Commit 58445641 authored by Jeremy Kerr's avatar Jeremy Kerr Committed by Alexandre Belloni
Browse files

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: default avatarJeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: default avatarJoel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20230331091501.3800299-4-jk@codeconstruct.com.au


Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent 21203e09

MAINTAINERS

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@@ -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 <jk@codeconstruct.com.au>









S:	Maintained









F:	Documentation/devicetree/bindings/i3c/aspeed,ast2600-i3c.yaml









F:	drivers/i3c/master/ast2600-i3c-master.c

















I3C SUBSYSTEM









M:	Alexandre Belloni <alexandre.belloni@bootlin.com>









L:	linux-i3c@lists.infradead.org (moderated for non-subscribers)
































drivers/i3c/master/Kconfig



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@@ -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
































drivers/i3c/master/Makefile



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# 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/
























drivers/i3c/master/ast2600-i3c-master.c
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// SPDX-License-Identifier: GPL-2.0









/*









 * Copyright (c) 2023 Code Construct









 *









 * Author: Jeremy Kerr <jk@codeconstruct.com.au>









 */



















#include <linux/mfd/syscon.h>









#include <linux/module.h>









#include <linux/of.h>









#include <linux/of_device.h>









#include <linux/platform_device.h>









#include <linux/regmap.h>



















#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, &reg);









	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 <jk@codeconstruct.com.au>");









MODULE_DESCRIPTION("ASPEED AST2600 I3C driver");









MODULE_LICENSE("GPL");