From 5844564143575a8dbcbcece0084da059faeca5df Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Fri, 31 Mar 2023 17:15:01 +0800 Subject: [PATCH] i3c: ast2600: Add AST2600 platform-specific driver Now that we have platform-specific infrastructure for the dw i3c driver, add platform support for the ASPEED AST2600 SoC. The AST2600 has a small set of "i3c global" registers, providing platform-level i3c configuration outside of the i3c core. For the ast2600, we need a couple of extra setup operations: - on probe: find the i3c global register set and parse the SDA pullup resistor values - on init: set the pullups accordingly, and set the i3c instance IDs Signed-off-by: Jeremy Kerr Reviewed-by: Joel Stanley Link: https://lore.kernel.org/r/20230331091501.3800299-4-jk@codeconstruct.com.au Signed-off-by: Alexandre Belloni --- MAINTAINERS | 6 + drivers/i3c/master/Kconfig | 14 ++ drivers/i3c/master/Makefile | 1 + drivers/i3c/master/ast2600-i3c-master.c | 168 ++++++++++++++++++++++++ 4 files changed, 189 insertions(+) create mode 100644 drivers/i3c/master/ast2600-i3c-master.c diff --git a/MAINTAINERS b/MAINTAINERS index 8d5bc223f305..cb91cc18df58 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -9713,6 +9713,12 @@ S: Orphan F: Documentation/devicetree/bindings/i3c/snps,dw-i3c-master.yaml F: drivers/i3c/master/dw* +I3C DRIVER FOR ASPEED AST2600 +M: Jeremy Kerr +S: Maintained +F: Documentation/devicetree/bindings/i3c/aspeed,ast2600-i3c.yaml +F: drivers/i3c/master/ast2600-i3c-master.c + I3C SUBSYSTEM M: Alexandre Belloni L: linux-i3c@lists.infradead.org (moderated for non-subscribers) diff --git a/drivers/i3c/master/Kconfig b/drivers/i3c/master/Kconfig index 3b8f95916f46..90dee3ec5520 100644 --- a/drivers/i3c/master/Kconfig +++ b/drivers/i3c/master/Kconfig @@ -22,6 +22,20 @@ config DW_I3C_MASTER This driver can also be built as a module. If so, the module will be called dw-i3c-master. +config AST2600_I3C_MASTER + tristate "ASPEED AST2600 I3C master driver" + depends on DW_I3C_MASTER + depends on ARCH_ASPEED || COMPILE_TEST + select MFD_SYSCON + help + Support for ASPEED AST2600 I3C Controller. + + This hardware is an instance of the DW I3C controller; this + driver adds platform- specific support for AST2600 hardware. + + This driver can also be built as a module. If so, the module + will be called ast2600-i3c-master. + config SVC_I3C_MASTER tristate "Silvaco I3C Dual-Role Master driver" depends on I3C diff --git a/drivers/i3c/master/Makefile b/drivers/i3c/master/Makefile index b3fee0f690b2..3e97960160bc 100644 --- a/drivers/i3c/master/Makefile +++ b/drivers/i3c/master/Makefile @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0-only obj-$(CONFIG_CDNS_I3C_MASTER) += i3c-master-cdns.o obj-$(CONFIG_DW_I3C_MASTER) += dw-i3c-master.o +obj-$(CONFIG_AST2600_I3C_MASTER) += ast2600-i3c-master.o obj-$(CONFIG_SVC_I3C_MASTER) += svc-i3c-master.o obj-$(CONFIG_MIPI_I3C_HCI) += mipi-i3c-hci/ diff --git a/drivers/i3c/master/ast2600-i3c-master.c b/drivers/i3c/master/ast2600-i3c-master.c new file mode 100644 index 000000000000..b3f0fe1e63c3 --- /dev/null +++ b/drivers/i3c/master/ast2600-i3c-master.c @@ -0,0 +1,168 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2023 Code Construct + * + * Author: Jeremy Kerr + */ + +#include +#include +#include +#include +#include +#include + +#include "dw-i3c-master.h" + +/* AST2600-specific global register set */ +#define AST2600_I3CG_REG0(idx) (((idx) * 4 * 4) + 0x10) +#define AST2600_I3CG_REG1(idx) (((idx) * 4 * 4) + 0x14) + +#define AST2600_I3CG_REG0_SDA_PULLUP_EN_MASK GENMASK(29, 28) +#define AST2600_I3CG_REG0_SDA_PULLUP_EN_2K (0x0 << 28) +#define AST2600_I3CG_REG0_SDA_PULLUP_EN_750 (0x2 << 28) + +#define AST2600_I3CG_REG1_I2C_MODE BIT(0) +#define AST2600_I3CG_REG1_TEST_MODE BIT(1) +#define AST2600_I3CG_REG1_ACT_MODE_MASK GENMASK(3, 2) +#define AST2600_I3CG_REG1_ACT_MODE(x) (((x) << 2) & AST2600_I3CG_REG1_ACT_MODE_MASK) +#define AST2600_I3CG_REG1_PENDING_INT_MASK GENMASK(7, 4) +#define AST2600_I3CG_REG1_PENDING_INT(x) (((x) << 4) & AST2600_I3CG_REG1_PENDING_INT_MASK) +#define AST2600_I3CG_REG1_SA_MASK GENMASK(14, 8) +#define AST2600_I3CG_REG1_SA(x) (((x) << 8) & AST2600_I3CG_REG1_SA_MASK) +#define AST2600_I3CG_REG1_SA_EN BIT(15) +#define AST2600_I3CG_REG1_INST_ID_MASK GENMASK(19, 16) +#define AST2600_I3CG_REG1_INST_ID(x) (((x) << 16) & AST2600_I3CG_REG1_INST_ID_MASK) + +#define AST2600_DEFAULT_SDA_PULLUP_OHMS 2000 + +struct ast2600_i3c { + struct dw_i3c_master dw; + struct regmap *global_regs; + unsigned int global_idx; + unsigned int sda_pullup; +}; + +static struct ast2600_i3c *to_ast2600_i3c(struct dw_i3c_master *dw) +{ + return container_of(dw, struct ast2600_i3c, dw); +} + +static int ast2600_i3c_pullup_to_reg(unsigned int ohms, u32 *regp) +{ + u32 reg; + + switch (ohms) { + case 2000: + reg = AST2600_I3CG_REG0_SDA_PULLUP_EN_2K; + break; + case 750: + reg = AST2600_I3CG_REG0_SDA_PULLUP_EN_750; + break; + case 545: + reg = AST2600_I3CG_REG0_SDA_PULLUP_EN_2K | + AST2600_I3CG_REG0_SDA_PULLUP_EN_750; + break; + default: + return -EINVAL; + } + + if (regp) + *regp = reg; + + return 0; +} + +static int ast2600_i3c_init(struct dw_i3c_master *dw) +{ + struct ast2600_i3c *i3c = to_ast2600_i3c(dw); + u32 reg = 0; + int rc; + + /* reg0: set SDA pullup values */ + rc = ast2600_i3c_pullup_to_reg(i3c->sda_pullup, ®); + if (rc) + return rc; + + rc = regmap_write(i3c->global_regs, + AST2600_I3CG_REG0(i3c->global_idx), reg); + if (rc) + return rc; + + /* reg1: set up the instance id, but leave everything else disabled, + * as it's all for client mode + */ + reg = AST2600_I3CG_REG1_INST_ID(i3c->global_idx); + rc = regmap_write(i3c->global_regs, + AST2600_I3CG_REG1(i3c->global_idx), reg); + + return rc; +} + +const struct dw_i3c_platform_ops ast2600_i3c_ops = { + .init = ast2600_i3c_init, +}; + +static int ast2600_i3c_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct of_phandle_args gspec; + struct ast2600_i3c *i3c; + int rc; + + i3c = devm_kzalloc(&pdev->dev, sizeof(*i3c), GFP_KERNEL); + if (!i3c) + return -ENOMEM; + + rc = of_parse_phandle_with_fixed_args(np, "aspeed,global-regs", 1, 0, + &gspec); + if (rc) + return -ENODEV; + + i3c->global_regs = syscon_node_to_regmap(gspec.np); + of_node_put(gspec.np); + + if (IS_ERR(i3c->global_regs)) + return PTR_ERR(i3c->global_regs); + + i3c->global_idx = gspec.args[0]; + + rc = of_property_read_u32(np, "sda-pullup-ohms", &i3c->sda_pullup); + if (rc) + i3c->sda_pullup = AST2600_DEFAULT_SDA_PULLUP_OHMS; + + rc = ast2600_i3c_pullup_to_reg(i3c->sda_pullup, NULL); + if (rc) + dev_err(&pdev->dev, "invalid sda-pullup value %d\n", + i3c->sda_pullup); + + i3c->dw.platform_ops = &ast2600_i3c_ops; + return dw_i3c_common_probe(&i3c->dw, pdev); +} + +static void ast2600_i3c_remove(struct platform_device *pdev) +{ + struct dw_i3c_master *dw_i3c = platform_get_drvdata(pdev); + + dw_i3c_common_remove(dw_i3c); +} + +static const struct of_device_id ast2600_i3c_master_of_match[] = { + { .compatible = "aspeed,ast2600-i3c", }, + {}, +}; +MODULE_DEVICE_TABLE(of, ast2600_i3c_master_of_match); + +static struct platform_driver ast2600_i3c_driver = { + .probe = ast2600_i3c_probe, + .remove_new = ast2600_i3c_remove, + .driver = { + .name = "ast2600-i3c-master", + .of_match_table = ast2600_i3c_master_of_match, + }, +}; +module_platform_driver(ast2600_i3c_driver); + +MODULE_AUTHOR("Jeremy Kerr "); +MODULE_DESCRIPTION("ASPEED AST2600 I3C driver"); +MODULE_LICENSE("GPL");