MODE_EN;
+ }
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ }
+#endif
ret = -ETIMEDOUT;
} else {
ret = i2c_bus->cmd_err;
@@ -886,7 +1368,78 @@ static void ast2600_i2c_init(struct ast2600_i2c_bus *i2c_bus)
/* Clear Interrupt */
writel(GENMASK(27, 0), i2c_bus->reg_base + AST2600_I2CM_ISR);
+
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ /* for memory buffer initial */
+ if (i2c_bus->mode == DMA_MODE) {
+ i2c_bus->target_dma_buf =
+ dmam_alloc_coherent(i2c_bus->dev, I2C_TARGET_MSG_BUF_SIZE,
+ &i2c_bus->target_dma_addr, GFP_KERNEL);
+ if (!i2c_bus->target_dma_buf)
+ return;
+ }
+
+ writel(GENMASK(27, 0), i2c_bus->reg_base + AST2600_I2CS_ISR);
+
+ if (i2c_bus->mode == BYTE_MODE)
+ writel(GENMASK(15, 0), i2c_bus->reg_base + AST2600_I2CS_IER);
+ else
+ writel(AST2600_I2CS_PKT_DONE, i2c_bus->reg_base + AST2600_I2CS_IER);
+#endif
+}
+
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static int ast2600_i2c_reg_target(struct i2c_client *client)
+{
+ struct ast2600_i2c_bus *i2c_bus = i2c_get_adapdata(client->adapter);
+ u32 cmd = TARGET_TRIGGER_CMD;
+
+ if (i2c_bus->target)
+ return -EINVAL;
+
+ dev_dbg(i2c_bus->dev, "target addr %x\n", client->addr);
+
+ writel(0, i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
+ writel(AST2600_I2CC_SLAVE_EN | readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL),
+ i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+
+ /* trigger rx buffer */
+ if (i2c_bus->mode == DMA_MODE) {
+ cmd |= AST2600_I2CS_RX_DMA_EN;
+ writel(i2c_bus->target_dma_addr, i2c_bus->reg_base + AST2600_I2CS_RX_DMA);
+ writel(i2c_bus->target_dma_addr, i2c_bus->reg_base + AST2600_I2CS_TX_DMA);
+ writel(AST2600_I2CS_SET_RX_DMA_LEN(I2C_TARGET_MSG_BUF_SIZE),
+ i2c_bus->reg_base + AST2600_I2CS_DMA_LEN);
+ } else if (i2c_bus->mode == BUFF_MODE) {
+ cmd = TARGET_TRIGGER_CMD;
+ } else {
+ cmd &= ~AST2600_I2CS_PKT_MODE_EN;
+ }
+
+ writel(cmd, i2c_bus->reg_base + AST2600_I2CS_CMD_STS);
+ i2c_bus->target = client;
+ /* Set target addr. */
+ writel(client->addr | AST2600_I2CS_ADDR1_ENABLE,
+ i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
+
+ return 0;
+}
+
+static int ast2600_i2c_unreg_target(struct i2c_client *client)
+{
+ struct ast2600_i2c_bus *i2c_bus = i2c_get_adapdata(client->adapter);
+
+ /* Turn off target mode. */
+ writel(~AST2600_I2CC_SLAVE_EN & readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL),
+ i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
+ writel(readl(i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL) & ~AST2600_I2CS_ADDR1_MASK,
+ i2c_bus->reg_base + AST2600_I2CS_ADDR_CTRL);
+
+ i2c_bus->target = NULL;
+
+ return 0;
}
+#endif
static u32 ast2600_i2c_functionality(struct i2c_adapter *adap)
{
@@ -896,6 +1449,10 @@ static u32 ast2600_i2c_functionality(struct i2c_adapter *adap)
static const struct i2c_algorithm i2c_ast2600_algorithm = {
.xfer = ast2600_i2c_controller_xfer,
.functionality = ast2600_i2c_functionality,
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ .reg_target = ast2600_i2c_reg_target,
+ .unreg_target = ast2600_i2c_unreg_target,
+#endif
};
static int ast2600_i2c_probe(struct platform_device *pdev)
@@ -934,6 +1491,9 @@ static int ast2600_i2c_probe(struct platform_device *pdev)
regmap_write(i2c_bus->global_regs, AST2600_I2CG_CLK_DIV_CTRL, I2CCG_DIV_CTRL);
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ i2c_bus->target_operate = 0;
+#endif
i2c_bus->dev = dev;
i2c_bus->mode = BUFF_MODE;
if (!device_property_read_string(dev, "aspeed,transfer-mode", &xfer_mode)) {
--
2.34.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v17 2/3] i2c: ast2600: Add controller driver for new register layout
2025-08-14 8:41 ` [PATCH v17 2/3] i2c: ast2600: Add controller driver for new register layout Ryan Chen
@ 2025-08-14 10:42 ` Philipp Zabel
2025-08-15 5:36 ` Ryan Chen
0 siblings, 1 reply; 8+ messages in thread
From: Philipp Zabel @ 2025-08-14 10:42 UTC (permalink / raw)
To: Ryan Chen, benh, joel, andi.shyti, robh, krzk+dt, conor+dt,
andrew, andriy.shevchenko, naresh.solanki, linux-i2c, openbmc,
devicetree, linux-arm-kernel, linux-aspeed, linux-kernel
On Do, 2025-08-14 at 16:41 +0800, Ryan Chen wrote:
> Add i2c-ast2600 new register mode driver to support AST2600
> i2c new register mode. This i2c-ast2600 new driver and the
> legacy i2c-aspeed driver both match the same compatible string
> "aspeed,ast2600-i2c-bus" because they target the same I2C
> controller IP on AST2600. However, AST2600 SoCs may configure
> the controller instances to operate either in the legacy
> register layout or the new layout (via global register).
> The new register mode support following.
>
> - Add new clock divider option for more flexible and accurate
> clock rate generation
> - Add tCKHighMin timing to guarantee SCL high pulse width.
> - Add support dual pool buffer mode, split 32 bytes pool buffer
> of each device into 2 x 16 bytes for Tx and Rx individually.
> - Increase DMA buffer size to 4096 bytes and support byte alignment.
> - Re-define the base address of BUS1 ~ BUS16 and Pool buffer.
> - Re-define registers for separating controller and target
> mode control.
> - Support 4 individual DMA buffers for controller Tx and Rx,
> target Tx and Rx.
>
> And following is new register set for package transfer sequence.
> - New Master operation mode:
> S -> Aw -> P
> S -> Aw -> TxD -> P
> S -> Ar -> RxD -> P
> S -> Aw -> TxD -> Sr -> Ar -> RxD -> P
> - Bus SDA lock auto-release capability for new controller DMA
> command mode.
> - Bus auto timeout for new controller/target DMA mode.
>
> Since the register layout is selected via a global register at
> runtime and both drivers bind to the same compatible string,
> this patch defines the driver selection at build-time using
> Kconfig, ensuring that only one driver is compiled into the
> kernel. This approach avoids ambiguity and ensures consistent
> behavior for each platform configuration.
>
> The following is two versus register layout.
> Old register mode:
> {I2CD00}: Function Control Register
> {I2CD04}: Clock and AC Timing Control Register
> {I2CD08}: Clock and AC Timing Control Register
> {I2CD0C}: Interrupt Control Register
> {I2CD10}: Interrupt Status Register
> {I2CD14}: Command/Status Register
> {I2CD18}: Slave Device Address Register
> {I2CD1C}: Pool Buffer Control Register
> {I2CD20}: Transmit/Receive Byte Buffer Register
> {I2CD24}: DMA Mode Buffer Address Register
> {I2CD28}: DMA Transfer Length Register
> {I2CD2C}: Original DMA Mode Buffer Address Setting
> {I2CD30}: Original DMA Transfer Length Setting and Final Status
>
> New Register mode
> {I2CC00}: Master/Slave Function Control Register
> {I2CC04}: Master/Slave Clock and AC Timing Control Register
> {I2CC08}: Master/Slave Transmit/Receive Byte Buffer Register
> {I2CC0C}: Master/Slave Pool Buffer Control Register
> {I2CM10}: Master Interrupt Control Register
> {I2CM14}: Master Interrupt Status Register
> {I2CM18}: Master Command/Status Register
> {I2CM1C}: Master DMA Buffer Length Register
> {I2CS20}: Slave~ Interrupt Control Register
> {I2CS24}: Slave~ Interrupt Status Register
> {I2CS28}: Slave~ Command/Status Register
> {I2CS2C}: Slave~ DMA Buffer Length Register
> {I2CM30}: Master DMA Mode Tx Buffer Base Address
> {I2CM34}: Master DMA Mode Rx Buffer Base Address
> {I2CS38}: Slave~ DMA Mode Tx Buffer Base Address
> {I2CS3C}: Slave~ DMA Mode Rx Buffer Base Address
> {I2CS40}: Slave Device Address Register
> {I2CM48}: Master DMA Length Status Register
> {I2CS4C}: Slave DMA Length Status Register
> {I2CC50}: Current DMA Operating Address Status
> {I2CC54}: Current DMA Operating Length Status
>
> Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
> ---
> drivers/i2c/busses/Kconfig | 23 +-
> drivers/i2c/busses/Makefile | 1 +
> drivers/i2c/busses/i2c-ast2600.c | 1038 ++++++++++++++++++++++++++++++
> 3 files changed, 1054 insertions(+), 8 deletions(-)
> create mode 100644 drivers/i2c/busses/i2c-ast2600.c
>
[...]
> diff --git a/drivers/i2c/busses/i2c-ast2600.c b/drivers/i2c/busses/i2c-ast2600.c
> new file mode 100644
> index 000000000000..15e600ff50ec
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-ast2600.c
> @@ -0,0 +1,1038 @@
[...]
> +static int ast2600_i2c_probe(struct platform_device *pdev)
> +{
>
[...]
> + i2c_bus->rst = devm_reset_control_get_shared(dev, NULL);
> + if (IS_ERR(i2c_bus->rst))
> + return dev_err_probe(dev, PTR_ERR(i2c_bus->rst), "Missing reset ctrl\n");
What ...
> + i2c_bus->rst = devm_reset_control_get_shared_deasserted(dev, NULL);
> + if (IS_ERR(i2c_bus->rst))
> + return dev_err_probe(dev, PTR_ERR(i2c_bus->rst), "Missing reset ctrl\n");
... is this?
Choose one. If you use 1), call reset_control_deassert() somewhere. If
you use 2), remove reset_control_assert() below.
[...]
> +static void ast2600_i2c_remove(struct platform_device *pdev)
> +{
> + struct ast2600_i2c_bus *i2c_bus = platform_get_drvdata(pdev);
> +
> + /* Disable everything. */
> + writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> + writel(0, i2c_bus->reg_base + AST2600_I2CM_IER);
> + reset_control_assert(i2c_bus->rst);
Drop if using devm_reset_control_get_shared_deasserted()
regards
Philipp
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v17 1/3] dt-bindings: i2c: aspeed,i2c.yaml: add transfer-mode and global-regs properties and update example
2025-08-14 8:41 ` [PATCH v17 1/3] dt-bindings: i2c: aspeed,i2c.yaml: add transfer-mode and global-regs properties and update example Ryan Chen
@ 2025-08-14 22:30 ` Rob Herring
2025-08-15 7:06 ` Ryan Chen
0 siblings, 1 reply; 8+ messages in thread
From: Rob Herring @ 2025-08-14 22:30 UTC (permalink / raw)
To: Ryan Chen
Cc: benh, joel, andi.shyti, krzk+dt, conor+dt, andrew, p.zabel,
andriy.shevchenko, naresh.solanki, linux-i2c, openbmc, devicetree,
linux-arm-kernel, linux-aspeed, linux-kernel
On Thu, Aug 14, 2025 at 04:41:54PM +0800, Ryan Chen wrote:
> - Add property "aspeed,global-regs" to get phandle set global
> register, for register mode selection and clock divider control.
> - Add an optional property "aspeed,transfer-mode" to
> allow device tree to specify the desired transfer method used
> by each I2C controller instance.
> - Update example to demonstrate usage of 'aspeed,global-regs' and
> 'aspeed,transfer-mode' for AST2600 I2C controller.
All of this is evident reading the patch. Explain here why you need this
change.
>
> Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
> ---
> .../devicetree/bindings/i2c/aspeed,i2c.yaml | 39 +++++++++++++++++++
> 1 file changed, 39 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml b/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
> index 5b9bd2feda3b..2a9f7d1d2ea1 100644
> --- a/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
> +++ b/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
> @@ -44,6 +44,34 @@ properties:
> description: frequency of the bus clock in Hz defaults to 100 kHz when not
> specified
>
> + aspeed,transfer-mode:
> + description: |
> + ASPEED ast2600 platform equipped with 16 I2C controllers each i2c controller
> + have 1 byte transfer buffer(byte mode), 32 bytes buffer(buffer mode), and
> + share a DMA engine.
> + Select I2C transfer mode for this controller. Supported values are:
> + - "byte": Use 1 byte for i2c transmit (1-byte buffer).
> + - "buffer": Use buffer (32-byte buffer) for i2c transmit. (default)
> + Better performance then byte mode.
If no 'aspeed,transfer-mode' property defaults to buffer mode, you never
need 'aspeed,transfer-mode = "buffer"'.
When would you ever use "byte" mode? Sometimes you want worse
performance? That makes no sense.
I feel like we already discussed this, but I'm not going to dig thru 17
versions to see.
> + - "dma": Each controller DMA mode is shared DMA engine. The AST2600 SoC
> + provides a single DMA engine shared for 16 I2C controllers,
> + so only a limited number of controllers can use DMA simultaneously.
> + Therefore, the DTS must explicitly assign which controllers are
> + configured to use DMA.
> + Only one mode can be selected per controller.
The only thing that really makes sense is dma, and you need 1 boolean
property for that. IOW, what you had on v10 which we gave reviewed-by 2+
years ago.
Do you have any actual test results or usecase that show DMA is useful
here? Typical I2C xfers are not streaming large amounts of data to
justify the setup costs of DMA. It wouldn't surprise me if DMA was
actually slower.
> + On AST2600, each controller supports all three modes.
> + If not specified, buffer mode is used by default.
> + enum:
> + - byte
> + - buffer
> + - dma
> +
> + aspeed,global-regs:
> + $ref: /schemas/types.yaml#/definitions/phandle
> + description: |
Don't need '|'. Read the documentation about when it is needed or not
needed.
> + The phandle of i2c global register node, For control the i2c register
> + define selection, clock divider mode selection and clock divider control.
> +
> required:
> - reg
> - compatible
> @@ -66,3 +94,14 @@ examples:
> interrupts = <0>;
> interrupt-parent = <&i2c_ic>;
> };
> + - |
> + #include <dt-bindings/interrupt-controller/arm-gic.h>
> + i2c1: i2c@80 {
> + compatible = "aspeed,ast2600-i2c-bus";
> + reg = <0x80 0x80>, <0xc00 0x20>;
> + aspeed,global-regs = <&i2c_global>;
> + clocks = <&syscon ASPEED_CLK_APB>;
> + resets = <&syscon ASPEED_RESET_I2C>;
> + interrupts = <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>;
> + aspeed,transfer-mode = "buffer";
> + };
> --
> 2.34.1
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* RE: [PATCH v17 2/3] i2c: ast2600: Add controller driver for new register layout
2025-08-14 10:42 ` Philipp Zabel
@ 2025-08-15 5:36 ` Ryan Chen
0 siblings, 0 replies; 8+ messages in thread
From: Ryan Chen @ 2025-08-15 5:36 UTC (permalink / raw)
To: Philipp Zabel, benh@kernel.crashing.org, joel@jms.id.au,
andi.shyti@kernel.org, robh@kernel.org, krzk+dt@kernel.org,
conor+dt@kernel.org, andrew@codeconstruct.com.au,
andriy.shevchenko@linux.intel.com, naresh.solanki@9elements.com,
linux-i2c@vger.kernel.org, openbmc@lists.ozlabs.org,
devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org
> Subject: Re: [PATCH v17 2/3] i2c: ast2600: Add controller driver for new
> register layout
>
> On Do, 2025-08-14 at 16:41 +0800, Ryan Chen wrote:
> > Add i2c-ast2600 new register mode driver to support AST2600 i2c new
> > register mode. This i2c-ast2600 new driver and the legacy i2c-aspeed
> > driver both match the same compatible string "aspeed,ast2600-i2c-bus"
> > because they target the same I2C controller IP on AST2600. However,
> > AST2600 SoCs may configure the controller instances to operate either
> > in the legacy register layout or the new layout (via global register).
> > The new register mode support following.
> >
> > - Add new clock divider option for more flexible and accurate clock
> > rate generation
> > - Add tCKHighMin timing to guarantee SCL high pulse width.
> > - Add support dual pool buffer mode, split 32 bytes pool buffer of
> > each device into 2 x 16 bytes for Tx and Rx individually.
> > - Increase DMA buffer size to 4096 bytes and support byte alignment.
> > - Re-define the base address of BUS1 ~ BUS16 and Pool buffer.
> > - Re-define registers for separating controller and target mode
> > control.
> > - Support 4 individual DMA buffers for controller Tx and Rx, target
> > Tx and Rx.
> >
> > And following is new register set for package transfer sequence.
> > - New Master operation mode:
> > S -> Aw -> P
> > S -> Aw -> TxD -> P
> > S -> Ar -> RxD -> P
> > S -> Aw -> TxD -> Sr -> Ar -> RxD -> P
> > - Bus SDA lock auto-release capability for new controller DMA command
> > mode.
> > - Bus auto timeout for new controller/target DMA mode.
> >
> > Since the register layout is selected via a global register at runtime
> > and both drivers bind to the same compatible string, this patch
> > defines the driver selection at build-time using Kconfig, ensuring
> > that only one driver is compiled into the kernel. This approach avoids
> > ambiguity and ensures consistent behavior for each platform
> > configuration.
> >
> > The following is two versus register layout.
> > Old register mode:
> > {I2CD00}: Function Control Register
> > {I2CD04}: Clock and AC Timing Control Register
> > {I2CD08}: Clock and AC Timing Control Register
> > {I2CD0C}: Interrupt Control Register
> > {I2CD10}: Interrupt Status Register
> > {I2CD14}: Command/Status Register
> > {I2CD18}: Slave Device Address Register
> > {I2CD1C}: Pool Buffer Control Register
> > {I2CD20}: Transmit/Receive Byte Buffer Register
> > {I2CD24}: DMA Mode Buffer Address Register
> > {I2CD28}: DMA Transfer Length Register
> > {I2CD2C}: Original DMA Mode Buffer Address Setting
> > {I2CD30}: Original DMA Transfer Length Setting and Final Status
> >
> > New Register mode
> > {I2CC00}: Master/Slave Function Control Register
> > {I2CC04}: Master/Slave Clock and AC Timing Control Register
> > {I2CC08}: Master/Slave Transmit/Receive Byte Buffer Register
> > {I2CC0C}: Master/Slave Pool Buffer Control Register
> > {I2CM10}: Master Interrupt Control Register
> > {I2CM14}: Master Interrupt Status Register
> > {I2CM18}: Master Command/Status Register
> > {I2CM1C}: Master DMA Buffer Length Register
> > {I2CS20}: Slave~ Interrupt Control Register
> > {I2CS24}: Slave~ Interrupt Status Register
> > {I2CS28}: Slave~ Command/Status Register
> > {I2CS2C}: Slave~ DMA Buffer Length Register
> > {I2CM30}: Master DMA Mode Tx Buffer Base Address
> > {I2CM34}: Master DMA Mode Rx Buffer Base Address
> > {I2CS38}: Slave~ DMA Mode Tx Buffer Base Address
> > {I2CS3C}: Slave~ DMA Mode Rx Buffer Base Address
> > {I2CS40}: Slave Device Address Register
> > {I2CM48}: Master DMA Length Status Register
> > {I2CS4C}: Slave DMA Length Status Register
> > {I2CC50}: Current DMA Operating Address Status
> > {I2CC54}: Current DMA Operating Length Status
> >
> > Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
> > ---
> > drivers/i2c/busses/Kconfig | 23 +-
> > drivers/i2c/busses/Makefile | 1 +
> > drivers/i2c/busses/i2c-ast2600.c | 1038
> > ++++++++++++++++++++++++++++++
> > 3 files changed, 1054 insertions(+), 8 deletions(-) create mode
> > 100644 drivers/i2c/busses/i2c-ast2600.c
> >
> [...]
> > diff --git a/drivers/i2c/busses/i2c-ast2600.c
> > b/drivers/i2c/busses/i2c-ast2600.c
> > new file mode 100644
> > index 000000000000..15e600ff50ec
> > --- /dev/null
> > +++ b/drivers/i2c/busses/i2c-ast2600.c
> > @@ -0,0 +1,1038 @@
> [...]
> > +static int ast2600_i2c_probe(struct platform_device *pdev) {
> >
> [...]
> > + i2c_bus->rst = devm_reset_control_get_shared(dev, NULL);
> > + if (IS_ERR(i2c_bus->rst))
> > + return dev_err_probe(dev, PTR_ERR(i2c_bus->rst), "Missing reset
> > +ctrl\n");
>
> What ...
>
> > + i2c_bus->rst = devm_reset_control_get_shared_deasserted(dev, NULL);
> > + if (IS_ERR(i2c_bus->rst))
> > + return dev_err_probe(dev, PTR_ERR(i2c_bus->rst), "Missing reset
> > +ctrl\n");
>
> ... is this?
OH, my mistake. I will use devm_reset_control_get_shared_deasserted().
>
> Choose one. If you use 1), call reset_control_deassert() somewhere. If you use
> 2), remove reset_control_assert() below.
Yes, will remove.
>
> [...]
> > +static void ast2600_i2c_remove(struct platform_device *pdev) {
> > + struct ast2600_i2c_bus *i2c_bus = platform_get_drvdata(pdev);
> > +
> > + /* Disable everything. */
> > + writel(0, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL);
> > + writel(0, i2c_bus->reg_base + AST2600_I2CM_IER);
> > + reset_control_assert(i2c_bus->rst);
>
> Drop if using devm_reset_control_get_shared_deasserted()
>
> regards
> Philipp
^ permalink raw reply [flat|nested] 8+ messages in thread
* RE: [PATCH v17 1/3] dt-bindings: i2c: aspeed,i2c.yaml: add transfer-mode and global-regs properties and update example
2025-08-14 22:30 ` Rob Herring
@ 2025-08-15 7:06 ` Ryan Chen
0 siblings, 0 replies; 8+ messages in thread
From: Ryan Chen @ 2025-08-15 7:06 UTC (permalink / raw)
To: Rob Herring
Cc: benh@kernel.crashing.org, joel@jms.id.au, andi.shyti@kernel.org,
krzk+dt@kernel.org, conor+dt@kernel.org,
andrew@codeconstruct.com.au, p.zabel@pengutronix.de,
andriy.shevchenko@linux.intel.com, naresh.solanki@9elements.com,
linux-i2c@vger.kernel.org, openbmc@lists.ozlabs.org,
devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org
> Subject: Re: [PATCH v17 1/3] dt-bindings: i2c: aspeed,i2c.yaml: add
> transfer-mode and global-regs properties and update example
>
> On Thu, Aug 14, 2025 at 04:41:54PM +0800, Ryan Chen wrote:
> > - Add property "aspeed,global-regs" to get phandle set global
> > register, for register mode selection and clock divider control.
> > - Add an optional property "aspeed,transfer-mode" to allow device tree
> > to specify the desired transfer method used by each I2C controller
> > instance.
> > - Update example to demonstrate usage of 'aspeed,global-regs' and
> > 'aspeed,transfer-mode' for AST2600 I2C controller.
>
> All of this is evident reading the patch. Explain here why you need this change.
The AST2600 I2C controller supports three transfer modes: byte, buffer, and DMA.
To allow board designers and firmware to explicitly select the preferred transfer mode
for each controller instance, this patch introduces the aspeed,transfer-mode property
in the device tree binding.
On AST2600, each I2C controller can operate in either the legacy or the new
register mode and clock divider control, selectable by a global register setting.
>
> >
> > Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
> > ---
> > .../devicetree/bindings/i2c/aspeed,i2c.yaml | 39 +++++++++++++++++++
> > 1 file changed, 39 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
> > b/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
> > index 5b9bd2feda3b..2a9f7d1d2ea1 100644
> > --- a/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
> > +++ b/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
> > @@ -44,6 +44,34 @@ properties:
> > description: frequency of the bus clock in Hz defaults to 100 kHz when
> not
> > specified
> >
> > + aspeed,transfer-mode:
> > + description: |
> > + ASPEED ast2600 platform equipped with 16 I2C controllers each i2c
> controller
> > + have 1 byte transfer buffer(byte mode), 32 bytes buffer(buffer mode),
> and
> > + share a DMA engine.
> > + Select I2C transfer mode for this controller. Supported values are:
> > + - "byte": Use 1 byte for i2c transmit (1-byte buffer).
> > + - "buffer": Use buffer (32-byte buffer) for i2c transmit. (default)
> > + Better performance then byte mode.
>
> If no 'aspeed,transfer-mode' property defaults to buffer mode, you never need
> 'aspeed,transfer-mode = "buffer"'.
>
> When would you ever use "byte" mode? Sometimes you want worse
> performance? That makes no sense.
>
> I feel like we already discussed this, but I'm not going to dig thru 17 versions to
> see.
Yes, my original through is dma and buffer property selection at v15, v16.
The reason for keeping "byte" mode is to support use cases reported by
other users (for example, as raised by Yikai in the above thread),
where certain I2C devices or board configurations only function
correctly in byte mode. This is not a common case, but providing
this flexibility avoids the need for downstream patches or hacks.
https://patchwork.ozlabs.org/project/linux-aspeed/patch/20241007035235.2254138-3-ryan_chen@aspeedtech.com/#3412650
Yikai yikai.tsai.wiwynn@gmail.com
>
> > + - "dma": Each controller DMA mode is shared DMA engine. The
> AST2600 SoC
> > + provides a single DMA engine shared for 16 I2C
> controllers,
> > + so only a limited number of controllers can use DMA
> simultaneously.
> > + Therefore, the DTS must explicitly assign which
> controllers are
> > + configured to use DMA.
> > + Only one mode can be selected per controller.
>
> The only thing that really makes sense is dma, and you need 1 boolean
> property for that. IOW, what you had on v10 which we gave reviewed-by 2+
> years ago.
>
> Do you have any actual test results or usecase that show DMA is useful here?
> Typical I2C xfers are not streaming large amounts of data to justify the setup
> costs of DMA. It wouldn't surprise me if DMA was actually slower.
>
For AST2600 used in server platforms, MCTP over I2C often requires transferring large
data blocks (e.g., 512 bytes per message). In buffer mode, this results in 32 interrupts
per transaction, while DMA mode reduces this to a single interrupt, significantly
lowering CPU load. We have observed measurable CPU utilization improvements
when using DMA mode for such use cases.
> > + On AST2600, each controller supports all three modes.
> > + If not specified, buffer mode is used by default.
> > + enum:
> > + - byte
> > + - buffer
> > + - dma
> > +
> > + aspeed,global-regs:
> > + $ref: /schemas/types.yaml#/definitions/phandle
> > + description: |
>
> Don't need '|'. Read the documentation about when it is needed or not
> needed.
Thanks, will remove it.
>
> > + The phandle of i2c global register node, For control the i2c register
> > + define selection, clock divider mode selection and clock divider
> control.
> > +
> > required:
> > - reg
> > - compatible
> > @@ -66,3 +94,14 @@ examples:
> > interrupts = <0>;
> > interrupt-parent = <&i2c_ic>;
> > };
> > + - |
> > + #include <dt-bindings/interrupt-controller/arm-gic.h>
> > + i2c1: i2c@80 {
> > + compatible = "aspeed,ast2600-i2c-bus";
> > + reg = <0x80 0x80>, <0xc00 0x20>;
> > + aspeed,global-regs = <&i2c_global>;
> > + clocks = <&syscon ASPEED_CLK_APB>;
> > + resets = <&syscon ASPEED_RESET_I2C>;
> > + interrupts = <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>;
> > + aspeed,transfer-mode = "buffer";
> > + };
> > --
> > 2.34.1
> >
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2025-08-15 7:21 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-08-14 8:41 [PATCH v17 0/3] Add ASPEED AST2600 I2C controller driver Ryan Chen
2025-08-14 8:41 ` [PATCH v17 1/3] dt-bindings: i2c: aspeed,i2c.yaml: add transfer-mode and global-regs properties and update example Ryan Chen
2025-08-14 22:30 ` Rob Herring
2025-08-15 7:06 ` Ryan Chen
2025-08-14 8:41 ` [PATCH v17 2/3] i2c: ast2600: Add controller driver for new register layout Ryan Chen
2025-08-14 10:42 ` Philipp Zabel
2025-08-15 5:36 ` Ryan Chen
2025-08-14 8:41 ` [PATCH v17 3/3] i2c: ast2600: Add target mode support Ryan Chen
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